1 15 8 Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 094 Folder The folder containing the original item. 2384 Series The series number of the original item. Series IV Subseries IV Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Source A related resource from which the described resource is derived Settimana 3 Date A point or period of time associated with an event in the lifecycle of the resource 1984-03-01 Title A name given to the resource Il Verde Degli Alberi Lungo Vai Vignazzola Subject The topic of the resource health studies ecological recovery Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 094 Folder The folder containing the original item. 2350 Series The series number of the original item. Series IV Subseries IV Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Source A related resource from which the described resource is derived Settimana 3 Date A point or period of time associated with an event in the lifecycle of the resource 1983-07-01 Title A name given to the resource Seveso Sett Anni Dopo: Buona la Salute della Popolazione [Seveso Seven Years Later: the Population's Good Health] Subject The topic of the resource health monitoring ecological recovery international cooperation Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 093 Folder The folder containing the original item. 2338 Series The series number of the original item. Series IV Subseries IV Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Source A related resource from which the described resource is derived Settimana 3 Date A point or period of time associated with an event in the lifecycle of the resource 1983-04-01 Title A name given to the resource Nessun Rischio per l'Uomo e Per l'Ambiente [No Risk for Humans and for the Environment] Subject The topic of the resource risk assessment decontamination ecological recovery toxic wastes https://www.nal.usda.gov/exhibits/speccoll/files/original/5fdfbca8921d51cb08e5d2886227f347.pdf 03889e0b3d34095267d017472e4cc537 PDF Text Text ItemD Number °1961 Author Minarik. Charles E. Corporate Author RepOrt/ArtiGlB Title Herbicide Damage to Rubber and Fruil Trees in Cambodia Journal/Book Title Year 1969 Month/Day Ju| 12 v Color Number of Hugos ° Pages 9 and 10 were paperclipped. as noted on the Routing and transmittal slip. Handwritten note on File Summary Form: "We have no record of herbicide missions this date and place. D. 28 Dec. 83." Monday. July 30, 2001 Page 1961 of 1993 �DtPAi<7V.2.NT Or THE ARMY ' <f '"~>'- '" FOST 2I7S1CK O ..»>'': 21701 !N «c?LY acre* TO: SM'JFD-PSL SUBJECT: 11 December 1969 Report of Cambodian Rubber Damage SEE DISTRIBUTION inclosed is a copy of z.\z report of dai-age to Cambodian rubber plantations prepared by the four-man survey team following a survey in June 1969. This version of che report lias been released to the press by the State Department. 70R THE COMMANDER; 1 Incl as C. E. MINARIK Director, Plant Sciences DISTRIBUTION: Mr. A. E. Hayward, OSD, DDR&E Dr. K. C. Emerson, OASA (R&D) MAJ M. L. Sanches, OACSFOR LTC William J. Henderson, OCRD Mr. E. M. Hamory, USAMC Mr. Werner Beyth, USAMUCOM COL B. M. Whitesides, Cml Ops Div, MACV J-3 Mr. C. R. Heineman, JTCG/CB, Naval Air Sys Crad W. Vandeventer, SAOQT, SAAMA, Kelly AFB Mr. M. G. Solomon, ATCB, Eglin AFB ' CPT R. Richter, AFATL, Eglin AFB Mr. Mitchell Modrall, USA Cml Center & School CO, Ft Det Sci Dir, Ft Det Mr. K. Irish, PP&C Ofc, Ft Det Ch, Pit Physiol Div, Ft Det Laboratories �t •- I BE RETIRED A REPORT OH HERBICIDE DAMAGE TO RUBBER AND FRUIT TREES IN CAMBODIA DECOCTED BY BY .BY TAG CHARIZS E. HINARDC x./ 7 JACK B. SHlMATE NADIR G. VAKILI FRED H. TSCHIRLEI .• r-*. SAIGON 12 July 1969 �TABLE OF CONTENTS INTRODUCTION , Purpose • Saigon Briefings . Cambodia: Itinerary and Contacts Made • 1 2 2 ANALYSIS OF DAMAGE AND CAUSES Area and Pattern of Damage Severity of Damage Causes of Damage Permanence of Damage Mitigation of Herbicide Effects . _ .. .. 4 4 8 11 13 SUMMARY AND CONCLUSIONS 14 ACKNOWLEDGEMENTS 15 APPENDIXES A. Programme de Sejour et d'e Visite des Experts Americains B. Map Showing Principal Cambodian Rubber Plantations* Maximum Extent of Herbicide Effect, and Boundary of Tay Ninh Spray Target C. Maps Showing Areas and Severity of Herbicide Effect at Chalang-Prekchlong and Mimot-Kantroy Plantations D. Rapport du Comite" Charge" du Constat et de 1* Evaluation des De"gats Dus aux Epandages des Produits Defoliants par les Avions Americano-Subvietnamiens E. Selected Photographs �INTRODUCTION On June 2, ,1969 the United States Government received notice of a charge by the Cambodian Government that major defoliation damage to Cambodian rubber plantations near the border of the Republic of Viet-Nam (RVN) had occurred as the result of U.S. defoliation activity. In replying to this charge, the U.S. State. Department offered to send-a team of experts to examine the area of al'leged damage and the Cambodian Government agreed. The team members were selected and met in Saigon on June 27, • 1969 for a formal briefing. Members of the four-man team included: Dr. Charles E. Minarik, Director.. Plant Sciences Laboratories .. Department of Defense Jack B. Shumate, Chief Forestry Branch Office of Commercial and Capital Assistance Agency for International Development Saigon, Viet-Nam Dr. Fred H. Tschirley, Assistant Chief Crop Protection Research Branch Agricultural Research Service Beltsville, Maryland Dr. Nader G. Vakili, Agronomy Adviser Office of Development and Domestic Production • Agency for International Development Saigon, Viet-Nam Purpose The purpose of the trip was to determine the cause, severity, "origin, ancT"ex'tent~of reported~damage to rubber and fruit trees. �Saigon Briefings Team members received a briefing from military and State Department personnel on June 27. They were provided with pertinent information on military operations—especially defoliation activity—near the Cambodian border. Three of the team members went via helicopter to Xuan Loc on June 28 to visit with Mr. Poliniere of the Rubber Institute. On June 29, the group travelled via helicopter to the defoliation target area in Tay Ninh Province to observe the defoliated areas from which-', drift of the herbicide may have- caused damage to rubber and fruit trees in Cambodia. On June 30, the four-man team left by commercial aircraft for Phnom Penh. Cambodia: Itinerary and Contacts Made Upon arrival in Phnom Penh, Cambodia, shortly.after noon on June 30, the team was met by a representative of the Cambodian Foreign Ministry, by Mr. Mack Williams, Australian Deputy Chief of Mission, and by Mr. Neil Manton, Third Secretary and Vice Consul. Mr. Manton handled all local arrangements and served as liaison officer for the team during the entire stay in Cambodia. After checking in at the Monorom Hotel, the team went to the Australian Embassy for a briefing.' Members of the embassy staff contacted included Mr. Graham Feakes, Ambassador; Mr. Mack Williams; and Mr. Neil Manton. On Tuesday July 1, a meeting was held with Cambodian • representatives who outlined conditions as they saw them and presented a proposed schedule for field travel (Appendix A). ; We agreed with the schedule, and a general discussion followed. Individuals attending the meeting in addition to team members and . Mr. Manton included:Mr. Min Sarim, Ministry of Agriculture, Chairman of the committee appointed by the Cambodian Government to study and report on damage to rubber trees, fruit trees and farm crops. " ' _.- . .[ '• j \ | j ! j j 'j �fir". King Un, Director of Agriculture ee member i Mr . Suon Kaset, Director ot Water and Forestry - Committee member Mr. Ho Toug Lip, • inarch Agronomist, Ministry of Agriculture - Committee member Field travel began on July 2, with a visit; to the Chup rubber plantation and an overflight in small fixed -wing aircraft, of the entire area of alleged damage. Purpose of the visit was to see an undamaged plantation (Chup) in operation and get a general picture' of the Jatr.aged area. People contacted at Chup were: Mr. Keas Keth Caimira, Director General of SOKAR; Mr. Francis Ninane, .igrcuonist, Mr. Chai Kim Chun, chemist, and Mr.. Gilbert Do Coninck, pathologist, of the Rubber Research Institute (IRCC); cxuc! it E'i^Oy , • iia^er of the Chup Plantation. Travel from and _o Pnno..i f-fciih Wc*^ by Dakota aircraft and over the Chup, Mtiiiot and acner moldings by small, Jingle-cni^ae aircraft, both furnished by the Royal Cambodian Air Force. Ground transportation was f-.r.'iished by plantation otJficials and the Cambodian Governr.wnr. furnished security forces ac all tiiiies. Team and committee members returned -.0 .'hnoi: Penh e<". .h .light. v.- . uiy 3, ' a. .d 5, A i .ravelleu to M-.rr.ot vi*. Dakota aircraft J.I.Q Lneii by car ^h^oughoui. the are^ of reported oaniage. Major _ -ioui:r pla cationf visited included: Chipeang, Chipes, Dar, Chalang, Mimot Kantroy, .<rek and Prek Chlong. The group also visited a number of other areas to insi-ecc fruit trees, farm cropsr orr.amental plantings, a teak plantation, a;id natural forest area. Key personnel -ontact<d at the Mimot headquari --s included: Mr. H. Say, Director vjonera^. - Mimot; Mr. Audurcau, I ^rccLor of farm operations Mireot; Mr. Girandel, Administraeive Officer - Mimot. July 6-7. No formal schedule. and forest areas. Team visited undamaged farra A helicopter flight over the entire damaged area was scheduled for July 8, but was postponed ona day. The team took advantage of �this tine to meee with the French Ambassador, the Canadian members of the International Control Commission, the Australian Embassy staff and the Cambodian Minister of Agriculture, Mr. Chuon Saodi. An Alouet^te II helicopter was made available on July 9 and the investigating team made an overflight of the entire area under study. We returned to Phnom Penh in the afternoon and left for Viet-Nam, arriving in Saigon shortly after 1700 hours. ANALYSIS OF DAMAGE AND CAUSES Area and Pattern of Damage Representatives of the Cambodian Government had prepared a map showing the extent of the damaged area. The boundary representing the perimeter of the damaged area.is .shown on the enclosed map (Appendix B). In audition, we were also supplied with maps of the Mirnot and Prek Chlong plantations that showed rubber trees severely damaged (more than 50 percent defoliation) and slightly damaged (less than 50 percent defoliation). These maps (Appendix C) were prepared at the time of maximum defoliation-before refoliation had begun. Our own observations confirmed the -findings of the Cambodian investigating committee. The total area on which damage occurred was approximately 700 square kilometers or 70,000 hectares. The Cambodian Government claimed damage on about 15,000 hectares, which represents the area in rubber and fruit. The principal damage reported by the Cambodian investigating committee, and confirmed by us, was through the Dar and Prek Chlong plantations. Lesser damage was noted to the west on the'Krek plantation and to the east on the Mimot plantation. Severity of Damage The degree of plant response to the herbicide varied from a very slight reaction showing discoloration of older leaves, and "atrbph~y~~of"" "th"e~~yourig~ leaves, ~tb"~IOO "per cent~"def6riat"ioh~and ~~cTie-EaclT of one to four years of branch growth. We were told by the �ns that: normal flower development was prevented in teak (Tjf^cjiCKKi Kr;.ridis), resulting in the failure to product seed. The defoliant caused malformation of fruits of jackfruit, durian and guava, and in severe cases resulted in rot and fall of the fruits. The vegetable crops mentioned below were either destroyed and replanted by the time of this repor* or were left in the field and backyards unattended. The degree of plant reaction to the herbicide differed among jpcoies. Within a species, the degree of response was conditioned by variation in varietal tolerance, age of the plant, stage of growth (active or quiescent) of. the plant, and dosage received. Exceptions may be found for any general statement about the nature of damage to crops. However, the following statements are based on two years of surveys and experience with tropical crops in Viet-Nam. Each crop is discussed separately with the .craps least, tolerant to herbicides mentioned first, followed by the nore tolerant ones. ' Casurina Pine 01 Australian Pine (Casurina equisetifolia). This plant is used cs a shade tree. It is the species most sensitive to defoliants used in v/iet-Nam. After treatment it's foliage turns Drown and Jails, branches die back, and1 bark peels away from the trunk. Ont treatment v/itn a heavy dosage is sufficient to cause dit-back jf most branches and ofcen th^- ^vee is killed. Jackfruit (Arcocarj as Integra.). This fruit tree is easily /,rcn-:r. and popular in this region. It is highly sensitive to dcfoliancs, responding with'very rapid defoliation and die-back of branches. Young fruit may be malformed and fall. However, trees refoliate rapidly a-.id within 6 to 3 month-s '^?.gin to look normal. Because • fiiiii. badt, originate from the trv.nk and limbs of the tree, die-back of the small branches does not result in fruit loss during the next season, but may cause a reduction in yield. Rubber (Kevca ty.'aj1.1 iGr.r.is) . The v.ober tree is highly sensitive i-G defoliants, buc the degree of rv sponse varies among varieties. A heavy rate of defoliant, ;uch as io used normally in Viet-Nam, causes coaaplisCe defoliation and d^^-back of several years' growth. Refoliation usually begins within u aioach, bui_ the speed of refolie-tion is dependent �upon the sensitivity of the variety. The less sensitive a variety, the faster it refoliatei:. New loaves often show leaf malformation for a period of two to four months, demanding on the dosage received. After six months, growth begins to appear normal and the plantation canopy is essentially uniform within 3 to 12 months. Wood-rotting fungi may enter limbs and trunks by way of dead branches. Young (3 to 5-year old) trees on the Dar plantation were severely defoliated and showed extensive die-back. This was due at least in part to the openness of the canopy in the young plant.ation, which permitted coverage of the entire plant by the defoliant droplets. At Prek Chlong plantations, 5-year old trees of the variety SPRM-1 suffered 13 feet of branch die-back. Seedlings 5 to 7 months old were killed by the herbicides. The most common rubber varieties in Cambodia are PR-107, PB-36, and AVROS-50, each representing about 30.percent of the total acreage. The variety PB-S6 is most tolerant to defoliants, PR-107 is quite sensitive and AVROS-50 most sensitive. Other .; varieties are variably sensitive, but are of such minor importance that they are not discussed here. Cainito or Star-apple (Chrysophy 11 am c_aini t o ) . This is a colorful fruit tree with purplish-brown foliage and fruit. Affected plants defoliate and young branches die back. However, this tree begins to refoliate within a month. The die-back of the terminal • branches results in complete loss of the next season's fruit crop. Kapok (Ceiba sp.). The cotton-like fibers developed in the large pods borne by this tree are used as stuffing for pillows and mattresses. This tree is abundantly planted in back yards and in hedgerows. It is highly sensitive to defoliant. Leaf malformation, discoloration and defoliation follows even after a small dose of herbicide. Kapok production during the next season is severely affected by death of the terminal brandies. Pineapple (Ananas comosus). The high dosage of the herbicide in some areas visited had resulted in leaf.folding and discoloration with malformation and loss of fruits. Bananas (Edible Musa varieties). The high defoliant dosage received in some areas visited had resulted in.reduction in size �.ir.d r.i. .'.formation of leaves, splaying of the leaf sheaths, elongation ol: tne fruits and brittJ enesy of the: plants. Plants treated while in fruit develop abnormal fruits and that condition may persist for approximately six months to a year and a half. Plains treated before they are in fruit do not: produce fruit. Teak. (Tectona ^randis; . This spec .us is intermediate in its re.spouse to defoliants. The young leaves are malformed, turn brown and fall, and flower development 15; impeded. The teak plantation.. in the Kimot area was imputed heavily by leaf -eating insects . 'The • damage caused oy the defoliants was relatively small in comparison to the damage caused by the leaf -eating insects. Coconut; (Cocos nuci.f era) . Coconut is one of the least sensitive crops. However, once the growing tip of this plant is affected, recovery is slow and sometimes trees die. ?c.ui • .. '..Caricc. p. .paya) . This is a sensitive plane that easily lob^s its f Lowers and fruits. Even though a plant may survive a moderate dosage of the herbicide, fruiting usually does not occur. x j (Paiaium y.iaiava). Guava is moderately sensitive. - \fi— *j- * Tne c eath of youi v. branches results in yield reduction during t^ next season's growth Refoliation occurs ratht rapidly. Li i-.pple (AiiiiOna re_t.__ici_!_?_: _ta ) . This fruit tree is .noderately colerant and recovers quickly. Sapodilla or Chicle (Achras ?.apotaj . Slightly sensitive. It can v/ithstand heavy herbicide dosages without suffering defoliation. Cit;r\.:s sp.. All citrus species e • only slightly sensitive to defolic.-.tb and the loss if- any, -.s negligible. The main loss in citrus is due co diseases and insect damage. Mango (Mane if era J-jn^.ca) . Very toJjrant. Flo'-'2r developr;ient :T.ay bt affected if d^i\,li..:-.t;s are c ^...lied betv;een the time of flov:er bud initiation and fruit set. Soursop (Annona inuricate). Very t.:lerc:nt. �Coffee (Coff^.a robusta), Very tolerant. Tomato family (Solanum sp.). sensitivity. , Bean family (Phascoins spp.). loss. Complete loss due to extreme Extremely sensitive. Cabbage family (Brassica sp.). to complete loss. . Moderately sensitive. Cucumber faintly (Cucuniis sp.)Partial to complete loss. Complete Partial Moderately sensitive. Cassava or Manioc (Maniho_t utilisima) . Highly sensitive. The above-ground portion of the plant may recover from defoliant: applications, but root formation is retarded. The extent of the damage to the crop is dependent upon the stage of growth at which plants are sprayed with herbicide. Peanuts (Arachis hypogaaa). This is a moderately, sensitive crop. Defoliants cause curling of the leaves and'reduction in pod formation. The extent of damage to the crop is dependent upon the. stage of growth at which plants are affected. Causes of Damage For the purpose of analyzing the causes of damage, a number of hypotheses were established and the available evidence brought to bear on eachJ The hypotheses considered were: (1) Drift occurred from defoliation operations in RVN, (2) direct overflight of the Dar and Prek Chlong plantations for the purpose of defoliation, (3) damage1 caused by drift from ground, spraying operations in Cambodia, (4) damage caused by disease, and (5) damage caused by poor' environmental conditions for growth of trees. Each of the hypotheses will be discussed separately. To obtain information on the possibility of the damage in Cambodia being caused by drift from defoliation operations in Tay Ninh Province, the team made a helicopter survey of defoliation �car sets i" that province: on Juno 29, 1969. It was__qu i t g_ a p pa rent th2JL_£i££0l.i_a_n_^_Jla4. <\ £iLt_l:<L across the border Ynto~cHjnbgclia~ ~ particularly on the ceiiLral aiKM^oi>j:_crn portions of__tnc_ Tay Niuh ta~rge~"ir. A similar _su_rvoy_ on JuJoLJL_19_0-2 on the Cambodian side" border 1 con_firrrie_d_ the e a r l e r o b s r v a t i o n . The defoliation reported immediately north of the border u n d o u b t e d l y resulted from the Tay Ninh defoliation operations of April-May, 1969. . '> • i Defoliation missions in Tay Ninh Province were flown on ; ! March 29 (7 aircraft), March 30 (5 & 7), Ajiri!__(?), April 16 ( ) , 3'' j April_19 (7), April 21 (5 & 5), Awril 24 ( ) April 25""(6), April 29 ( ) 5, ?! April To"(6), May 2 ( ) May 4 ( ) May i ( ) May 9 ( ) May 13 (7), 3, 6, 4, 4, May 14 ( ) May 16 ( ) May 18 ( ) May 21 ( ) May 22 ( ) May 23 ( 6, 9, 9, 4, 7, 6 May 27 ( ) June 1 ( ) and June 9 ( ) Discussions with the 9, 5, 6. . \ Cambodian committee elicited the information that the hcrbicidal [ effect was first noted in the period from April 20 to 25, 1969. .' ! Although the Cambodian conrnittee believed that 'drift may have • : : come from several missions in RVN, we disagree because ; r manioc and bougainvillea both indicated herbicidal damage at only one time or within a period of a few days. Thus, drift from missions :in RVN could...only include the first five missions. listecTirpova^'.J " ; " J Examination of the meteorological data provided' by the 12th . ' j Special Operations Squadron for April 19, 1969 discloses that • j at 1119 hours, when the spray run was made, the temperature was _ ! 90° F and the winds were "light and variable." Meteorological data from Chup, furnished by the Rubber Research Institute of Cambodia for the same day (at 1000 hours Cambodian time) shows temperature as 89° F and wind speed of 10 mph from the southsoutheast. The data from Chup are given in Table 1. g_ucjj_meteprological conditions are unfavorable for spray operations and unaouTTtedly were responsible for the spray drift that crossed the border onJ^IiajL.cki^c: and resulted in defoliation qf__£lie area inur.ediatcl.y__north of the border. We do not feel, howeve~r~^ th"at drift from the Tay Ninh missions caused damage to a distance of 18 to 20 kin above the Cambodian border. If spray drift were responsible for all of the damage observed, one would expect to see a reduction in severity of plant response with increasing distance from the point of application. This is not the case because rubber varieties 15 km north of the border were as severely affected as similar varieties closer to the border. Tapering off �10 • of effects was noted east: and west of the severely affected area. Our second hypothesis was that a direct overflight was made of the Dur-Prek Chlong plantations for the purpose of defoliation. The pattern of extent and degree of hcrbicidal effect fits this hypothesis more closely than any other. The response of a rather resistant species, such as banana at coordinates XU225045, XU095045, and XU190135, were indicative of heavier doses than one would expect from spray drift from south of the border. Some drift from the Tay Ninh operations up to and slightly beyond the border was evident. However, there was Lhen a /cone of somewhat lesser damage and still farther north'there war, once again severe damage. In addition, considerable hcrbicidal" effect was noted on native forest trees in an area centering approximately at coordinates XU110140.. That this'_ was caused by drift from RVN is highly unlikely. Only minor damage was noted on the Krck plantation. If the damage in Cambodia were the result of drift from RVN, Krek and Chipeang would be directly on course for prevailing SSi^ winds. Thus, the RVN missions on the west portion of the spray target would be ideally located for drift damage to Chipeang and Krek. - . However, the light damage at Krek is further circumstantial evidence that drift from RVN did not cause the major portion of the damage in Cambodia. The area of heavy rubber damage is about 60 sq km or 15,000 acres, principally in the Dar and Prek Chlong plantations. Assuming that a does of' approximately 0.5 - 1.0 Ibs. per acre was^required to produce the severity of plant responses noted, this would mean a deposit of 750 to 1500 gallons of defoliant, or 1 to 2 UC-123 -plane loads. It is highly unlikely that this quantity could have drifted over the border from the Tay Ninh defoliation operations. -This strengthens the view that damage was due to herbicide spray during a direct flight over the affected plantations. Thus, the evidence we have seen, though circumstantial, suggests strongly that damage was cuased by direct overflight. We do not deny, t'nac the damage could have been caused by drift. But the meteorologic conditions necessary to cause the damage pattern observed forces us to accept this as only a remote possibility.' �11 Y.t _..Lra ypo.:h jiK, d-i!'. frc i. grcui.c. cpray applications •_:; Cc.r.ibodiit, cannot DC joi.sideted ^-.•lonsly as a cause of the ... -iir-agi As far as cou" ' ^- determined, . "round .sprays with 1 :.ruir iiJi.-s similar Co ". inge or Whine h.\./<.: .jeen USJG in the i ublic. ^lun j.icions . ^imited spra^. :.ng with dalapon, a herbicice usec MC control grass, is practic on one1 of the plantations. .-•o.-/(iv:r . dalapci' doe:; not produce h<_ piant responses noted, nor d'les *t affect t ^..'.dlcaf plr.nts c. the usual dosage rates. Weccs i.i u.. young p ; i.ntii.^u ..re uorr.ia] ^ controlled mechanically ''e uy cutting. i-.Teeds are. .iot a problcr.i in the older plantings since jhe fei:i«_ shade of the rubber trees does not permit them to thrive. The uniformity of plant responses throughout this "large area would .--.eclude ground spray operations as the cause. Moreover, ci did p.ct see drums or Orange or White during our visit. i'r .. s _ ihasio ^ : disc ise as a cauai'i of the damage can be .'• '••'.-•'? ouv ted . K • disease organism attacks such a broad . <. . .L ^l_ir: species as xvas observed in the area of interest. . ;. .er L.ie p.: ant rei poases preval:..it throughout the area were yoical of those induced by Orange and White. Undamaged rubber .i:- a<i_, ioei.i .. damaged oricS shov.'ed minor disease symptoms ..-. i.Owl'iii.^ .pr -c.ch.ing the epidemic proportions that would have ...c i.. i =cesi._ry c -ausc. the v;idcsprcad defoliation. ...... i.o ;^»s ;vas "chi .; the damage in Cambodia may j. '. j^.en jtiuSeo Ly environ:r.ental conditions unfavorable for i, -/..:. Envirc. :ntal joiuliticns that prevailed in Cambodia dur .^ '.969 _re -^cli^vco to be unimportant with respect to the defoliation ,./f rubber and oth^r trees in Cambodia. Neither rubber nor fruit trees in areas adjacent, to the damaged area give an r.nc'.cc. !•'•.. chat 2daphi_- or clin:.- - -. factros were responsib le. -In i-.dditioii. the r-.;fol: ation ,.:hat ^s now occurring suggests that enviro; .. ^nta! factors are favorable foi satisfactory growth and production. T '--£_r __ •• .nc. of Damage ..«. .J no ind .,-.-.L ... uliat u..o c;. ,.:a^e to rubber or fruit crees is :3ri-anent. «u:-r^n_ . ' servat Lo, s in Cambodia lead only to the • _ • r, lu.'.cn that ':•./: x : ccc. -.ng The rate <.nd degree of ;7 ,. a.-.^ng i vcii'ious rubb ,: pieties complicates the . .. • Lovi .. cht cxcent r.har a _ .ic-r-ilizacion is not possible. A highly �12 susceptible variety such as AVROS-50 was co::iplet:oly defoliated, and refoliation ct this time, varies fro:n 5 Co 20 percent. A variety of moderate susceptibility may or may not have been completely defoliated and foliage on the trees at time of observation ranged from 20 to 70 percent. In the intermediately affected areas of the plantations resistant' varieties now have 70 percent or more of their normal foliage. In the final analysis, the degree and permanence of damage can only be equated in terms of latex production. Personne'l at the Rubber Research Institute maintain records on production by varieties for the large plantations. There are no good production data for the small holdings, but extrapolation of data fro™, the large plantations should provide a'reasonable estimate. These figures indicate chat recovery is occurring and normal yields may ultimately be obtained; however, appreciable production losses will be suffered in the interim. An example of damage and recovery experienced in Viet-Nam is the Gallia Plantation in Phuoc Tuy Province where one plane sprayed herbicide ORANGE directly over rubber trees in 1967. One year later the French manager of the plantation stated that the "trees' had refoliated 100 percent and production had returned to 90 percent. In the Herbicide Policy Review issued by the American Embassy, Saigon, 28 August 1968, a report by the CORDS Agricultural Adviser in Binh Long Province is quoted as £ollows: "The effects of defoliation have not been as disastrous as anti- cipated; refoliatioa has begun and blocks of trees marked off as lost will be able to be tapped again. The Policy Review continues, "Other preliminary evidence tends to substantiatefurther the view that herbicides may be less toxic to rubber trees than was previously thought." Rubber trees on the island of Phu Quoc have reportedly been sprayed intentionally three times with herbicide ORAKGE and have not been killed. �13 The inspection team feels tlu't an assessment of damage in terms of decreased late:-: production and decreased fruit production can best be made in July or August, 1970. The timing of the final assessment is important -- it should occur several months after the beginning of the 1970 rainy season. Ideally, the final assessment should be made by some of the same -- but not necessarily all -members of this inspection team plus an agricultural economist. One item of great concern to French plantation managers and to the Cambodians was the cost of support for the unemployed rubber tappers. There is no question but that the herbicide damage has disrupted the normal plantation operations and there must be a cost associated with that. Mitigation of Herbicide Effects Several practices to mitigate the long-term effects of defoliation had already been instituted. One severely damaged area, tapping was stopped because the net return exceeded production costs. Cessation of tapping would, in essence, husband the food reserves necessary for refoliation. Trees on less severely damaged areas were being tapped, but at 6-day rather than 3-day intervals. Tapping is proceeding as usual on trees that were only lightly damaged. Fertilization with a complete fertilizer was being practiced at one location. We encouraged this practice because we •believe it will increase the rate of refoliation. At one location on the .Bar plantation, the tops of 3-year old trees of Variety PR-107 were being removed in the hope that this would prevent further trans location of the herbicide. Topping done soon alter treatment (up to three days) would probably be effective, but downward translocation of the herbicide would certainly be completed during a period of six weeks. Thus, topping at this time would not affect herbicide translocation. A possible advantage �14 from Che topping wo aid be a clean v.-ound (the subject; wat; coated with petroleum) that would be less subject to attack by fungi than would be a wound caused by rotting of a dead branch. The condition of the rubber trees before chemical defoliation is believed to have been good. There is no reason to suspect that prior condition was a contributing factor to the degree or duration of damage from herbicides. The loss of production due co defoliation will vary with varieties and cannot be satisfactorily assessed now. - A reliable estimate of loss should be possible in July or August, 1970. SUMMARY AND CONCLUSIONS " ' ' 1 . Herbicide dar.agc in the southeastern -part of Konipong Cha-.n Province, Cambodia, was extensive due to a combination of two factors: (a) Defoliation _pf fruit jireeson the Cambodian^ side near th_e .border _was a result pf drift frojii spray operations in Tay Kinh Province, and (b) Defoliation of rubber, fruit, and forest -trees farther north was ., probably caused by a direct spray application by an unknown ^ ^ party on a north-south line running through the plantations of Dar and Trek Chlong. 2. Defoliation of rubber trees on the Dar and Prek Chlong plantations- was complete, but refoliation is in progress. 3. Few, if any, rubber trees have been killed. The degree and rate of refoliation will depend on the age of the tree, variety, and dosage received. 4. The differential susceptibility of rubber varieties to the herbicide applied is striking. All varieties are defoliated from a heavy dosage such as is used in RVN, but low dosages as would be expected frora drift result in a marked differential response. . ' • �15 5. Specie;; of fruit trees al.so vary in their rcspon.se to the herbicide. A docreasin;', rank of susceptibility is: jackfruit, cainito, duria:i, pineapple, papaya, guava, and 'mango. 6. A final assessment of damage should be mcde in July or August, 1970. Damage to rubber must be assessed on the basis of decreased .latex production. Data on latex production can be obtained fro:r. the Rubber Research Institute of Cambodia. 7. Damage to fruit trees in temporary. Loss of production from the trees should not continue for more than one year. ACKNOWLEDGEMENTS Many individuals ware helpful to the investigation team in carrying out its mission. Australian Ambassador Feakes ana his staff, particularly Deputy Chief of Mission Mack Williams, and Third Secretary and Vice Consul Neil Manton, v:ere most helpful in making arrangements for us in Cambodia end providing wise and appropriate counsel. • Among the Cambodians, Mr. Thach Phiern of the Foreign Ministry provided many services and accompanied us on all tcurs. The members of the Cambodian Committee appointed by the Minister of Agriculture to assess damages were factual and objective in their assessment of damages. They generated a feeling of trust in•• terms of both accuracy of observation and honesty in reporting, which made our job much easier. Members" of the Coircr.it tee who accompanied us were: Mr. Min Sarim, Director General of the Office of Land Development in charge of State Plantations Mr. King Un, Director of Agriculture Mr. Suon Kaset, Director of Water and Forests �16 Mr. lio Tons Lip, Research Agronomist; These men were with us on all tours and provided iv.uch necessary background information. Also helpful were Mr. Francis Kinane and Mr. Gilbert De Coninck of the Rubber Research Institute. Lunches were provided on three days by SOKJIAR, the Cambodian Government Tourist Information Agency. Lastly, personnel of the American Embassy and MACV provided us with accommodations, assisted in travel arrangements, and provided necessary background briefings, We are grateful and owe our thanks to all. �-- - • l*^ \~< -r ;..^-' J ,? I I I rn\t ii.;''/. •.•-'•-•. •i j. ' •! ; r ' I © 1 i 1 1 ' ' I 'I! ' . • ' ! . ' i! ,i 11, ! ! ! !•„ !i;! ;:i nil!; li i: !i::!:!;!: l'> ['•_"-, "* ' ' : " - ' / • • - / l i " i : Xp'V"V [•*'•'•*-{ L''^''"^ 1 ''' ,._ . *. -;—-•--• T - ; * r|—•"-•• • •_JT~r~i~*"» ~~****/r'~~~~~'/ "TT -"*~~ t *"* I-'1 '< h •!•: i ' i i'! ! ' ! : i . 'ijijj j - . : ; . ! ! , , : : : ' , '*". ". ."i" --' '.7*^ x"^: \ " • --' "' •'\ ". '-'-5^ ',, "^ !*.'" .-• ^v_ _^*3^^ 'S.:^.^JSS^Slvi^§^.-^:;Hi>": I"i:ix% i^Vx-' '_.jj*" ] : ' ]• ?';'; "^t"" 'X^'..'_'; : JLL'^_:. '^iK.-!1..'JlL.HL!_^i.^ <^' •:.!-::- :^ ' i - ' (7 ": '-0- ^•L.v'^-'-V : ••:,'^^H^^ALLL "!:L.l ' ' '• '"• " ui.JllS5k Id i! ili �DM* ROUTING AND TRANSMTTTAL SUP office symbol, room number. ^- r/po»« Initials Date DO NOT use this form as a RECORD of approvals, concurrences, disposals, clearances, and similar actions FROM: (Name, org. symbol, Agency/Post) Room No.—Bldg. Phone No. 5041-102 OPTIONAL FORM 41 (Rev. 7-76) Prescribed by GSA FPMR (41 CFR} 101-11.206 �xLE SUMMARY Lo c a t i on o f. F lie; Box^ Number: -^fppf File Originator; f ^ j-f File Numbar; fJJf\ File Titles ,'ly Synopsis Document Title/ Flag/ Folio Nc Reference JAssociatec Papers ! K COS MJOLA r- IWWCJ/ Ow^O* K �<s^! ky-r w t FJL.JE_ SUMMARY x,. 1 LOGation of Fi1e: / Box Number; jST&T ^p> IS" File Originator; \ft~f File Number; A^//T File Title: i *TP ^ Af5Ol Document Title/ Flag/ Folio Nd Reference I. Synopsis JAssociatec . J_Paper^ ^ "1! O bi| ' HORSESHOE. � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 076 Folder The folder containing the original item. 1961 Series The series number of the original item. Series III Subseries IV Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Minarik, Charles E. Jack B. Shumate Nadir G. Vakili Fred H. Tschirley Date A point or period of time associated with an event in the lifecycle of the resource July 12 1969 Title A name given to the resource Herbicide Damage to Rubber and Fruit Trees in Cambodia Subject The topic of the resource herbicide application ecological impact ecological recovery ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 040 Folder The folder containing the original item. 0931 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Norman, Colin Source A related resource from which the described resource is derived Science Date A point or period of time associated with an event in the lifecycle of the resource March 11 1983 Title A name given to the resource Vietnam's Herbicide Legacy Subject The topic of the resource congenital birth defects ecological recovery Southeast Asia ao_seriesIII Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 027 Folder The folder containing the original item. 0396 Series The series number of the original item. Series III Subseries I Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Source A related resource from which the described resource is derived Pesticide Abstracts Date A point or period of time associated with an event in the lifecycle of the resource 1977 Title A name given to the resource Abstract: Anonymous. La CEE per Seveso. [The EEC for Seveso.]; Abstract: Hay, A. Dioxin Damage. Subject The topic of the resource ecological recovery dioxin ao_seriesIII https://www.nal.usda.gov/exhibits/speccoll/files/original/6bfe6fdacd32f0945eaefd87eb976309.pdf 13fd457ac6429cc18aaf38a6d8709bd3 PDF Text Text Item ID Number: Author Corporate Author 00093 Bartlcson, Fred D. U.S. Air Force, Air Force Systems Command, Air Force Armament Laboratory, Environics Office, Eclin AFB A Survey of Trees on a Herbicide Treated Test Area, Eglin AFB, Florida: Final Report: Juno to August 1974 Journal/Book Title Year 1974 Month/Day November Color Number of (manes 42 Descpipton Notes pr °Ject soeeoi 01 Friday, December 08, 2000 Page 93 of 106 �TECHNICAL REPORT AFATL-TR-74-190 A SURVEY OF TREES ON £ I. : < A HERBICIDE TREATED TEST AREA, : EGLIN AFB, FLORIDA ENVIRONICS OFFICE NOVEMBER 1974 FINAL REPORT: June to August 1974 this report limitation istribution requests for Vrmament Florida AIR FORCE ARMAMENT L A B O R A T O R Y AIR FORCE SYSTEMS COMMAND • UNITED STATES AIR FORCE EGLIN AIR FORCE BASE, FLORIDA �UNCLASSIFIED S E C U R I T Y C L A S S I F I C A T I O N OF THIS P A G E (When Datu Entervtl) READ INSTRUCTIONS BEFORE COMPLETING; FORM REPORT DOCUMENTATION F'AGE 1. R E P O R T NUMDER 2 GOVT A C C E S S I O N NO 3. R E C I P I E N T ' S C A T A L O G NUMBER AFATL-TR-74-190 4. T I T L E (and Subtitle) 5. TYPE OF REPORT & PERIOD COVERED Final Report A SURVEY OF TREES ON A HERBICIDE TREATED TEST AREA, F.GLIN AFB, FLORIDA - August 1974 6. P E R F O R M I N G ORG. R E P O R T N U M B E R 7. AUTHORS.) B. CONTRACT OR G R A N T NUMBERf.iJ Fred 1). Bartlcson, Jr, Lt Col, IJSAF Don I). Harrison Charles [. Miller 9. 10. P R O G R A M ELEMENT. PROJECT. TASK AREA 4 WORK UNIT NUMBERS P E R F O R M I N G O R G A N I Z A T I O N NAME A N D A D D R E S S Environics Office (DLV) Air Force Armament Laboratory Eglin Air Force Base, Florida 32542 II. Project 50660101 12. R E P O R T D A T E CONTROLLING OFFICE NAME AND ADDRESS Air Force Armament Laboratory Air Force Systems Command November 1974 13- NUMBER OF P A G E S 15. S E C U R I T Y CLASS, (of this report) Eglin Air Force Base, Florida 32542 14. 43 M O N I T O R I N G A G E N C Y N A M E ft ADDRESSHf dttlcmil from Controlling O/ficoJ. UNCLASSIFIED IS*. 6. DECLASSIFICATION DOWNGRADING SCHEDULE D I S T R I B U T I O N S T A T E M E N T (of this Report) Distribution limited to U. S. Government agencies only; this report, documents test and evaluation; distribution limitation applied November 1974. Other requests for this document must bo referred to the Air Force Armament Laboratory (DLV), Eglin Air Force Base, Florida 32542. 7. D I S T R I B U T I O N S T A T E M E N T (of the abstract entared in Dior* 20, if different from B. liaport) S U P P L E M E N T A R Y NOTES Available in DDC. 9 KEY W O R D S (Continue an reverse sidu if nece.iaary mid Identify by block number) Herbicide Treated Areas Tree Survey Ecological Recovery 0. A B S T R A C T {Continue on reverse iic/e If necent,ary and Irliintilv by block number) A survey was made of trees growing on the 1 square mile instrumented test grid of Test Area C-52A, Eglin Air Force Base Reservation, Florida. This area had previously been subjected to land clearing operations and heavy herbicide deposition. The active herbicide ingredients have disappeared, hut there were still many large areas devoid of young trees. The absence of trees in these areas was apparently due to heavy herbicide deposition which prevented regeneration from roots of previous trees and the lack of soil moisture, which has retarded the germination of seeds. The lack, of soil moisture was principally attributed DD , F O R M73 1473 JAN EDITION OF 1 NOV 65 IS OBSOLETE UNCLASSIFIED S E C U R I T Y C L A S S I F I C A T I O N OF THIS P A G E flWi.-n Data Ent-rcd', �UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGEfWian Data Entered) Item 20 Continued: to the previous removal of ground cover and consequent drying effects of the wind. The areas with the most trees were generally outside of the herbicide spray aircraft primary flightpaths and were in more moist soil. Young oak trees, sprouting from roots, were predominant on the tost area and were in contrast to the surrounding pine forest. Additional studies were recommended to evaluate future vegetative succession. SECURITY CLASSIFICATION OF THIS PAGEfVWien Dale Entered) �PREFACE This technical report Is the result of research conducted by the Air Force Armament Laboratory from June 197'1 to August 1974 under Air Force lixploratory Development Project 50660101. Information on the physical characteristics and past history of Test Area C-52A wa.s obtained from APATL-TR-74-12, Ecological Studies on a Hcrbiculc-liquipmcnt Test Area ('TA C-52A), Eglin AFB Reservation, Florida, by Captain Alvin L. Young ('January 1974). This technical report has been reviewed and is approved. \JOXA. FARMF.R Chief, Hnvironics Office I (The reverse of this page is blank) ��TABLF: OF CONTENTS Section I [I III IV V Appendix A Page INTRODUCTION 5 DESCRIPTION Ol7 T/\ C-52A 6 SURVEY METHODS 11 RESULTS AND DISiiUSStON 13 CONCLUSIONS AND RECOMMENDATIONS 23 A SURVEY OF TREES ON A HERBICIDE TREATED AREA OI: EGLIN AFB, FLORIDA - TEST AREA C-52A (JUNE-AUGUST 197.1) 25 (The reverse of this pa»e is blank) ��SECTION T INTRODUCTION Between June and August 1974. a survey was made of the trees growing on a 1 square mile instrumented test grid in the center of Test Area C-52A (TA C-52A), liglin Air Force Base Reservation, Florida. This test area received massive quantities of military herbicides during the period 1962 to 1970 while aerial dissemination equipment was being tested. Prior to this period, the area had been bulldozed and cleared of vegetation in order to make it a useful test range. It has also been burned several times by controlled burning and by wild fire. The objective of the survey was to provide baseline data for studying the ecological recovery and reforestation of an area subjected to land clearing operations, mowing, and extensive herbicide applications. �SECTION II UI-SCRTl'TION OP TA C-52A TA C-52A is a man-made, grassy plain that covers approximately 3 square miles (Figure 1). It is surrounded by a dense forest stand that is dominated by sand pine (Pinus £jjiusn_ (Cngelm) VasoyJ but that also includes longleaf pine (P inu s pal us t r i s Mill), turkey oak ('Qucrcus J.aeyijS_ Walt), and live oak (Qucrcus yijrgirviana Mill) . The instrumented "rid used for herbicide equipment, testing is subdivided into 400-by 400-foot sections by permanent markers (Figure 2). This grid is occupied mainly by broomsedgc (And r op o go n v i r g i n icus L.)i switcligrass (Panicurn virgatum L.), and low growing grasses and" herbs. The soils of the test grid arc predominantly well drained, acid sands of the Lakeland association and include Lakeland, Chipley, and Rutlcdgc sand series (Figure 3). A small shallow pond is located just south of marker F-7 and an intermittent pond is located northeast of marker G-13. The average annual rainfall on the area is approximately 60 inches, and the average temperature is approximately 65°F. Herbicide spray, aircraft flightpaths, and herbicide quantities are shown in Figure 4. There was no way to determine the exact quantity of herbicide deposited on each of the sample plots. Deposition levels would vary considerably, depending on existing meteorological and flight conditions, as well as on herbicide discharge rate. Figure 4 shows the quantity of herbicide delivered on the instrumented grid and the quantity deposited on a noninstrumented grid (Grid 1) immediately south of the surveyed area. Grid 1 received nearly 1,000 pounds of herbicide per acre between 1962 and 1964, and undoubtedly, some fallout occurred on the test, plots of the 1 square mile gr id. Young (Reference 1) lias provided a thorough description of the area including vegetation, animal life, climatology and soils, us well as the history of the use of the test area and herbicide deposition levels. Reference I . A. I,. Young: lico I og i ca L_Stud i es o n a 1 ler b ic id c^ I! qu ipine n t_ Tos t Area (TA C-52A) F.glin AF~B Reservation',"Worlda".''" M;AYL"-:fK~7<l -12~"TTr~Torce Armament Laboratory, l i g l i n AFB~, F l o r i d a . January 1974 ( U n c l a s s i f i e d ) . �/ " .— -—* -—•••"JTT-"-"— f-- < ^ INACTIVE 0 SPOTTING TOWER ^•} CONTROL ' SONTRAVES ^ v^iS ~--~ =—= ASKANIA BLDG PAVED ROAD = CLAY ROAD = === SAND ROAD O TOWER INTEHANGE BOUNDARY LINE .- .» RANSE SATE a BARBED Wl'_ -' •' Z_J t'ifcfc-oe0 oob- = v m & •» •^ -r j a Figure 1. Map of Test Area C-52A, Eglin AFB Reservation, Florida �I 2 3 4 5 6 A O O O O O B O O O O O 7 T 8 CO D O O O F O O O O O O O L O O O II 12 13 14 O O O O O O O O O o o o o O O O O o o o O O O O o O O O O O O O O N O O O O O o o O O O O TOWER a O O o O o O o O o O o — 400 FEET O O O O O o o o o o o o o o o O O M O o O O O O O O o O O O J O K O O 10 o o o o o o o o o o o O H O O E O G O 9 O O O O O O O o O O O O O O O 0 O O O O SOO O o O O O O O 1000 O O o O O o O O O O O o o o o O O O O O O O O O O O O O O O O 1500 200O GRAPHIC SCALE-FEET •Figure 2. Location of the Permanent Sampling Stations on the One" Square M i l e Grid �r*. .w« -. jj, .*- 'V, '>V FM^HBPl -A** .H?*w«^jf|' '•".:',>"' • ' ..}•• 'Is.'?'*' . ft*V.T- -.iSafs2-.f v\;: /.-• '^:; -;^-.-:-;^ l^ l W l-'igurc 3. S o i l Types and Water on the One Square Mile drid on Test Area C-52A.' A I.AKi;i,ANI) SAND (, KUTLl-Dfil: SAND B C I K I M J - Y SAND - W/V1T;R �TOTAL NUMBER OF POUNDS OF HERBICIDE Years 1, -1-L) 19(>6-19':j .14,010 l9GG-l<rt) 2,784 1961-1960 33,021) 2 ^ - 1 , 5-T 38,1.">0 l'j_clorara Cacodylpc Acid Arsenic !,:>(»! 12,595 1,889 75.7 1 ,OJ'.l IIM 35,026 -- S7,lo(, 87,1 'Center of r i i g h t p u r h s uurins! r h i - j period w,-is located .•ipproxiir.iitcly l,Pni) feet south of n u r k c r \-7. • S o l i . l l.inos - M.i.ior I'l i ^ h r p a t i i s ' I'a.shcd Lines - M i n o r F l l c h t p i i t h s 6 Tigurc 4. 7 Y 8 3 10 11 12 13 14 FlLghtpaths of Herbicide Spray Aircraft. (Major fIightpaths used arc shown with solid lines and minor by broken .lines.) 10 �SUCTION L E T SURVEY MliTIlOHS The tree survey was made by sampling each of the 169 sections (400 by K)0 feet) of the test grid. Five sample plots were taken at predetermined locations in each of the sections. These plots (SO by 50 feet.) were located 50 feet diagonally from the permanent markers at each corner of the section and at the center of the section. When the intended sample area was interrupted by a road, the plots were shifted 50 feet in the direction shown by the arrows i.n Figure 5. Within each plot, the species and height (to the nearest foot) of each tree were recorded (Appendix A). Oaks (Qucrcus spp) were frequently found growing in dense clusters. In such cases, all shoots emerging from the ground that were over 6 inches in height were counted as separate trees. 11 �50' I X 50' Figure 5. Location of the Five Sample Plots within each of the Grid Sections. (Arrows indicate direction plots were novcd if roads interfered.) 12 �SUCTION IV ROSUI.TS AND DISCUSSION A total of 5,155 trees was counted in the 845 sample plots on the 1 square mile grid of TA C-52A, representing an average of 126.9 trees per acre. The average could be misleading, however, because 66 per cent of the sample plots contained no trees. 1'igurc 8 shows the distribution of trees. The species present were dispersed in patterns over the grid due to largely unknown reasons, and the dominant species in one area might be scarce in another area. However, over the entire grid, the dominant species were live oak (Qucrcus yjj^ipiajw Mill) and turkey oak (Qucrcus lacvis Walt). Five other species of oaks (Qucrcus spp), three species of pines (Pinus spp), and the common persimmon (Diospyros virginiana L.) were also found in the sample plots. The number and heights of these trees are shown in Table 1. Although not observed in any of the plots, one cedar (Junipcrus silicicola (Small) Bailey) was observed on the grid. The combined effects of land clearing, fire, and herbicide application on the survey area were quite pronounced. The denudation of the area resulted in scquelai, such as loss of soil moisture and blowing sand, that continued to retard ecological recovery (Figure 6). A large part of the area had not recovered sufficiently to permit natural reforestation, particularly in the southern one-third and in parts of the northeast corner of the 1 square mile grid. These areas were quite arid and sandy but did contain a few widely scattered small trees even in sections where no trees were observed in the sample plots. The mean height for the 5,155 trees counted was less than 2 feet. Only 41 of these had a height over 6 feet (I'igurc 7), the tallest being 11 feet. Most of the trees were oaks found in small but dense clusters originating from the roots of previous trees. Trees starting from seeds, such as pines, persimmons, and single oaks, were relatively sparse, but their presence indicated the area was recovering. Although the data were not statistically analyzed due to lack of precise information on actual herbicide deposition, there docs appear to be some correlation between previous spray aircraft fIIghtpaths and plots with no trees. There also appears to be some correlation between the presence oF trees and the more moist Chiplcy ard Rut ledge sands, ns well as the proximity to the two major clay roads which cross the grid. 13 �I'iguro 6. Darren Area Sliowing Kffccts of Blowin* Sand. ° L4 �TABLE 1. TREES TOTAL NO. FREQUENCY AND HEIGHT OF TREES IN SAMPLE PLOTS ON TA C-52A 2 1 3 HEIGHTS IN FEET 4 5 6 7 8 ... 11 MEAN HEIGHT STANHARO DEVIATION TALLEST TREE, FT Live Oak Quercus virginiana (Mill ) 3682 1886 1048 485 187 56 16 1 3 1.79 1.03 8 Turkey Oak Quercus laevis (Walt) 1064 370 357 181 104 36 10 2 4 2.18 1.23 8 Sand Post Oak Quercus margaretta (Ash) 188 126 38 18 5 1 1.49 .82 5 Persimmon Diospyros virginiana (L.) 117 54 40 17 4 2 1.80 .93 5 Blue Jack Oak Quercus incana Bartr. 53 13 24 7 4 2 2.38 1.35 6 Sand Pine Pinus clausa (Engelra.) Vasey 21 5 12 3 1 2.00 .77 4 Water Oak Quercus nigra L. 20 10 6 4 1.70 .80 3 Longleaf Pine Pinus palustris (Mill ) 4 3 Laurel Oak Quercus laurifolia (Michx.) 3 Chapman Oak Quercus chapmanii (Sarg.) 2 Slash Pine Pinus eliottii (Engelra.) 1 TOTALS S1S5 3 3.50 5.00 11 1 2.33 .58 3 2 3.00 3 2.00 2 1 2 1 2467 1528 718 305 97 29 3 7 1 1 .87 1 .09 11 �Turkey Oak Live 0;ik Blue Jack Oak Long l,caf Pino 12 13 14 Tigure 7. Distribution of Observed Trees at. Least 6 Feet High on-'R C-52A. 16 �I Plots Without Trees Ll N Plots With Trees N 0 2 3 4 5 6 7 J 8 9 10 12 13 I'ijjurc 8. Map Showing Arnas in Which Trees Were round. 17 14 �Photographs of typical areas on the grid arc shown in Figures 9 to 12 and of the surrounding cleared areas are shown in Figures 13 to 16. As can he seen, young trees were well developed in the adjacent clearing on all sides except to the south where massive herbicide applications were made between 1962 and 1961. This area, called Grid 1, consisted of a 2,000-by 2,000-foot test area centered approximately 1,000 feet south of marker N-7. Although not a part of the current study, Grid 1 was surveyed on foot and only 6 trees were observed. Four of the trees were sand pines and the other two were longleaf pines. The dominance of small oaks on the 1 square mile grid contrasted markedly with the clear dominance of sand pine around the border of the clearing. Oaks also predominated in most: of the cleared area surrounding the 1 square mile grid, except to the south (on and around Grid 1), where there were only a few small pines. This lack of trees on Grid 1 appeared to be more related to the previous heavy herbicide deposition than to lack of soil moisture, except for the area adjacent to the 1 square mile grid, which was extremely arid and sandy. Agcrton and Crews (Reference 2) have shown that the residual herbicide has, for all practical purposes, disappeared. They were able to grow sensitive agronomic crops in the most arid section 300 feet south of marker 0-7. These crops required considerable extra water and were not as healthy as controls, but showed no herbicide damage. In general, it appears that land clearing and herbicide application killed the trees in the clearing and also some of the oaks along the tree line. With the disappearance of the active ingredients of the herbicides and cessation of land clearing operations, trees are reappearing, hut mainly from the roots of previous trees. Natural rcseeding has been slow due to the distances from other mature trees and the lack of soil moisture necessary for seed germination. Strong winds in this large open area contribute to the drying of the soil and probably keep most small seeds from settling in the barren areas. Reference 2. Agcrton, 15. M. Mild R. C. Crews: A Study of Agronomic Plants Grown on Herbicide Contaminated So Us. AFATL- l'R-75~-N~, Air Force Armament Laboratory, January 1975 (Unclassified). 18 �*"V, ',«.•»>$'"'WSvijV,' iV'jr*.', . F- *'Vj- &?-^'>;«# \ • ' ;'• V •:.,,,; „, ,,V>', ' ,-r.r.' .•.'.,....'. "- ' v, • : .,.. .•:,:.";;•;*^,^ ""• ;,; V* ;i; vi'-i:.''*;i. v't':' '.' ; ••- *.pi*" " '••'.•.'.; *•'?;'!:'v.^ '. ;,'/'.'''• *f* •«'.:,;?'»'.; v^./'V".:••'•.• .'•• • :> .••,.. • • • " - . ' r^?.^>|«^.i: 'f^'i^^,^^,;^:^ ^.v^;;;^,^^^;^ >w.- r-'-^V; ^^:^*)s^iiiMfe:^fe^ Figure 9. Northern Section .* ' •'•.",,:~»>-*.";'«. •.. »•.» ' ' ^ .&• !#; •/* Figure 10. Southwestern Section �• '•'.'' • ' H •.-; ;'•'i'. : ; . •." V., • A i i ;. « • f •W i -'"''. . ' A•^' ' »". * •. ^ f '[ 'ijj" X ••-:,.sJ '^vf- V ' 4 Figure 11. Western Section V ">'•* V'Hr '•'/ J, .^^^^^.^^ • "^yi^i^ v< .1.&M%&L .1 , •?. " * *'•« vnflATI F i g u r e 12. Southeastern Section <r.* �l : igure 13. North of Instrumented Grid ' ; • ' • :,;, - P t -\FM« , i. , K. . " •L** ' >* :- - r^ , F : i n u r e 1-1. liast of I n s t r u m e n t e d (Irid 2'I t f *'S �Figure 15. West of Instrumented Grid Figure 16. South of Instrumented Grid, Overlooking Grid 1 22 �SUCTION V CONCLUSIONS AND RECOMMENDATIONS The 1 square mile instrumented test grid of Test Area C-52A has previously received massive and repeated applications of military herbicide and has been subjected to land clearing operations. These operations resulted in the destruction of trees and much of the other vegetation on the instrumented grid and parts of the adjacent areas. There have been no recent requirements for land clearing operations, and chemical analyses and bioassays have revealed that the active herbicide ingredients have disappeared. The area appeared to be in a normal stage of vegetative succession. The ecological recovery was obviously being retarded by a lack of soil moisture and by the constant movement of soil by the wind. Both of these factors were probably induced by the previous repeated destruction of vegetative ground cover and trees. Grasses had started to infiltrate even the most arid sections of the test grid. This, together with the reappearance of small trees in certain parts of the area, should accelerate the recovery. In contrast to the surrounding pine forest, the trees of the cleared area were principally oaks. The vast majority of these probably sprouted from roots that, survived the various stresses rather than from seeds brought into the area. In the southern sections, which received the most herbicide, it appeared that even the roots of the trees were destroyed. Trees in these sections were sparse even in the more moist areas and apparently originated from seeds. The results of this study indicate that the lack of trees on parts of the test grid is directly related to previous herbicide applications and that succession is generally niorc rapid in the more moist areas. Additional surveys should bo nude in future years to study the pattern of succession in this unique test area. Appendix A contains data collected in this survey, which can be used for comparison in future studies on the vegetative succession of TA C-52A. 23 (The reverse of tliis page is blank) ��APPENDIX A A SURVEY OF TREES ON A HERBICIDE TREATED TEST AREA OF EGLIN AFB, FLORIDA - TEST AREA C-52A (JUNE-AUGUST 1974) Height t.o the nearest foot and frequency of trees arc recorded for each species of tree observed in the sample plots. Plots arc numbered 1 through 5 (sec Figure 3). Sections were identified using the letters and numbers on the instrumented grid beginning with Section A-l in the northeast corner (sec Figure 2). Plots not. listed had no trees over 6 inches in height. Abbreviations used for species arc as follows: 1JJO - Blue Jack Oak - Qucrcus incana Bartr. TKO - Turkey Oak - Qucrcus lacyis (Walt) LVO - Live Oak - Qucrcus virginiana (Mill) CIIO - Chapman Oak - Qucrcus_ chapmanii (Sarg.) SPO - Sand Post Oak - O^ucrcu^ mra-garctta, (Ash) MO - Water Oak - Qucrcus nigra L. LRO - Laurel Oak - Quorcus laurifolia (Michx.) SNP - Sand Pine - Pinus cljuisia (Engelm.) Vascy LLP - Longleaf 1'Lnc - Pinus paIustr_is_ (Mill) SUP - Slash Pine - Pinus c l l i o t t i i (lingelm.) PSM - Persimmon - Diospr-os v i r g i n i a n a ( L . ) 25 �HEIGHT AND FRliQUr-NCY SECTION PLOT SPI-CTES 1' 2' 3' 4' 5' A-l -1 TKO LVO 2 71 0 32 1 13 0 1 LVO TKO LVO SPO TKO LVO 0 0 23 5 4 0 0 0 12 0 2 2 1 1 8 1 5 2 3 2 1 6' 7' 8' TOTAL 3 117 A-l A-l -2 -3 A-l -4 A-l -5 TKO 1 3 0 2 1 7 A-2 -1 TKO 10 7 5 1 1 24 A-2 -3 TKO LVO 9 8 3 3 4 1 1 A-2 -5 TKO LVO 1 0 2 0 3 1 A-3 -3 LVO 0 2 0 1 3 A-3 -4 TKO BJO LVO 0 0 5 1 0 1 0 1 2 1 5 2 1 3 43 6 15 6 17 12 6 1 A-4 -1 SNP 1 1 A-4 -4 TKO 1 1 A-7 -1 LLP 1 1 A-9 -3 TKO 2 2 A-9 -5 TKO 0 A- 10 -1 PSM 1 A-10 -3 TKO 1 0 A- 10 -4 TKO 1 3 4 A-10 -5 TKO 6 1 7 L 0 I 1 1 26 4 6 �I IR TGI IT AND FREQUENCY SrCTTON PLOT SPECIES 1' 2' 3' 4' 5' 6' 7' 8' TOTAL A- 11 TKO 3 A-ll -2 TKO SPO 4 6 0 1 1 5 7 A-ll -3 TKO 1 2 1 4 A- 11 -4 TKO SPO 4 2 I A-12 -1 TKO 1 A-12 -3 PSM SNP 6 1 1 7 1 A-12 -4 WRO 0 1 1 A-12 -5 SPO 1 A- 13 -3 TKO 0 1 1 A-13 ; -1 -4 TKO PSM 1 1 1 1 2 TKO B.JO L\rO 5 0 1 4 0 0 3 0 1 TKO LVO 0 3 2 0 1 2 4 TKO IA'0 4 8 2 5 4 6 17 B-l B-l B-l -1 -2 -3 3 5 2 1 1 2 0 B-l -4 LVO TKO 19 3 17 2 14 3 -5 LVO TKO 0 1 1 1 0 1 mo 0 0 0 TKO LVO 7 9 2 8 3 2 15 1 2 1 16 3 B-l 1 0 B-2 _2 27 66 11 1 3 1 1 * 9 22 �HEIGHT AND FREQUENCY SECTION PLOT SPECIES r 2' 3' 41 5' 2 1 2 B-2 -3 TKO I,VO 3 1 4 4 4 1 B-2 -4 LVO WO 3 0 3 1 -5 TKO LVO 0 0 2 0 I 0 B-3 -1 LVO TKO 17 4 3 2 2 LVO TKO 1 1 4 0 LVO SPO TKO 0 8 0 3 0 1 1 1 7' 6 I B-2 51 B-3 B-3 -2 -3 8' TOTAL 15 7 12 2 1 0 J. 1 1 1 7 1 20 8 2 0 L 1 1 1 8 1 8 5 B-4 -1 TKO IA'0 1 2 2 0 5 1 U-4 -3 BJO TKO SPO 0 1 7 1 0 fj 1 2 2 B-4 -4 LVO PSM 6 2 6 1 3 B-4 -5 TKO 3 0 ] 4 B-5 -J LRO 0 0 1 1 H-5 -4 LVO 1 0 2 B-5 -f> PSM 1 1 B-6 -1 SNP PSM 0 8 0 8 B-10 -2 PSM 0 i 1 B-ll -1 TKO 0 3 3 9 4 2 3 14 1 1 16 3 4 2 0 28 1 1 16 �HEIGHT ANf) FREQUENCY SECTION PLOT SPECIES 1' 2' 3' 1 1 2 81 1 4' 5' 6' 7' TOTAL B-ll -2 SNP TKO SPO 0 4 0 R-ll -3 SPO 1 B-ll -5 TKO 0 2 2 B-12 -1 TKO 4 1 5 B-12 -2 TKO SPO SNP 0 0 0 2 2 1 5 3 10 7 2 5 2 1 3 0 5 3 1 1 B-L2 -3 TKO SPO 5 4 B-12 -4 SPO PSM 1 0 1 1 1 2 B-L2 -5 TKO 1 1 B-13 -1 TKO 1 6 B-13 -2 PSM 0 1 1 B-13 -3 TKO PSM 2 0 5 I 7 1 B-13 -4 TKO PSM SPO o 4. 0 1 3 3 L 0 3 1 1 12 3 3 1 1 5 B-13 -5 TKO 1 C-l -I TKO WHO LVO 0 6 10 1 L 4 0 1 3 1 TKO WHO I.VO 0 1 0 0 0 1 1 2 1 1 1 10 1,VO TKO 0 0 0 1 1 1 1 3 C-l C-l -2 -4 1 1 29 1 2 7 19 �HEIGHT AND FREQUENCY PLOT SPLCIES C-l -5 C-2 -2 SUCTION 1' 2' 3« LVO 0 2 2 LVO TKO WRO 3 1 0 1 5' 1 0 I C-2 -3 LVO TKO 9 0 0 ] 3 C-2 -4 TKO LVO PSM 2 4 2 2 5 3 6 4' 1 6' 7' 8' TOTAL 5 5 1 1 1 13 1 7 16 2 1 C-3 -I TKO WRO 3 0 4 0 0 1 1 C-3 -2 LVO 1 1 0 6 C-3 -3 TKO 2 2 C-3 -4 LVO TKO 5 0 10 0 8 1 1 9 4 5 0 0 1 20 1 C-4 -1 LVO 3 4 7 C-4 -2 TKO LVO 2 5 1 3 3 8 C-4 -3 LVO TKO 8 1 9 3 C-5 -1 LVO TKO SPO 7 2 4 3 3 1 10 6 4 2 5 C-f. -2 LVO 0 I I C-5 -3 LVO TKO 1 0 8 1 3 0 C-5 -4 LLP 1 C-5 -5 LVO TKO 19 1 22 4 1 1 13 2 1 15 2 3 1 30 3 1 40 5 �ULilG'lT AND FKliQUl-NCY SECTION C-6 PLOT SPliCII-S 1' 2' -1 LVO TKO SPO 5 v3 4 1 1 1 4' 5' 6' 1 3' 1 7' 8' TOTAL 8 3 6 14 C-6 -3 LVO 9 5 C-6 -4 I.VO TKO 22 3 19 3 4 1 10 1 1 C-6 -5 LVO SPO 44 10 19 2 9 1 5 1 C-7 -3 LVO 4 0 0 1 5 C-7 -5 TKO 0 0 0 • 1 1 C-8 -4 TKO PSM 0 0 0 2 1 1 1 3 C-ll -3 TKO PSM 2 0 0 1 2 1 56 8 1 79 13 C-12 -2 TKO 9 2 11 C-12 -5 TKO 0 2 2 C-13 -1 TKO LVO 1 0 2 3 3 3 C-13 -2 TKO PSM 0 0 1 0 1 C-13 -5 TKO 0 0 0 !)-! -I TKO SPO 0 3 0 ] -.3 LVO 0 1 D-l -4 TKO 0 2 2 D-l -5 TKO SNP 0 0 0 1 0 0 1 D-l 1 1 0 1 1 1 4 1 31 4 1 1 1 �HP.IGIIT AND FRHQUI-NCY PLOT SPr.CIliS L' 2' 3' 4' 5' 6' "7 1 / 8' D-2 -3 TKO 0 2 2 3 1 0 0 1 D-2 -4 SNP LVO 0 1 1 2 D-2 -5 TKO 8 12 3 2 D-3 -5 [,VO PSM 6 0 2 1 2 2 12 1 D-3 -4 LVO TKO 4 0 1 1 -) 4. 1 1 8 3 SF.CTION TOTAL 9 1 3 1 D-3 -5 SNP -3 TKO IA'0 SNP 4 1 0 4 2 0 1 26 1 D-4 I 1 2 2 1 L 1 2 17 3 1 D-4 -4 LVO 9 19 5 0 0 1 D-5 -2 LVO TKO 45 2 13 1 3 2 3 2 4 3 D-5 -4 TKO 2 3 0 0 0 1 D-5 -5 TKO LVO 1 10 0 2 1 1 2 2 n-6 -1 LVO 65 46 24 .14 l)-6 _2 TKO LVO 2 A 2 3 1 0 2 I 7 8 l)-6 -3 TKO SPO LVO 4 ] 3 f> 0 2 3 .1 12 5 4 T ^ 34 1 72 7 6 4 15 1 150 l)-6 -4 LVO 5 3 8 !)-() -5 TKO 2 1 3 l)-7 -L TKO LVO _L11Q 2 6 Jl 2 3 J. 4 1 • 10 1 32 �I Hi TGI IT AND FREQUENCY PLOT SPRCII-S 1' 2' 3' 4' 5' l)-7 -2 LVO WRO PSM 15 3 3 13 2 12 1 11 1 l) 7 ' -4 PSM TKO 2 2 0 0 I D-7 -5 TKO LVO 13 6 5 1 1 . l)-8 -01 LVO 4 5 1 10 D-8 -04 LVO 3 0 2 5 D-9 -02 PSM 0 1 1 U-9 -05 LVO 23 9 5 37 D-10 -04 I.VO 6 1 4 11 D-10 -05 SPO 8 2 2 12 l)-ll -3 TKO 1 0 L D-ll -4 TKO PSM 2 2 1 1 SLCTION 6 i D-12 -4 TKO SUP 1 0 2 1 -2 LVO PSM 1 4 4 1 0 1 TKO LVO B.JO 5 5 0 13 2 4 1 1 -1 1 TOTAL 53 6 3 20 7 3 2 4 2 I--I 8' 3 2 1)-L3 1 7' 3 2 1 0 6' 5 1 2 2 0 1 7 9 1 20 7 6 !•-! -2 TKO LVO 5 6 1 5 E-l -3 TKO LVO A r> 4 0 1 1 9 6 I--L -4 TKO 7 4 4 15 6 11 33 �HEIGHT AND FREQUENCY 1' 2' 31 PLOT SPECIES K-2 -1 LVO SPO TKO 2 1 1 1 4 I- -2 -2 TKO LVO 2 15 1 20 0 2 E-2 -3 LVO 0 0 -4 TKO LVO 0 5 1 2 3 1 5' 7' 8' 1 E-2 4' 1 SUCTION' 6' TOTAL 4 5 1 L 1 0 1 5 38 1 2 2 6 11 ] E-2 -5 TKO 5 2 I- -3 -1 TKO LVO SPO 5 1 7 3 3 1 1 2 1 E-3 -4 TKO 3 1 1 3 8 E-3 -5 TKO 4 0 2 1 7 E-4 -1 LVO 6 5 2 0 E-4 -3 LVO 4 0 1 Ii-4 -4 TKO 2 2 1 1 F.-4 -5 LVO 14 33 11 10 E-5 -1 TKO LVO 4 8 4 13 3 4 E-5 -2 TKO 0 1 1 1 E-5 -3 TKO LVO 3 10 1 7 2 6 1 .1 1 1 2 1 1 E-5 -4 LVO JO 8 K-5 -5 LVO 0 -1 TKO 2 1 9 6 9 1 14 5 6 4 72 11 25 3 1 0 8 27 1 1 r-6 7 22 1 2 34 . 5 �HEIGHT AND FREQUENCY PLOT SPECIES 1' 2' 3' 4' 5" E-6 -3 r,vo 9 4 2 J 1 li-6 -4 CIIO 0 0 2 li-7 -1 LVO TKO 3 1 2 0 1 1 1 E-7 _2 LVO TKO 54 2 12 2 17 3 7 2 H-7 -5 TKO 0 0 0 ] K-8 -1 LVO TKO 65 3 18 4 11 1 1 0 5 SECTION 61 7' 8' TOTAL 17 2 1:-<J -3 LVO 6 1 Ii-9 -4 SNP 0 -2 LVO 1 0 n-io -1 LVO 0 -5 PSM 0 1 0 -1 TKO LVO 1'SM 5 0 0 0 2 I 0 0 1 1 R-ii 93 9 1 1 n-io 3 1 n-io 7 2 2 95 9 12 1 0 1 1 3 1 2 1 6 1 l* I E-ii -5 LVO 13 10 K-12 -3 B.TO TKO 1 I 2 5 3 6 H-12 -4 LVO SNP L 0 2 1 3 1 fi-12 -5 LVO 11 6 n-i3 -4 TKO SPO 0 i I F-I -1 TKO LVO 0 0 4 0 25 8 25 1 1 2 0 35 2 2 ] 9 2 �IlETfiin 1 AND FREQUENCY L' 2' 3' TKO 0 7 0 1 1 9 -3 TKO 0 1 1 0 1 3 1 ; -1 -4 TKO 1 F-2 -2 TKO LVO SNI' 3 2 0 5 3 1 F-2 -3 I.VO TKO 1 6 1 F-2 -4 TKO 1 P-3 -1 TKO LVO 1 6 2 13 2 7 1 3 PLOT SPLCIliS r-i -2 F-] SECTION 4' 5' 6' 7' 8' TOTAL I 1 2 1 10 7 1 2 6 1 6 31 2 F-3 -2 TKO 4 3 ? 1 10 F-3 -3 TKO LVO 0 5 2 0 1 3 5 P-3 -5 TKO 2 0 3 F-4 -1 TKO 1 2 1 0 0 F-4 _2 I.VO TKO 10 5 10 1 3 5 3 2 L LVO TKO 10 0 5 I I 0 1 0 0 PSM TKO 2 2 0 4 2 L 1 4 8 F-4 F-4 -3 -4 5 I 5 26 14 17 2 L F-4 -5 TKO 0 0 L 1 2 F-5 -1 LVO TKO 1 0 3 6 I 1 1 ! 6 8 I-1 -5 -2 TKO I.VO 9 JO 18 5 '1 3 1 I 36 1 32 19 # �III! TGI IT AND FREQUENCY SUCTION F-5 PLOT SPIICI1-S -3 TKO PSM LRO 1' 2' 3' 4' 5' 9 3 0 4 3 0 2 3 3 6' 7' 8' 18 3 1 1 F-5 -A TKO I.VO 2 53 12 L F-5 -5 I.VO TKO PSM 3 4 3 2 0 1 2 1 3 TOTAL 20 54 F-6 -3 LVO (-> 1 4 2 F-6 -'1 TKO IA'0 BJO 4 30 0 1 8 0 3 6 1 1 2 0 1 9 5 8 3 0 0 1 17 9 46 2 F-6 -5 LVO 72 24 9 8 F-7 -4 LVO 44 24 16 1 85 F-7 -5 LVO 53 25 9 1 88 F-8 -1 LVO 161 75 24 3 263 F-8 _2 LVO 1.4 11 5 I' -8 -3 LVO 37 4 7 2 2 F-8 -4 LVO 13 5 5 3 1 F-9 -O rj I.VO 12 9 2 23 F-10 -1. SPO 3 0 1 4 F-ll -2 LVO 29 39 2 70 F-il -'1 LVO TKO 25 L 6 0 3 0 7 F-ll -5 LVO SNP 85 0 20 1 F-12 -1 LVO (> 6 5 0 1 128 30 1 1 55 27 34 2 112 1 12 37 �Ill-IGI IT AND FRPQUP.NCY /| i SP.CTION PLOT SPr.CIP.S 1' 2' F-12 -2 LVO 4 2 1 G-l -1 TKO 3 2 1 G-l -4 TKO LVO 4 31 7 18 6 13 2 3 1 G-2 -1 LVO 1 1 1 1 1 G-4 -L TKO LVO 4 4 19 1 4 1 2 1 0 1 G-5 -1 TKO 0 2 0 0 0 0 1 | G-5 1 -2 TKO 0 G-6 : -1 TKO LVO 3 6 G-6 i -2 LVO 1'SM -16 0 3' 5' 6' 7' 8' TOTAL 1 8 6 1 21 65 5 30 7 0 1 3 L 1 3 1 1 l 17 f 6 1 1 2 8 30 16 1 5 9 52 6 1 2 i 6 G-6 -3 LVO 4 0 2 G-6 -4 LVO 7 0 3 ' G-7 -1 LVO 15 13 5 2 35 G-7 -2 LVO 19 20 6 I 46 G-8 -1 LVO SPO 10 8 6 2 3 1 20 10 • G-8 -.3 LVO RJO 5 3 5 1. 0 1 11 4 G-8 -4 LVO 24 8 f> 4 G-9 -3 SNP 0 0 1 1 G-10 -3 LVO SNP 0 0 0 1 3 3 1 G-10 -5 SPO 4 1 10 1 42 . 38 5 i �lir.TCIIT AND FKl-OJIliNCY SI-.CTION PLOT fi-11 -» srrrii:s 2' L' 3' _r r, 1 I.VO RJO I.LP 71 2 0 S3 3 0 14 2 0 2 0 0 2 6' 2 0 7' 0 8' 0 9' 0 10' 0 11' L'OTAL 1 138 9 I G-1L - ;> I.VO 15 8 9 G-12 -3 . L.VO fi 2 3 10 Ci-12 -.1 I.VO 27 12 3 42 G-J3 -t PSM 0 3 U-13 -5 PSM TKO LVO 3 r> •i 0 2 0 1 1 L TKO SPO I.VO 9 s <) 1 2 TKO Sl'O SNP 2 7 1 6 ll-l ll-l -1 -1 r, 7 2 3 "t 34 3 0 1 4 8 6 0 29 8 14 3 0 2 3 1 11 10 1 II-J -3 TKO •7 0 3 T 11-4 -1 I.VO TKO 2 0 3 0 '1 2 1 II-. 1 _2 I'KO I.VO 2 8 4 3 2 0 1 2 18 0 0 1 2 11-7 •t 11.10 1 0 0 M-7 -;•> IUO 6 3 _2 I.VO 0 0 0 11-10 _2 SPO (> 2 1 11-11 -1 I.VO 1 3 11-11 _2 I.VO SNP 10 0 T 1 10 2 1 II-'J 7 10 1 1 9 4 0 0 I 13 I �HEIGHT AND FRIiQUrNCY PLOT spncins 1' 2' 11-11 -3 LVO PSM 8 0 5 0 11-12 -1 SNP LLP LVO 0 0 34 1 1 17 SLCTTON 3' 4' 6' 5' 7' 8' TOTAL 1 1 14 1 2 1 1 53 11-12 -2 LVO 2 2 M-12 -3 LVO 5 2 11-12 -4 SPN 0 1 11-13 -1 TKO PSM LVO SPO LLP 1 5 5 3 1 1 9 5 0 2 ! 3 ', 1 4 1 SPO TKO LVO 4 4 3 2 1 2 1 1 3 1 0 11-13 -2 4 1 2 10 1 2 16 17 5 I ; 10 4 9 1 11-13 -5 TKO 2 0 1 J-l -5 TKO 0 0 0 L ,1-1 -4 TKO 0 2 3 2 J-7 -5 TKO 1 4 5 J-10 -I LVO L 1 2 J-10 -3 LVO TKO 0 I 0 0 1 1 J-10 -r> TKO 1 '1 0 1 .1-11 -5 LVO TKO 9 3 3 4 3 1 0 J-12 -2 SPO SNP 0 1 0 1 3 1 I 8 1 2 , . 6 1 16 8 • 40 1 L �lir.ir.IIT AND l-'Ul-qULNCY SliCTION PLOT spi:.cn:s .J-12 -3 M ?' 3' Sl'O I.VO I>SM y 0 3 2 •r I 0 0 !>' (>' 7' 8' 9' 10' 11' TOTALS •1 10 3 6 1 11 ,1-12 -I I.VO y ,1-12 -S TKO 3 1 .1-13 -3 TKO PSM 7 3 -1 1 1 12 4 ,1-13 -I TKO 3 2 I 6 .l-l.i -S TKO 2 K-] -1 LVO 8 f> 3 K-l -1 RJO TKO 0 0 '! 1 11 1 K-ll -1 1,VO 0 0 1 1 K-l 1 ••> FA'O 2 K-l 2 -1 I.VO •1 0 2 l.-l -1 TKO S 2 0 1 1 7 I-l _ •» TKO 1 2 J 0 1 5 l.-l -3 TKO 0 1 I.-L -I TKO 1 0 0 1 M-l -1 11.10 TKO 0 L 0 0 I TKO 0 0 0 1 166 52'.) 717 307 N-L -1 TOTAL 4 2 2 18 3 12 1 2 0 2 1 1 1 !).r> 30 3 41 (The n-vcrso of t.his page is lilunk) / L 5155 ��INITIAL DISTRIBUTION AFSC/DLW AFSC/SDWM 2 1 AFSC/DPSL Tech Lib 1 USAP/SAMI 2 ASD/F.NYS (Mr Hartley) DDC 1 12 AFATL/DL AFATL/DLOSL AFATL/DLV 1 3 50 ADTC/CSV (Maj Conrad) USDA (Mr Kuhns), Forest Service 2 25 USAFA/DFLS AFLC/DS AUL (AUL/LSF.-70-239) 10 2 1 4950 Test Wing/TIIM' Ogdcn ALC/MMNOP 1 2 AFWL/LR APSC/VN 2 2 Edgcwood Arscnal/SAREA-TS-L Edgcwood Arsenal/SARP.A-CL-V Vegetation Control Div (SAREA-CL-V) Army Material Command (AMCKD-WB/AFSC-SDWC) 1 1. 2 1 OOAMA/MMNO 1 SAAMA/SFQT i UKDA, Pesticide Coordinator 2 USDA, Agriculture Environmental Quality Institute 2 USAF Environmental Health Lab (APLC) 2 USAF (PREV) 2 43 (Tlie reverse: of this piigfi is blank) � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 010 Folder The folder containing the original item. 0093 Series The series number of the original item. Series II Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Bartleson, Fred D. Don D. Harrison Charles I. Miller Description An account of the resource <strong>Corporate Author: </strong>U.S. Air Force, Air Force Systems Command, Air Force Armament Laboratory, Environics Office, Eglin AFB Date A point or period of time associated with an event in the lifecycle of the resource 1974-11-01 Title A name given to the resource A Survey of Trees on a Herbicide Treated Test Area, Eglin AFB, Florida: Final Report: June to August 1974 Subject The topic of the resource tree survey ecological recovery https://www.nal.usda.gov/exhibits/speccoll/files/original/0bd7eefae477111446ce3989d7aafa1f.pdf 0f2840d2e9d4ceed9d9dcf177f8dfb71 PDF Text Text Item ID Number: Author 00092 Blackman, Geoffrey E. Corporate Author National Academy of Sciences. National Research Council Report/ArtlClO TltlB The Effects of Herbicides in South Vietnam: Part B, Working Papers, February 1974: Persistence and Disappearance of Herbicides in Tropical Soils Journal/Book Title Year 1974 Month/Day February Color Numbor of Images 60 DeSCPlptOn NOteS P 4 missing Friday. December 08, 2000 Page 92 of 106 �. > £s-T~ '—\4' (O \ M 5(7/1 The Effects of Herbicides in South Vietnam PART B: WORKING PAPERS FEBRUARY 1974 Persistence and Disappearance of Herbicides in Tropical Soils GEOFFREY E. BLACKMAN, JOHN D. FRYER. ANTON LANG, and MICHAEL NEWTON NATIONAL ACADEMY OF SCIENCES �THE EFFECTS OF HERBICIDES IN SOUTH VIETNAM * "PART B: WORKING PAPERS FEBRUARY Persistence and Disappearance of Herbicides in Tropical Soils GEOFFREY E. BLACKMAN, JOHN D. FRYER, ANTON LAJJG, AND MICHAEL NEWTON NATIONAL ACADEMY OF SCIENCES - NATIONAL RESEARCH COUNCIL WASHINGTON, D.C. 20Ul8 �Persistence and Disappearance of Herbicides in Tropical Soils GEOFFREY E. BLACKMAN, JOHN D. FRYER, ANTON LANG, AND MICHAEL NEWTONa SCOPE OF WORK A very obvious and legitimate question poses itself when an extraneous material has been introduced into the environment: how long will this material persist, or how fast will'it disappear? Disappearance in this case means loss of its characteristic activity either in its original form or in the form of derivative(s). For the military herbicide operations in South Vietnam (SVN) this question is particularly obvious and urgent. Herbicides have been used in those operations at levels roughly five to ten times higher than in normal agricultural practice, and some areas were sprayed twice and more often, sometimes within a relatively short time. Where effects of defoliation persist, as in the mangrove forests, is it because the herbicides are still active, or because of other changes induced by the herbicides, even though the latter themselves may have disappeared? In addition, claims have been made—in articles on the effects of the use of herbicides in the Vietnam war, in news reports, and * Professor Blackman, a member of the Committee on the Effects of Herbicides in Vietnam, is Professor Emeritus at the Department of Forestry, Oxford University, Oxford, England 0X1 3RB. Mr. Fryer, a member of the Committee on the Effects of Herbicides in Vietnam, is Director of the Weed Research Organization, Agricultural Research Council, Begbroke Hill, Sandy *~ Lane, Yarnton, Oxford, England 0X5 1PF. Dr. Lang, Chairman of the Committee on the Effects of Herbicides in Vietnam, is Director of the MSU/AEC Plant Research Laboratory, Michigan State University, East Lansing, Michigan U882U. Dr. Newton, a consultant to the Committee on the Effects of Herbicides in Vietnam, is Associate Professor of Forest Ecology, School of Forestry, Oregon State University, Corvallis, Oregon 97331- �elsewhere—that these compounds have "poisoned" the soil, rendering large areas incapable of supporting either indigenous or crop vegetation. Some of these reports convey the impression that vast parts of SVN are barren and will remain so for unknown but extemsive periods of time. The term "ecocide," i.e., destruction of the plant and animal community on a large scale and in an irreversible manner, has.been used. The Committee therefore considered soil studies on persistence i and disappearance of herbicides among its essential tasks. This task was approached in two ways. First, on our forays into different parts of the country we collected soil samples in areas that had been sprayed operationally with herbicides during the Vietnam war. As far as possible, emphasis was placed on sites that had received high total doses of herbicides, since it seemed that the prospects of finding measurable residues would be highest at such locations. However, this collecting activity was greatly limited by security problems. Thus, only one inland forest site could be sampled, and it had received only two sprays. The total number of samples from operationally-sprayed areas was U8. Most of the samples were subdivided into two or three parts and almost all of them were analyzed for two different herbicides, and some for three; hence, the total number of analyses was about 200. The Committee also collected some water samples from a river in the heavilysprayed Rung-Sat Special Zone mangrove area. Second, the Committee conducted a number of experiments in which the soil surface was sprayed with herbicides at a known rate equivalent to that used in a single operational spray mission. The �disappearance of the compound was then followed by sequential tests over a period of about 150 to 2f>0 days. El The reason for doing these experiments was that vhen the Committee started its work, one and a half years had elapsed since the termination of major herbicide operations. ,• It was thus too late to observe the early stages of herbicide behavior in the soil. However, a knowledge of these early stages is very important if valid conclusions are to be reached about the course of the disappearance of the herbicides. In addition, it appears that where crops had been destroyed by herbicides, farmers were sometimes hesitant to replant, being afraid that the new crops would also be killed or damaged. The Committee was on several occasions asked when replanting would be safe. About 1000 soil samples were analyzed for herbicide content during this phase of the Committee's work. In addition, a series of biological tests to evaluate the rate of disappearance of herbicides was undertaken. All herbicide experiments in SVW were conducted with the authorization of the GVN and, where appropriate, of tlu: proper local authorities. The Committee also conducted an experiment in which two strips of mangrove, each UOO ft (100 m) long by :2 ft (30 m) wide and totalling .0 less than 2 acres, were sprayed by helicopter with Agent Orange and Agent White, respectively. The objectives were to study the early responses of the plants, to determine differences in sensitivity, and to investigate the behavior of the herbicides in tl-.e soil under conditions comparable to those of wartime herbicide operations (or, more exactly, to follow up the consequences of the first herbicide application to vegetation). However, this experiment failed; the sprayed vegetation exhibited only minimal symptoms of damage and th .se had almost completely disappeared seven months later. The reasons are not entirely clear. The herbicide batches used were the same as those f.iiat proved very effective when sprayed by hand on soil. Most probably, :.hc equipment, which had not been in use for quit<_- a long time, was not functioning properly and did not deliver the specified amount of herbicide. No analyses for herbicides were done from these plots. �work. Biological determination was used primarily in the experiments with agricultural crops and soils because here the advantage of this method, as just mentioned, is particularly evident. If a plant does not show measurable effects six months after application of a herbicide to the soil, it can be concluded that this particular plant, if resown, will remain undamaged in future plantings, provided cultural and environmental conditions are not appreciably changed.- , The test plants that were chosen for the Committee's experiments were rice and other crop plants of considerable present or potential value in SVN and other tropical countries. Biological measurements of herbicide effects on mangrove seedlings were also carried out. Serial plantings were made in order to determine how long herbicides have direct adverse effects on mangrove seedlings, and also to obtain some information on conditions for reestablishment of the mangrove. The first chemical determinations were carried out by the Weed Research Organization, Yarnton, Oxford, England. Subsequently, the analytical work was conducted under a subcontract with the Huntingdon Research Centre, Huntingdon, U.K., an organization with considerable experience and an excellent reputation for this kind of work. The analyses were made mainly for 2,4,5-T, one of tha compounds in Agent Orange, and for picloram, one of the compounds in Agent White, because all experience indicates that these are more stable than 2,^-D (which is present in both Orange and White). 2,U-H was determined only in selected samples, usually those with a high content of either of the other two compounds. The analyses were carried out by means of electron capture gas chromatography. The methods used were the most up-to-date standard �residue procedures available and have beer proved in several different laboratories. For picloram a basic extraction followed by esterification with diazomethane (McKone and Cotterill, unpublished) was used; for 2,U,5-T the residues were extracted into an organic solvent and then the n-butyl ester ,« (McKone and Hance 1972) was the preferred derivative. Following routine procedure in herbicide work, all results are given as acid equivalents, disregarding the moiety of the molecule that forms the ester.' The results for soils are expressed as Ib/acre of soil surface, i.e.., as if all herbicide in a sample (or subsample) was deposited on the surface of the soil. Water samples are reported in parts per million (ppm). Values preceded by a < mean that no herbicide could be detected at this level of sensitivity. It will be seen from the results that the limit of detection varied to some extent from one batch of samples to another. This was because of slight changes in the sensitivity of the electron capture detector over a period of time, and in a few cases also because of varying amounts of material available, (if these amounts drop below a certain limit, the sensitivity of the analytical methods decreases.) The accuracy of the results was ensured, however, by the inclusion of some analytical standards with each set of samples. To check the reliability of the determinations, a random selection of samples with high, medium, and low herbicide levels was analyzed by the Gulf South Research Institute, New Iberia, Louisiana: the comparative results are shown in Table I. It can be seen that at low concentrations, near the detection limit, the agreement between the two determinations was generally good; at higher concentrations, the values found for the two forest soils by GSII were considerably lower than those of HRC. In our evaluations we used the HRC data, since their results for control tests (samples taken immediately after spraying) were— �1 I Table I. 1 Comparative determinations of 2,4,5-T and picloram in soil samples by Huntingdor Research Center and Gulf South Research Institute. •T , Data in ppm. < • below this detection limit. ster ND - not detected. 2,4,5-T Picloram e e (or ported HRC GSRI 1 2.99 3.293 0.44 0.260 1.28 1.114 0.342 0.102 0.59 ' 0.510 0.047 0.032 0.26 0.096 0.04 0.012 0.06 0.049 0.004 0.003 0.03 .0.016 <0.004 ND 1 0.03 0.005 <0.002 ND 2 ' Mangrove (Vung-Tau.SVN) GSRI 3 4 5 6 gardlng ' •' HRC 2 Soil . Sample No. 0.013* 0.005 <0.002 ND 0.005 <0.001 ND 0.005 <0.001 ND •.e Mangrove (Rung Sat) results !S to 3 <0.02 a 4 r rtain 1 2 3.16 0.412 0.402 0.115 0.58 0.245 0.060 0.041 0.02 0.016 0.003 ND 1 . 8.09 0.332 1.265 0.132 1.13 0.079 0.03 0.003 a Forest (Bnn-Me-Thuot,SVU) <().005 3 sctron 0.02 0.011 0.005 T 1 i Forest (Los Banos, Philippines) t of ulf are Section it higher insidersince 5) were — •Analyzed by Weed Research Organization Note: The samples for 2,4,5-T and for picloram are not always identical ND �with a single exception—very close to the theoretical values. (The GSR! analyses did not include such control tests.) Soil Sampling Soil sampling was done in two ways. Surface samples were collected mostly with the aid of metal (iron) cans, 5 in. (12.5 cm) high and of the same diameter, which were pushed into the soi;: and then extracted with the aid of a spade. This procedure was mainly used with mangrove soils, since they are soft enough to permit complete insertion of the can. Deeper samples, which will be called cores, were collected with soil samplers specially constructed by the Weed Research Organization. Two different but similar samplers were used, both consisting of a metal tube with sharpened bottom edges, either 2 in. (5 cm) or 1.75 in. (k.k cm) wide and either 36 in. (90 cm) or 30 in. (75 cm) long. Both samplers were provided with strong, interchangeable metal caps: one plastic-covered to minimize damage when driving the sampler into the soil, the other provided with handles to extract it again. There were also removable split inside liners for extracting the cores, but these proved to be of limited value and the cores were usually pushed out of the sampler tube with a metal rod with a disk at one end. When muddy soil (mangrove) was collected, an adjustable air vent at the upper end of the sampler tube was left open while inserting the sampler into the soil, to permit escape of air. The vent was closed, or the upper opening of the tube simply plugged with a rubber mallet, when the sampler was extracted, thus generating a vacuum that helped keep the soil in the sampler tube. Sometimes, a metal tube with a metal rod inside was pushed into the mud next to the sampler and 8 �the rod then withdrawn; this permitted air to penetrate to the end of the sampler, relieving a vacuum and facilitating the extraction of the sampler. In many cases, both with hard forest soils and with soft man- grove mud, the sampling proved an arduous and time-consuming task, and . * despite all precautions the contained cores were often considerably shorter than the length of the sampler because part of the core slipped out of the sampler and/or because the friction between the soil and the wall of the sampler tube either caused the core to compact or prevented the soil from entering the tube beyond a certain point. Wherever soil samples were collected, some control samples were taken from areas that had not been exposed to herbicides. These controls served to ascertain whether the soil contained natural materials interfering with the determination of the herbicides. If this was so, the analytical procedures were modified so as to exclude such sources of error. Criteria used for choosing the control sites were: information on herbicide missions in the area (printouts from the HERBS tape and, where available, information from local, military personnel); condition of the vegetation; and information from the local population (village and district officials, and farmers or woodcutters). In the mangrove, where sprayed areas exhibit pronounced damage and often complete kill of the mangrove trees, identification of control sites was not difficult. Good local information faciliated location of the forest sites at Pran Burl, Thailand, and Cau Muoi-Mot, SVN, as well. In other locations, the identification was a good deal less reliable, and it appearr, that some of the control sites had been exposed to herbicide, too. �The surface samples were stored in the cans, which were closed •with their lids. The cores were in most cases divided into two or three parts and placed either into double polyethylene bags or, more commonly, into plastic jars with airtight screw caps. In the case of mangrove soils,.j/hich are highly anaerobic (i.e., lacking in air and particularly in oxygen), care was taken to fill cans and jars to the rim and to tape the lids of the metal cans with masking tape, thus reducing exposure to air, which might cause changes in the soil and thus also affect herbicides still present in it. The samples from SVN and the Philippines were stored in a deep freezer and shipped for analysis in frozen condition. All effort was made to complete these safety procedures as rapidly as possible, and in most cases the samples were placed in the deep freezer on the evening of the day of sampling or on the nextday. However, particularly in the earlier part of the Committee's work, this was not always possible and samples occasionally had to remain unfrozen for as long as one week. In some cases, it was possible to keep them part of this time in a refrigerator, Water samples were kept in plastic containers in the dark to prevent breakdown of herbicides by light. Some formalin was also added to prevent decompostion by microorgejiisms. HERBICIDE DETERMINATIONS IN SOILS AND WATER FROM DEFOLIATED SITES Sites The sites that have been subjected to herbicide sprays in connection with the Vietnam war and from which the Committee took soil samples are listed in Table II. Two were in an area in Thailand that had been 10 �Table II. Location, herbicide spraying history, and soil sampling information for land sites that had received herbicides during military operation. Location - (SVN, unless otherwise noted) Date Forest, Pran Buri, Thailand: June 1965 herbicide spray test site. Plot 28 Spray history Agent Orange + picloram Amount Date No. & type of samples 9.1 Ib/acre 0.5 " Sep 30,1971 8 cores (2 ea. from 4 sites) ca. 16-26 in., divided in upper organic part (ca. 6 in.) and remainder Oct 1,1971 9B6 Ib/acre Purple 497 '" Pink 310 n Orange 128 " Dicamba Cacodylic acid (aBlus) 57 " Picloram 20 " = total of ca. 840 Ib 2,4-D; ca. 960 Ib 2,4,5-T; 128 Lb dicamba; 57 Ib cacodylic acid, 20 Ib picloram per acre Calibration Grid, Pran Buri. Thailand 1964-65 Crop land: dump site near Chieu-Lieu Hamlet TanDong -Hiep Village. Di-An Distr., Bien-Hoa Prov. Dec 1, 1968 1000 gal. Orange dumped on circular path from 1800 ft. forest: Cau Muoi-Mot strongpoint, ca.8 mi. (12 tan! north Dong-Xoai Village, Don-Luan Distr., Phuoc— Long Prov. Dec 1, 1968 White Apr 12,1969 Orange Oct 8, 1971 6 cores, ca. 26-32 in... 3 ea. from a bare (Nos. 1-3) and from a grass-covered (Nos. 4-6) area and 2 from an area supposedly outside the grid (Nn. 7.8): all divided into 3 equal sections (T-*top, M=middle. B^botton) 4 cores., ca. 28-35 in. divided into 3 approx. equal sections (T,M,B) 3 gal/acre Oct 16, 1971 4 cores, ca. 33-34 in., 3 " divided into 3 equal sections (T,M,B) �Table II, continued Location - SVN (Unless otherwise noted) Spray history Agent Date a ' Amount Date Mangrove, Rung Sat Special Zone Site tl No. s type of samples r 1965 1966 1967 1968 Aug 4, 1968 Aug 7 1968 ftug 3, 1968 ftug 9,1968 Aug 18, 1968 Mar 1, Jan 6, Nov 11, Aug 3, Orange Orange Orange White Orange Blue Orange White 3 gal/acre n 3 n 3 n 3 ii 3 n 3 ii 3 ii 3 H 3 Oct 9, 1971 3 surface samples. depth not determined, = RS-1 through -3 Mar 9, 1972 2 cores, 36 in., divided into 3 equal parts (T,M,B) = RS-4 and -5 Aug 31,1972 6 surface samples (5 in,) and 6 cores (ca. 30 in.) from same sampling sites divided into 2 equal sections (T,B) = RS-6 through -11 Site tS Aug 31,1972 6 samples same as Site #1 31 Aug 72 -- RS-12 through -17 S,T,B Site #6 Site §7 Site 18 Aug 31,1972 Orange a minimum of 86 Ib 2,4-D; 79 Ib 2,4,5-T; • 3 Ib piclcrara; 9 Ib cacodylic acid per acres compare text. One sample each, same as Site 11, Mar 9, 1972 (T,M,B) -. RS-18 through -20 �Table II, continued. Location - SVR (Unless otherwise noted) Date Mangrove, Ca-Mau Peninsula: Ca. 9-45 yd both sides of airstrip at Nam-Can village, Kan-Can Distr., AnXuyen Prov.' Ca. 3 mi. north-northeast of Nam-Can Naval Base, west bank of Kinh-Ngang canal Spray history Agent July 1968 Orange Sep 20-21, 1962 Purple Mar 11, 1970 White Apr 8, 1970 Orange Apr 21,1970 White Site appears to be on boundary of White and Orange sprays Amount Date No. & Type of Samples Oct 1 , 1971 3 samples each consisting of several cores, ca. 36 in., which had been divided into 3 parts;" 6 in.-6 in.remainder (T-M-B)j plus one sample 12 in. only: T and M 3 gal/acre 3 3 3 Oct 12, 1971 3 samples as in Ca-Mau Peninsula, above The figures are the depth of the hole. The length of the core was often considerably less, due to compacting and/or friction preventing the soil from entering the sampler. This was particularly marked with many mangrove samples. Agent Pink c - 60% 2,4,5=T-n=butyl ester 40% 2,4,5-T-isobutyl ester Dicamba =3,6 dichloro-o-anisic acid (controls certain phenoxy tolerant broadleaf weeds and brush species) �used for extensive trials with different herbicides in 1964-65, prior to large-scale use in SVN. No herbicide symptoms were seen on native plants, crops, or weeds. Samples were collected from one of the few trial plots that could still be definitely located (Plot No. 28), and from the center of the so-called Calibration Grid. The latter is an old rifle range at the Pran Buri Training Center, and all treatments that were used in the individual trials had been sprayed over this site. The direction of the sorties was at varying angles according to wind, but all intersected in a central area that, at the time of the Committee's visit, still stood out clearly because of several large patches of completely bare soil or very restricted vegetation, mostly grasses (imperata and others). This site had received truly formidable quantities of some herbicides, e.g., 70 times more 2,4,5-T and almost as much more 2,U-D as delivered on one regular herbicide mission with Agent Orange (or lUo times as much 2,4-D as on one Agent White mission). In SVN, the Committee was able to take soil samples in a so-called dump area, i.e., an area where, because of engine or other trouble, a plane delivering herbicides had released (dumped) the entire load over a relatively small area. The sampling site, which was in an area presently under crops (at sampling time, mainly peanuts), was originally located from the report of the pilot of the dumping plane and was subsequently verified by interviews with district and village officials and with villagers. It was definitely within the perimenter of the dump, although probably nearer its edge than its center. At the time of the Committee's visits, many dead trees—mostly fruit trees—could be seen, either still standing or, more frequently, felled and cut for firewood. �Some fruit trets had dead branches that may have been the result of herbicide damage, although the trees had produced new growth and were bearing some fruit. Some tall, unidentified tress looked, quite normal, however, suggesting that the dose of herbicide had not been excessively high as compared to regular herbicide missions. (The dump was made from a height of 1800 ft or 5^0 m, as compared to the '150 ft or 6(3 m of the regular defoliation mission.) , The one inland forest site that could be sampled in SVN had been subjected to one Orange and one White mission. The area had been heavily disturbed by long-term human activity; only a thin stand of large trees and much old bamboo were present, and the trees were either dead or exhibited clear herbicide damage.. In contrast, a relatively substantial number of samples were collected on several trips to the central part of the Rung-Sat Special Zone, in a mangrove area that has received more herbicide sprays than any other region in SVW. One site, our #1, had been within the recorded flight lines of nine missions and received six times as much 2,U,5-T and seven times as much 2,H-D as a single Agent Orange mission, or about 1^4times the amount of 2,U-D as a single Agent White mission. Moreover, these are minimum values; no less than 24 other missions had passed near the site between January 1966 and September 1966, and the site had almost certainly been reached by additional herbicide:--if not directly, then by drift. The level of herbicide exposure of the other, sampling sites in the Rung-Sat mangrove was undoubtedly similar. In the mangrove of the Ja-Mau Peninsula, the southernmost tip of the country, samples could be taken from two sites. One of these, situated close to the Nam-Can 15 �Naval Base, bad been hand-sprayed with Agent Orange. Datc(s) and amounts are not known, but since some of the mangrove plants showed regeneration, the level was probably not higher and perhaps somewhat lower than from an aircraft spray. The second site, on the Kinh-Ngang Canal about 3 miles (k.8 km) northeast from the first, had received a spray with Agent Purple, a precursor of Orange, in 1962, and two White and one Orange sprays in March-April 1970. The sampled area was entirely devoid of live mangrove trees but was covered in parts by a creeping grass (Paspalum sp.). As far as possible, sampling was done according to some pattern aimed at a uniform distribution over the accessible area that also included different parts of it. For example, in some of the mangrove sites completely bare areas were examined along with areas covered with grass (mai Faspalum vaginatum) and bearing some mangrove seedlings. Sometimes, however, e.g., in the Cau Muoi-Mot forest, the accessible area was so small that sampling had to be done at random. Water samples were taken on two occasions in the lower part of the main shipping channel to Saigon that runs through the Rung-Sat Special Zone, beginning at our land site RS #1 and going south on the Dang-Xay, Mu-Na , and Dong-Tranh Rivers.. Some control samples were collected in a small channel near our experimental sites in the mangrove of Chi-Linh near Vung-Tau (see below). The sites of the second Rung-Sat samplings, made on August 31, 1972, are shown in Figure IV C-5, Section IV, Mangrove Forests, Part A of the Report on the Effects of Herbicides in South Vietnam. No precise record was kept of the first sampling occasion in the Rung-Sat, but the area was similar to that of the second occasion. All samples were 16 �taken at outgoing tide and near the water surface. Results; Soil Samples Results of the soil analyses are summarized in Table III. Substantial levels of picloram and 2,4,5-T, sufficient to prevent growth or . 4 to cause serious malformations in many broadleaf plants, were present six years after application in some of the soil samples from the Calibration t Grid in Pran Burl, Thailand. Picloram was found throughout the length of the cores, but except in one (out of six) the concentrations in the bottom third (20 to 30 in. or 50 to 75 cm) were low. • 2,^,5-T was found in the top and middle thirds (top, 0 to 10 in. or 0 to 25 cm; middle, 10 to 20 in. or 25 to 50 cm) in one sample, and in the top third in three samples; none was found in the bottom thirds. Residues of both 2,U,5-T and piclorara were also found in some soil samples from the Rung-Sat mangrove. Sample Site #5 (samples RS #12-1?) seemed to contain 2,U,5-T consistently, particularly in the subsurface (below about 15 in. l3& cm] and to about 30 In. 175 cml). No detectable amounts of picloram were found at this site to the depth that could be reached with the soil samplers. Some samples at Site #1 (samples RS #1-11) contained 2,4,5-T or picloram, and picloram but no detectable 2,U,5-T was present in the single samples from .Sites #6, #7, and #Q (samples RS #18-20). In Sites #1 and #2, presence or absence of vegetation--including some mangrove seedlings—at the sampling sites seemingly was not linked with the variation of herbicide content .in the so:ll. All herbicide levels found in the Rung-Sat mangrove soil are below those that can be expected 17 �Table III. Herbicide residues in th^ soil samples of Table II, in Ib/acre. not sampled or analyze 1. = below detection lirut. S/T = surface samples or top portions of cores, B = bolton portions of cores. ?,4-D Site S/T Forest, Eran 'Purl, Plot 28 1-8 Calibration Orid, Pran liuri 1 2 3 5 6 7 8 Bump Site, Di-An Distr. 1-4 Bulked S/T' ' D B - Sample No. - f. 0.07 --0.03 .<;0.06 <ro.o6 -.'0.07 ^ 0.08 V, ^ 0.04b - £0.005a -^0.005a -; 0.06 -0.03 1.35 C.96 0.03 0.23 0.06 ''0.03 <0.o6 0.09 <0.04 C •'0.005 ^0.005 - <0.005d - " A A a ^0.006 o.oi 0.004 _ - <o.ooi <: o.ooi < 0.001^ < 0.001^ £ 0 . 001 <0.008 v. 0.035 <" 0.036 0.079 v.0.031 0.032 0.032 0.002 <0.006 v' 0.004 < 0.004 *0.004 < 0.004 •* 0.004 < 0.004 <: o.oo4 < o.oo4 C 0.004 < 0.004 <o.oo6 *' 0.004 ^0.004 * 0.00k ^ 0.004 <0.004 < 0.004 0.003 < 0.004 < 0.004 < 0.004 < 0.004 < 0.004 c 0.004 0.011 --0.007 0.007 0.003 0.179 0.023 0.057 0.109 0.1146 0.037 <.o.oo4 < o.oo4 0.006 f* . A < 0.005 ' <o.oo5 -•0.03-. OU0.03 <0.02fl 0.003 <ro.oo3 0.008 1.19 0.24 :0.03 . <:o.ooia <o.ooia 1.09 -.'0.03 -- 0.06 < 0.06 -'.0.06 Picloram S/T B 1.03 0.43 0.72 0.60 ^0.03 <' 0.06 <LC,03 Forest, Cau-Muoi-Mot 1-4 _ < 0.006 _ 0.010^ Mangrove, Site #1 RS-1 Rung-Sat RS-2 0.013° - <0.005d _ RS-3 «. 0.007 RS-4 - < 0.006 £0.007 RS-5 *0.04 <0.04 <:0.04 _ RS-6 0.09 RS-7 '.0.04 -10.04 <0.02 RS-8 0.19 RS-9 £ 0.0k 0.21 RS-10 •:0.04 - <0.03 RS-11 >• 0.04 0.015 Site- #2 RS-12 ^0.04 - <: o.oi RS-13 j' Q 0^.- 0.04 RS-14 0.24 _ 0.02 RS-15 j' O Qij <o.oi RS-16 ^ 0.04 - 0.015 RS-17 Site #6 RS-18 - 0.007 <. 0.007 ^0.007 Site #7 RS-19 - 0.007 ••^0.007 <0.004 - < 0.006 Site #8 RS-?0 / 0.007 Mangrove, Nam-Can Airstrip 1-3 Canal KinhHeane 1-3 | A CO. 02 - <o.oor <ro.ooiQ rt A ^Values in ppm since surface area of sample not known and therefore computation of Ib/acre rate not possible e 4 samples Only part of samples samples, bulied 4 samples, bulJced b 3 C 16 �to cause damage to crops in normal agricultural practice. No herbicide residues could be detected in the samples from Pran Buri Site #28-, the dump site in Di-An District, the forest near Cau Muoi Mot, and the two mangrove sites in the Ca-Mau Peninsula. The failure to find detectable herbicide in the second Ca-Mau site (at the KLnhNgang Canal) is interesting insofar as this site had been sprayed relatively late in the war, one and a half years before our sampling. Results; Water Samples Water samples from the lower part of the main shipping channel to Saigon were analyzed for picloram, the most persistent of the herbicides used for military purposes in SVN. Suspended sediment—mostly soil—was separated from the water by filtration, and the two fractions were analyzed separately. As Table IV shows, no herbicide was found in the filtered water, but the sediment of four out of eight samples contained amounts ranging from about 0.07 to 0.03 parts per billion (ppb) of water and from about 2.2 to 0.8 ppm of dry weight of sediment. If all the herbicide in the sediment were to become available in the water, the levels would, be far below the concentrations known to affect even the most sensitive species, but if only the sediments are considered, the levels are somewhat higher than those found in the Rung-Sat soil (maximum 0.01 Ib/acre = 0.05 ppm). Herbicide in. water is usually associated with suspended material if such is present, and turbid water may contain more herbicide than clear wa+.er, but the relatively high pic3oran content in the Rung-Sat sediment is somewhat unexpected. �Table IV. Analyses for plcloram in water samples from the Rung Sat. Values In ppra. ND = not determined Location and water sampling aite no. Concentration in filtered water Concentration in sediment Computed for water Computed for sediment (dry weight Vung-Taui No. 2 ND <0. 00002 <0.11 4 5 6 7 6 9 10 ND <0. 00003 <0. 00002 <0.00002 0.000043 0.000036 0.000066 0.000029 <0.17 <0.24 <0.50 1.26 1.06 2.24 0.77 Rung Sat, No. No. No. No. No. No. No. ND ND <0,0001 <0.0001 <0.0001 <0.0001 20 �EARLY STAGES OF HERBICIDE BEHAVIOR IN SOIL 'UNDER TROPICAL CONDITIONS This section summarizes the Committee's own experimentation on persistence and disappearance of herbicides fn certain tropical soils. Agricultural Sites -* In all experiments with agricultural lands, the soil, previously cleared of any vegetation, was sprayed with either Agent Orange or Agent White at the rates of ( ) three gal/acre (the rate used on most military l spray missions, (2) one gal/acre, and (3) one-third gal/acre. The agents, as manufactured, are much too concentrated to permit accurate dosage for the relatively very small plots treated in all our experiments, and therefore they were diluted. In the case of Agent Orange, which is insoluble in water, an aqueous 'emulsion was made with the aid of special emulsifiers. Agent White is water soluble, and the necessary additional amounts of water were added directly to the conmercial preparation. The application was by means of a carefully calibrated backpack sprayer and a spray boom designed to ensure a uniform pattern of distribution (constructed by the Weed Research Organization). All spraying was carried out by one and the same person (except in the mangrove microplot experiment). Comparable plots were left unsprayed as controls. None of the plots had been treated with herbicides before our experiments. Beginning some weeks after the herbicide application and at regular intervals thereafter, selected crops were sown or planted and their responses observed about one month later (in the case of paddy rice, additional data on total yield were taken after the plants had matured). were controlled during and between plantings by hand, and in the 2J �Philippines experiments also by application of a different herbicide: paraquat. Fertilizer was applied according to locally-established needs; during plantings, light surface cultivation was applied to the soil. The main characteristics recorded were number of surviving plants; % height and wet weight either of all plants on a plot or of a number of plants selected at randan; number of leaves and, for paddy rice, of tillers (side shoots emerging near ,the ground); plant color; and symptoms of herbicidal injury. Estimates of general vigor (on a scale of 0 to 10) and of ground coverage (i.e., the portion of a plot covered by the foliage of the crop, in percent) were also made for some plantings. In general, the most useful measurements--since they provided the clearest indication of herbicide effects or their disappearance—were survival., plant weight, and degree of herbicidal damage). In the case of paddy rice, the plants were grown to maturity and the yields of air-dried grain determined. The results are expressed as the time, in weeks, from the_ date of the herbicide application tp_ the date of that planting in which no effects on the growth of the plants, as determined by survival and weight, were noted, and if these times are different, also the time from herbicide application tp_ the date of that planting in_ which any herbicide symptoms had disappeared. This procedure is illustrated by Table V., which contains data for two. species that are relatively susceptible or resistant to the herbicidal agents, and by Figure 1, which is derived from these data. Two experiments were carried out, one in the Philippines and one in SVN. The Philippines experiment was conducted on the experimental farm of Tropical Agri-Search, Makati, Rizal Province, Philippines at 22 �Table V. Survival, growth and herbicide symptoms of naice and peanut* grown in soil trcatad with 3—1—1/3 gal/aera of Agents Orange and White at different tioee after application. (Experiment at Alabang, Third Series.) Survival and growth (fresh weight after 4 weeks) are expressed as percent of controls (plants grown on non-treated plots), symptoms on a scale from ++++ (very heavy) to 0 (absent), Interval between spraying the soil and planting Agent Orange Agent White Herbicide Symptom* Surviving Plants Plant Weight 1/3 1 3 (Gallons per acre) 1/3 1 3 (Gallons per acre) Surviving Plants 1/3 1 3 1/3 1 3 (Gallons per acre) (Gallons ptr acre) Plant Weight Herbicide SyeptoM 1/3 1 3 (Gallons per acre) (Gallons per acre) 1/3 1 3 ro Mais* 4 weeks 96 84 89 96 126 138 0 0 0 109 129 64 60 83 15 weeks 102 112 115 123 148 143 0 0 0 67 01 89 69 « 83 30* 36* 51* 0 0 0 96 0 0 0 + + + + • » Peanut 4 weeks 102 100 15 weeks 148 102 40* 128 89 101 99 + ++ *+* 124 115 128 0 0 0 22 weeks • Difference froa control statistically significant. 0* 58* 53* + + + 108 133 133 95 117 112 0 + + 78 112 77 99 87 104 0 0 0 �CROP AGENT AND DOSE (gal/acre) OR 1/3 1 3 WH ill 1/3 1 3 N "^ OR ro z 11 1 n. WH 1/3 1 3 1/3 1 3 8 8 1Q 12 14 15 18 20 22 TIME AFTER HERBICIDE APPLICATION TO SOIL (weeks) FIG. 1. Persistence of herbicide effects in naize and peanut (graphic representation of the results in Table V). The solid bars show the time between herbicide application to the soil and that planting in which effects of the herbicides on survival and Growth (as fresh veight) were no longer present. The broken bars show that tine after which no herbicide synptoiT.s were evident. lack of a broken bar means that herbicide symptoms were not present at all, or that they disappeared at the sane time (i.e., in the same planting) as effects on survival and growth. Thus, the effects of Agent Orange (OR) on maize were no longer present in the planting made k weeks after herbicide application; those of Agent White (WH) at 1/3 and 1 gal/acre were not present in the same (It-week) planting and those at 3 gal/acre in that planting after 15 weeks. (Maize, as well as other cereals and grasses, exhibits few if any of the herbicide symptoms found in broadleaf plants, such as twisting of stems'and leaves, reduction of the leaf blade, curling of leaf margins.) Effects of Agent Orange on survival and/or growth of peanuts on soil treated with 1/3 and 1 gal/acre were no longer present in the U-week planting, but herbicide syuptoms remained present until the 15-week planting, while on soil treated with 3 gal/acre, effects on survival (and herbicide symptoms) were present until the 15-week planting, but both had disappeared In the 22-week planting. In peanuts grown on Agent White-treated soil, effects on survival and growth were no longer present in the 15-week planting; and herbicide (plcloram) symptoms on soil treated with 1 or 3 gal/acre disappeared In toe 22-week planting. �Alabang, near Manila, under a subcontract with the International Rice ""search Institute, Los Banos, the Philippines. The experiment i3 "* jf -onslsted of two parts; one for paddy rice and one for "dry crops" t'.-.aize, sorghum, sweet potato, mung bean, peanut). The rice was planted in 82 by 66 ft (25 by 20 m) paddies, three : nldies were used for*each of the two agents (Orange and White), and each 1 i B*c *» w a* !^**8W - : o.ioy was subdivided by bunds into four sections for the three dose :ovols (3, 1, and 1/3 gal/acre) and an untreated control. Thus, each I *> 0 Jj JC i -rt £ P.** ''TI S.fc5 l |fa'* I gd-3 § 8 i! ^ *g 3 5% Tcntnent was replicated three times. Flooding was arranged in such a ..av that water could not move from one plot to another. The dry crops at Alabang were arranged in three different series. :.:i one series, the herbicide application was made on February 2, 1972, l-iring the dry season, and the first planting occurred on February 25, i'72. Plantings were repeated at six-week intervals; all plantings were Irrigated by soaker hoses and hand watering as long as the dry season t> *T8 Vested. In the second series, the herbicide was applied at the same • :.no as in the first (February 2, 1972), but the plot was allowed to !3 «d r---nain fallow until the onset of the wet season. Finally, in the • ::ird series, herbicide application was delayed until the wet season ii:: i was carried out on May 3, 1972. The first plantings in the second 'i:.l third series were then made on May 30, 1972, simultaneously with the •;ilrl planting of the first series (which had to be delayed one week o o TI a -J •••••ause of heavy rains). The objective of this threefold setup was to »': *ain some information on the persistence of the herbicides in the alst;nce of rain. One planting (July 16-17, 1972) was partly lost in a h'.-avy typhoon on July 19-20 and was therefore repeated on August 12-lU, 25 �resulting in a disruption of the schedule. The heavy rains caused losses of topsoil and may have thus caused some loss of herbicide as veil. However, a careful inspection of the pattern of herbicide symptoms in the most sensitive crop of this experiment—peanuts—gave no indication of cross contamination of the different agents and dosages. The number of replicates in each of the three series was three for the controls (no herbicide) and two for each of the three herbicide levels. Reduction to two replicates was necessary because of the restricted area available. The experiment in SVN was conducted at the Ea-Kmat Agricultural Research Station at Ban-Me-Thuot, Earlac Province, with the authorization of the GVN and the Director of the Agricultural Research Institute of the Ministry of Agriculture of the RVN, Dr. Thai-Cong-Tung. It was most capably supervised by the Manager of the Station, Ing. Nguyen-Van-Thoi, and his staff, in particular Ing. Truong-Duc-Bao. This experiment was restricted to crops capable of growth when receiving only natural rainfalJ The individual herbicidal treatments and the controls consisted of three replicates. The crops were dry (upland) rice, maize, sorghum, sweet potato, nrung bean, and peanut. Because of poor germination and growth of sorghum during the first two plantings, and because herbicide effects had mostly disappeared by that time, sorghum was replaced by soybean afte. these plantings. Rice, mung bean, and soybean suffered heavily from insect attack and the data obtained were less complete than for the other crops; nevertheless, comparisons between plants on herbicide treated and untreated plots were possible in most cases. The herbicide applications were made on March 2U, 1972, at the normal starting time of the rainy season. The first planting was on April 22, and subsequent 26 �plantings were made at Intervals of six to seven weeks, with the last one (for Agent White-treated plots only) on October 25, 1972. As the rainy season In 1972 began unusually late and was relatively short, and as no Irrigation system was available, the finst and last plantings • * suffered from drought. The growth of the firs- two plantings was impaired by a heavy growth of weeds. The soil at Ban-Me-Thuot is representative of the "red soils" of SVN. The Committee would have liked to conduct similar work for alluvial soils, since they represent the soils of the main agricultural region of the country, the Mekong Delta. However, with the time and manpower available this proved beyond our capacities. It would also have been desirable to repeat all experiments for a second year, in order to gain some insight about annual variations, but this was not possible either, because of the time limitation under which we were working. It should be realized, however, that little critical research involving quantitative studies of the persistence of herbicides in the tropics has been done. Thus, the information pertinent to the situation in SVN collected by the Committee represents, despite its limitations, a significant contribution of new knowledge to this general problem. The results of the Philippines experiment are illustrated in Figure 2, those of the Ban-Me-Thuot experiment in Figure 3. For the Philippines experiment, only the data for the third series (herbicide Application and first planting at the start of the rainy season) are shown. In the first series (herbicide application and first plantings In the dry season, with artificial irrigation) the time course of herbicide disappearance was quite similar to the pattern of the third, 27 �n ii n CD <C UJ I $ r>_n - C—« i !?—n Q.-M .££ 3DNVUO C-o JJ—n C.-o £2-n C.-PJ C — PI J Si—pi £2~-r I I 1 31IHM FIG. Z. The COUTM of disappearance of the effect* el herbicide* on selected crop* grown on •oil treated with 3( 1, and 1/3 gal/acre of Agenta Orange or White. Experiment at Alabang, Fhlllpplnea. Bar* • time In weeks from herbicide application to 'the aoll to that aequentlal aowlng or planting where effect* of herbicide* on eurvlvul and gro.'th or yield (eolid bare) and herbicide uynptoma (broken bars) vure no longer obiervabl*. (Lack of a broken bar • herbicide symptoms either not evident, or disappearing «t aanc time aa herbicide effect* on •urvlval, etc.) For further explanation, see text, Table V, and Figure 1. Faddy rice (variety HI-ZO, one of the "miracle varieties" produced by the International Rice Research Institute) wa* planted aa 3-week old nursery seedlings; sweet potato (local variety) a* cutting*: maize (meet corn, varletlei IV 601 and UFCA Synthetic #1 and #2), oorghum (variety Coaor jfe), nung bean (variety CES flk) and peanut (unknown varletle*) •• aeed*. Where vurietie* are known, the material was supplied by IRRI. Criteria for yield, survival aiid groulh: rice - grain yield; meet potato - *urvlval and length of longeat (hoot) other crop* -•survival and plant uclgkt (fresh) about k wetiki; after planting. �(JO*. I Itf . I/J 1/3 I 1/3 Sorghum The firat planting of sweet potato failed because of lack of rain, so no information is available until later sequential plantings. The second sowing of aung beans on the Orange plot, including the control (nontreated soil), was lost because of very poor germination. The effects of this herbicide at the 1 and 3 gal/acre levels may therefore have disappeared one sowing earlier than shown, i.e., 10 weeks after soil treatnent. c Sorghum was sown only twice, k and 10 weeks after herbicide application. In the White 3 gal/acre plots, socte effects on growth Bay still have been present in the second sowir.i;. It is probable that they would have disappeared by the next planting late, 17.S weeks after treatment. Soybeans were included or.ly beginning with the third sowing, 17.5 weeks after soil treatment. At this tine, Orange at all three levels and White at 1/3 gal/acre no longer produced any observable effects or symptoms on the plants. 'Peanuts still showed some plcloram symptoms in the fifth sowing; see text. 1 3 SMI POIMD 1/3 1 3 (a) 1/3 Mung torn Pcmt 1/3 1 3 1/3 1 3 Sorghum Potato 1/3 1 3 to) 1/3 1 3 '.1^3 <•> 1/3 Soybean Punut 1 3 1/3 1 3 10 12 14 16 IB 20 22 24 26 28 30 32 34 TIME AFTER HERBICIDE APPLICATION TO SOIL (weeks) FIO. 3. The course of disappearance of herbicide effects on selected crops grown on soil treated with 3, 1, and 1/3 gal/acre of Agents Orange or White. Experiment at Ban-Me-Thuot, SVN. Bars • time in weeks from herbicide application to the soil to that sequential sowing or planting where effects of herbicides on survival and growth or yield (solid bars) and herbicide symptoms (broken bars) were no longer observable. (Lack of a broken bar • herbicide symptoms either not evident, or disappearing at sane time as herbicide effects on survival, etc.) For further explanation, see text, Table V, and Figure 1. Sweet potato was planted as cuttings, the other crops as seeds. All crops were local varieties of unknown origin. Main criteria used to assess herbicide effects: sweet potato - number of surviving plants and length of longest shooti other crops - number of survivors and weight of plants (fresh), in all cases U-5 weeks after planting. �which means, of course, that the herbicide effects disappeared at correspondingly earlier calendar dates. In the second series (herbicide application in the dry season, but planting delayed for four months until the start of the wet season) the effects of the herbicides disappeared in general at the same time as in the third plantings. However, as long as symptoms were discernible they were somewhat more pronounced in the second than in the third series^ indicating a somewhat greater herbicide persistence. The reason for this is not clear; one possibility is that because of lack of competition by water the herbicide molecules were more effectively adsorbed to the soil particles and therefore somewhat less accessible to later loss and degradation. From Figures 2 and 3> the following conclusions can be drawn: 1. The herbicidal effects persisted in different crops for different lengths of time; i.e., the crops differed in their herbicide sensitivity. The three cereals (rice, maize, sorghum) were less sensitive than the broadleaf crops (mung bean, soybean, peanut, sweet potato) because the recorded deleterious effects stopped sooner. 2. The effects of Agent White lasted longer than those of Agent Orange. The main difference between the two agents is that White contains picloram while Orange contains 2,U,5-T; the observed effects can be attributed to the greater persistence of picloram. 3. In the Ban-Me-Thuot experiment, the persistence of the two agents, and particularly of .Agent White, was greater than in the Riilippines experiment. Symptoms of picloram injury were still evident in peanuts in our last planting at Ban-Me-Thuot, made about 31 weeks after herbicide application to the soil. AB this planting was completed at 30 �the onset of the dry season, and as the Riilippines experiment, second series (herbicide application to soil during the dry season, plantings Jelayed until the wet season) showed -hat the herbicides persist throughout a dry season, it is possible that some picloram symptoms might have been found if peanuts*had been planted again after the end of the dry season. The reasons for the difference in herbicide persistence between the two experiments may be due to any one or more of the following factors: (a) use of different varieties; (b) different soils; (c) lower temperature and less precipitation at Ban-Me-Thuot as compared to Alabang: rainfall during the period of the experiments at Ban-Me-Thuot was about 6k in., at Alabang about 90 in. including one typhoon with 7.25 in. in one day, and another'with 23.5 in. in two days, The results of our experiments, in their entirety, are in full agreement with past experience on the characteristics of 2,U-D, 2,U,5-T, and picloram. Specific and varietal differences in herbicide sensitivity are very well known. Indeed, the difference in the response of grasses and of many broadleaf plants to these compounds are the basis of most of their agricultural uses. Greater persistence of picloram, as compared to 2,U-D and 2,U,5-T, is also well established, and so is the influence of soil and climatic conditions on the disappearance of herbicides. More important than these variations is the fact, clearly brought out in both experiments, that even though the soil received the massive dose of 3 gal/acre, the herbicides did not affect growth, even of highly sensitive crops like the legumes, for more than about 30 weeks. Even if peanut plantings at Ban-Me-Thuot should show some picloram symptoms one year after soil treatment, it should .not be overlooked that effects on 31. �Growth and survival had disappeared after 17.5 weeks. It should also be appreciated that our results are overestimates in two respects. First, although the highest dose of herbicides used in our experiments, 3 gal/acre, was that used on the military herbicide missions, it is considerably in excess of what would in most cases reach the soil at .» least on a first mission over a particular region, when a major part of the herbicide would be intercepted by the vegetation and never reach * the soil in an active form. Second, if herbicide effects were present in a planting that was made four weeks after the soil treatment and observed for another four weeks, but were absent in the next planting, made 15 weeks after the soil treatment (e.g., the effects of Agent White on survival and growth of peanuts in the Philippines experiment), this result is shown as "no effects after 15 weeks." However, the herbicide may in fact have dropped below the effective level for this crop any time from 8 to 15 weeks after application to the soil. Forest Sites Experiments with forest soils were conducted on a cleared forest site on Mount Makiling near Los Banos, the Philippines, kindly provided by the Philippine Department of Forestry, and on a site presently used as a plantation, about 2? years old, of Hopea odorata, a dipterocarp, at the Ea-Knat Station at Ban-Me-Thuot. The former site consisted of two plots, 100 by 50 ft (30 by 15 m) in size, the latter of two narrower strips about 90 and 96 ft ( ? and 29 m) long and 6 ft (1.8 m) wide. The 2 plots were separated by buffer zones to exclude cross contamination of the two agents. One plot was sprayed with Agent Orange and the other wit; 32 �Agent White; the dos*.1 was 3 gal/acre, i.e., the rate used, by military spray missions; and the ground was cleared of vegetation as in the experiments with agricultural soils. At Los Baiios, both 10-in. (25 cm) .mrface samples and 30-in. (75 cm) cores were taken. At Ban-Me-Thuot, hocause of the dry conditions, the soil was very hard and only surface comples could be taken except on the last sampling occasion. Residues were determined by chemical methods alone; the results were, however, in agreement with observations on natural revegetation of the sprayed plots. The results of the Los Banos experiment are shown in Figure b, those of the Ban-Me-Thuot experiments in Figure 5- It can be seen that both 2,**,5-T and picloram disappeared from the soil quite rapidly, but picloram faded more slowly (it must be remembered that the initial dose of picloram was only 25 percent that of 2,U,5-T). The disappearance was greatest in the period immediately after herbicide application and then became relatively slower. It should be noted that the ordinate axes in Figure k and 5 (and likewise in Figures 6 and 7) are on a logarithmic scale; the: absolute drop iln the early period is thus much larger than may be apparent. For example, the picloram content in the top 10 in. of the Los Banos soil dropped from the theoretically-applied •lose of 1.6 Ib/acre to O.U9 Ib/acre, in 13 days to 0.29 Ib/acre, and in 31 more days to less than 0.02 Ib/acre. By the end of the experiment, ItJ} days after application, it had dropped relatively much more slowly, to 0.008 Ib/acre. The disappearance of 2,U,5-r was more rapid than that of picloram, considering the almost 10 times higher initial dose, but the difference was not striking, and by the end of the observations (189 days 33 �2.0 < 10 1.0 - < Los Banos Forest Soil 2.4,5-T 0 0-10 in. (0-25 cm) » 0-30 in. (0-75 cm) 1.0 Los Banos Forest Soil Picloram 0 0-10 in. (0-25 cm) x 0-30 in. (0-75 cm) 0.1 I I 0.1 0.01 0.01 0.001 30 60 90 120 Days 30 210 B 60 90 120 150 180 210 Days FIG. U. Disappearance of herbicides (A, 2,U,5-T; B, picloram) from a forest soil on Mount Makiling near Los Banos, the Philippines. The applied quantities were 13 Ib/acre 2,U,5-T and 1.6 Ib/acre picloran. Samples were 10 and 30 in. (25 and 75 cm, respectively) deep. Abscissa - days after herbicide application, ordinate - herbicide level in spil, as Ib/acre, on logarithnic scale. Vertical bars represent the 5 percent confidence limits. �2.0 10 - Ban Me Thuot Forest Soil Picloram (Surface samples) Ban Me Thuot Forest Soil 2.4.5-T (Surface samples) 1.0 U) VJ1 0.1 I I 0.1 0.01 0.01 0 30 60 90 120 150 Days i i 1,1 i 210 240 270 0.001 0 B 30 60 90 120 150 Days 180 210 240 270 FIG. 5. Disappearance of herbicides (A, 2,U,5-T; B, plcloram) from a forest soil near Ban-Me-Thuot, SVK. The applied quantities were 13 lb/acre,2,U,5-T and 1.6 Ib/acre picloram. Surface samples (5 in. = 12.5 cm) only. Abscissa - days after herbicide application, ordinate - herbicide level in soil, as Ib/acre, on logarithmic scale. Vertical bars represent the 5 percent confidence limits. �at Los Banos, 249 days- at Ban-Me-Thuot) the levels had dropped either to slightly above or to below the detection Limit. Disappearance of both herbicides in the surface and deep samples of the Los Banos experiment (0-10 in. and 0-30 in., respectively) proceeded in a similar manner (the discrepancy on the 105th day is most probably due to variations in the samples). As already mentioned, results of observations on revegetation of i the treated plots agree with the chemical data, indicating rapid disappearance of both 2,U,5-T and picloram (and of 2,4-D). At Mount Makiling, 3-5 months after the herbicide applications, both the Orangeand the White-treated plots had been fully revegetated, with a major component of broadleaf herbaceous plants including wild tomatoes. The latter—a species highly sensitive to all three herbicides used—had produced ripe fruits and must have started growth two months If not earlier after herbicide application. Two months later, i.e., 5-5 months after herbicide application, the plots were covered mainly with grasses that had largely replaced the broadleaf species, and numerous (unidentified) tree seedlings were present in the grass. The only possible herbicide effect still noted was an off-color individual of Philodendron sp. in the White plot. Otherwise, the treated plots were indistinguishable from the surrounding vegetation on nontreated soil. At Ban-Me-Thuot, the Orange-treated plot was at the last observation ( ^ days after 29 treatment) fully revegetated with the same species that occurred in the untreated surrounding areas; the White-treated plot was still sparsely vegetated, but was being actively recolordzed from the untreated areas. 36 �"-irvrovo The experiments with mangrove soils wore performed in a mangrove ftfa at Chi-Linh near the city of Vung-Tau. This area was within the p-rineter of the National Popular Forces Training Center; permission :'or the experiments was granted by the Commander of the C3nter and the City Council of Vung-Tau. The exact elevation of the experimental plots la not known, but they appear to be qu.ite frequently flooded at high tide. On all days we visited the area we observed either flooding or evidence of recent flooding. For the Initial experiment, an area 17'+ by 96 ft (about 50 by JO m) was cleared of all vegetation and divided into three parts, each '6 by 1*8 ft (about 30 by 15 m), separated by 15 ft (U.5 m) buffer strips. , Ono of the outer parts was sprayed with 3 gal/acre of Agent Orange, the oilier with the same amount of Agent White; the center part remained untreated as a control. Spraying was carried out at low tide, when the soil was dry. Soil surface samples were taken for the first time one -lay (two tides) after the spraying and sampling of both surface samples and cores was repeated five times: 20, 40, 72, 119, and 201 days after spraying. Seedlings of two major mangrove species, Rhizophora aplculata and Ceriopg tagal, were planted in groups of 100 at the time of the second, third, fourth, and fifth soil sampling and were observed about 2)» 35, and 50 weeks after the date of spraying. The number of groups was originally six per treatment, but in the Orange plot some groups were on the margin of the sprayed area and were discounted, reducing the c—b*r of some plantings to four. The results of this experiment, as "Mangrove Cleared," are shown in Figures 6 and 7. 37 �2.0 10 1.0 Vung Tau Mangrove Cleared Vung Tau Mangrove Cleared Picloram 0 Surface samples x Cores 2.4.5-T 1.0 0.1 © Surface samples * Cores I , - (i 0.1 - 0.01 I I - 1 1 © 0 O 0.01 I) , i i 30 i 1 60 j 1 1 1 1 120 90 Days 1 1 ISO 1 1 180 t 0.001 1 210 i 30 B 60 J- 90 120 Days i 150 i 180 210 FIG. 6.- Disappearance of 2,k,5-T (A) and picloram (B) from cleared mangrove soli. 2,U,5-T was applied at 13 Ib/acre, picloram at 1.6 Ib/acre. Surface samples were taken with 5-in. high metal cans, cores with a soil sampler 30 in. long, but the cores were usually shorter because of compacting and because of occasional loss of part of the core. Abscissa - days after herbicide application, ordinate - herbicide level in soil, as Ib/acre, on logarithmic scale. Vertical bars represent the 5 percent confidence limits. �w jJ! j; "»"7 1 t 1 to S <3 £ 3D .1 1 2 » ^^ ^ivrT ; |! 1 SK; Is 3 ;j : *f 1 ^•'j ^ ^ a i ' -rf^ "^ "7 $ *!•"-, _ I j. j. T'.u "j= 1^7 = •'it i ^ "• 5 t- "•P : i |<: « f 1 Y: 3I5:;- j!! 10 : !'! CONTROL • ; ' r? J ji: j rrl rfl rtf WHITE CONTROL F-nlir.jj V.iin Dam md THIMI Alln Sgr« '•••19 Ul vo 100 90 - .*L jiJ qr N IE I 1 i» o S i ,o < October 1971 -MWerki AflerS^rfving •I-*i ill :• i t; CONTROL ISNjMrnbnign -B .-.-edit Allffi Sfayng WHITE ' S • ;! i Hi< 1 9 : — " T ; " ;p i ; f JT S 1 ; • \ ORAM3E 1 MUCH 1973 -SOW— I n AfMi Soraying Tl" n A ORANGE n L-r-pP f-J ' WHITE « 73 ~ i] CONTROL ORANGE ».M il>h 4 & ^:p! £ € -1 L l i —1;5 1 I i t / i 1 (-i t j 1 CONTROL ••^ ~*''IC, : 'i i I n-n r-w-n , | F I !i:.5 I i [••] .';..J WHITE 1 I'^i L' TfIF 9 ORANGE \ ^9 . •::' j$ I fO.j ». -1 II I VUNG TAU MANGROVE CLEARED CEHIOPS w K'i II n r/i '• j ORWiat E 1 WHITE PUmmgi Wiih Odm •xl Taaii After Spiav'ng rrl ri i ^ B Am • CONTROL ORANGE 4 Ocnbw 1972 ""29 Wetki Alter Spraying WHITE CONTROL ORANGE WHITE 15 NMmbtr 1972 •*35 Wifef Afur Spr lying CONTROL ORANGE WHITE 1 Uvdt 1973 "^50 IVvcht Alltr Spriying FIG. 7. S-irvival of Rhizophora and Cerioiaa seedlings on cleared mangrove soil treated with Agent Orange (3 gal/acre) or Age-it White (3 gal/acre), or untreated (control). On the left, the situation at the start of the consecutive plantings ( 0 seedlings per group) is shown; going to the right, the survival at different 10 observation dates. At any one observation date, compare plantings of the same date, e.g., the April 6 control plantings with the plantings on Orange- and or. White-treated soil of the same date, and siailarly with the April 27, the May 33, and the July I1* plantings. �Figure 6 Illustrates the disappearance of 2,^,5-T and picloram from the soil. The trend is quite similar to that found in the forest soils (see Figures k and 5): an initial rapid rate of disappearance that falls off with time. The very marked drop one day after spraying, apparent especially in the case of picloram, may be in some part due to * washing out by the tide. Also, particularly in the case of picloram, the cores contain consistently higher levels of herbicide than the sur*i face samples, suggesting that the latter had penetrated into subsurface layers and possibly further. The levels of both herbicides 201 days after spraying were either near the lowest limit of detection, or below. Figure 7 summarizes the results of the planting experiments. Two features stand out. First, survival was low. Twenty-nine weeks after spraying, only between about 3 and 20 percent of the Rhizophora seedlings were still alive, the later plantings doing relatively better than the earlier ones. Most of the seedlings of the earliest Ceriops planting were dead, but this was mainly because they were transplants from a prepared bed; they had already formed roots and did not survive the shock of transplanting. In the later plantings, seedlings were collected from neighboring trees and survival was better. The decline in survivor numbers continued, although at a slower pace, to the last observation. One reason for seedling death is most probably Injury by crabs; seedlings with bitten roots were found partially pulled into the soil. However, we are in no position to say whether crab damage is a major or minor cause of the seedling loss observed. Second, even in the earliest planting (made three weeks after �, -«.-a and when the herbicide content of the soil was still 0.42 to *, . »j «-"O C '•»'• lb/acre of 2,U,5-T and O.OlU to 0 0 9 Ib/acre picloram) there was .2 •*•> ilff'.-rence in survival between the seedlings on the Orange, the White, »r.t the control plots. For example, on the October k observation date, • >•.«• survival in the April 6 planting of Rhizophora on the control plot „»« . 7 percent, on the Orange plot k.2 percent, and on the White plot ^ . ; percent; for the July Ik planting the values were 1 . , 18.5, and v 87 2l.'f percent, respectively. By the last observation date, the values Jr. the April 6 planting had dropped to 3-0, 3-0, and 1.6 percent, respectively, and in the July lU planting to 10.4, 6.0, and 10.7 percent, respectively. But in no case were there large differences between the rontrol, Orange, and White plots within plantings of one and the same 4ntr«; that is, there was no effect of herbicide residues on establishfr.t of Rhizophora and Ceriops seedlings. Because of this result, which was somewhat surprising in view of th* sensitivity of mangrove communities to aerial application of herbiclle, and because of the poor seedling survival, the experiment was rrfeated; however, it was modified to simulate conditions in an intact aar.grove that had not been cut or sprayed with herbicides. For this 2 purpose, 27 microplots of one square m (1.2 yd ) were cleared of vegetation. Eighteen were hand-sprayed, nine with Agent Orange and nine with A*?ent White at the same rates as in the "Mangrove Cleared" experiment; the last nine remained as untreated controls. Soil surface samples and cores were taken 26 or 28, 45, 82, and 138 days after spraying; Rhizophora •ri Ceriops seedlings were planted 4, 6.5, and about 12 weeks after *;r*yir.g, on each occasion 40 seedlings per plot, three plots each for �Orange, White, and control. Figure 8 shows that disappearance of the herbicides (2,U,5-T and picloram) proceeded much as in the "Mangrove Cleared" experiment. Perhaps it occurred a little more rapidly, since 2,U,5-T had dropped below the detection limit by 138 days in both surface samples and cores (in the former, it was undetectable even at 82 days) while in the "Mangrove Cleared" experiment traces were still detectable in core samples after 201 days. It should be noted that the soil of the microplots site contained more sand than that of the "Mangrove Cleared" experiment; tidal flooding may also have been somewhat less frequent. Figure 9 illustrates the behavior of seedlings. Survival was much better than in the "Mangrove Cleared" experiment--and in Rhizophora better than in Ceriops. Compare particularly the November 15, 1972 ' observation date in Figure 7 and the March 1, 1973 date in Figure $; both represent a similar period after spraying (about 3k and 35 weeks, respectively). It appears that the situation in a largely undisturbed mangrove can be a good deal more favorable for the establishment of mangrove seedlings than in a relatively large, cleared area in the mangrove. With respect to the herbicide effects, however, the microplot experiment gave results quite similar to those of the "Mangrove Cleared" experiment. Although at the time of the first planting the soil still contained substantial amounts of the herbicides, and although some seedlings of this planting on the Agent White-treated plots exhibited characteristic picloram symptoms (pale leaf color, ro3J.ed-up leaf margins), the numbers of survivors In this as well as in subsequent plantings were comparable on control, Orange-treated, and White-treated plots. In other words, both k2 �70 10 Vung Tau Mangrove Microplob Piclorwn 0 Surface samples x Cores Vung Tau Mangrove Microplots 2.4.5-T © Surface samples x Cores 0.1 1.0 I I 0.01 0.1 aoi 0.001 30 60 120 Days 'eiSO 30 B 60 90 Days 120 150 FIG. 8. Disappearance of 2,4,5-T (A) and picloram (a) from mangrove soil in small cleared plots within undisturbed mangrove. 2,U,5-T was applied at 13 Ib/acre, picloram at 1.6 Ib/acre. Surface samples were taken with 5-in. high metal cans, cores with a soil sampler 30 in. long, but the cores were usually shorter because of compacting and because of occasional loss of part of the core. Abscissa - days after herbicide application, ordinate - herbicide level in soil, as Ib/acre, on logarithmic scale. Vertical bars represent the 5 percent confidence limits. �VUNG TAU MANGROVE MldtOPLOTS RHIZOmOHA 120 100 w •*. Lai -1 3ij I i -I I I *•:; * s ! t-S 43 i 20 CONTROL ORANGE WHITE CONTROL ORANGE CONTROL ORANGE WHITE WHITE ISNonrnlicr 1972 Pllnlinqt WilhOmitndTliMI AtUl Sprtying CONTROL ORANGE WHITE 1 Mtrch 1973 - 34 WMkt AIW Sprlying VUNG TALI MANGROVE MICROH.OTS cfmon 110 • 100 . I A "• VJ S n S m •}" a ? CONTROL ORANGE WHITE nm.nji WuhDnnndTinM Ar«rStK-lY«l CONTROL ORANGE WHITE 4O«ob«1972 ~t2WMki Aim Spravmt CONTROL ORANGE WHITE ISNonmlar 1972 ~19WHki AlnrSmiiiiiv CONTROL ORANGE WHITE I March 1973 -MV*r«ii AllcrS FIj. 9. Survival of Rhizophora and Cerlo-pa seedlings la small cleared plots within undisturbed mangrove treated with Agant Orange (3 gal/«re), Agent White (3 gal/acre), or untreated (control). See legend, Figure 7. �experiments show that three to four weeks after application to soil at the rates of 13 Ib/acre 2,U,5-T and 12 ILb/acre 2,^-D, or 1.6 Ib/acre picloram plus 9-3 Ib/acre 2,U-D, none of these herbicides Impaired the establishment of mangrove (Rhizophora aplculata and Ceriops tagal) seedlings. Nor was the seedling growth, as expressed by height, different • .» in both experiments on herbicide-treated and control plots (Table VI). i GENERAL CONSIDERATIONS OF THE DISAPPEARANCE OF HERBICIDES APPLIED TO THE SOIL IN VIETNAM AND SIMILAR ENVIRONMENTS Comparative Patterns of Persistence in Different Soils , The disappearance pattern of phytotoxic residues from all the soils examined in the present study is similar to that found in the more extensive investigations undertaken in temperate regions. In whole core samples (Figures ^, 6, and 8), the percentage of the theoretical amount initially applied that was left in the soil by the final sampling occasion (up to 2^0 days after application) ranged from 0.15 to 0.23 for 2,U,5-T and from 0.12 to 0.5 for picloram. Examination of the residual phytotoxicity to selected crops (Figures 2 and 3) indicates that, for the highest rate of application, the interval required before symptoms of injury were no longer observed varied. For Agent Orange the time ranged from U weeks for a resistant crop such as maize to 18 weeks for a susceptible species such as peanuts. The data for Agent White were ^ weeks for maize and 31 weeks for mung bean. For peanut, at the highest doses slight symptoms of phytotoxicity were still observable at the final assessment. Comparable data from other parts of the tropics are meager �Table VIC. Average height (in.) of shoot above ground level of mangrove seedlings planted on herbicide treated and on untreated (control) plots. (Date of observation March 1, 1973) Rhizophora Planting Date Control Orange Ceriops White Control Orange White "Mangrove Cleared" Experimenta j May 28, 1972 July 14 , 1972 16.2 14.8 15.5 14.8 16.4 16.6 11.3 10.9 10.2 H.o 10.5 11.5 10.1 9.2 9.1 9.1 Microplot Experiment August 5, 1972 October 10, 1972 14.4 16.5 13.4 15.8 a 14.1 15.9 9.4 '. 98 "Mangrove Cleared" Experiment: Herbicide application March 17, 1972. Number of plants per treatment measured between 7 and 58. Number of plants in two earlier plantings (April 6 and 27) too sma.11 for valid observations. Microplot Experiment: Herbicide application July 159 1972. Number of plants per treatment measured 32 to 4$. Only first and last plantings shown. 46 �and none exist for mangrove soils. The results of some relevant experiments have been collated in Table VII. .In the Puerto Rico field study on two susceptible species the time for disappearance of phytotoxic effects was 8 weeks for a mixture of 2,U-D and 2,^,5-T and 12 to 53 weeks for a mixture of 2,U-D,A 2,U,5-T, and picloram. These intervals are in the same range as those found in the present investigation. In the Puerto Rican forest soil experiment, the 0.7 percent picloram residue at the end I of one year is not out of line with the range of 0.3 to 0.5 percent in Figures ^B and 5B, considering both the much higher dose (9 compared to 1.6 Ib/acre) and the much longer interval before the terminal sampling occasion. For the other three sources quoted, comparisons with the data from Southeast Asia can only be tentative. If it is postulated that the shapes of the degradation curves against uime are relatively independent of the initial dos^s, then on the basis of the data for the two forest soils (Figures ^ and 5) interpolation would predict a 90 percent loss of both 2,U,5-T and picloram within 15 days, whereas the observed intervals in Texas were 1.5 months for 2,U,5-T and 2.3 months for picloran. Similarly, the intervals recorded for a 90 percent loss under temperate conditions in Table VII again exceed those predicted for forest soils in SVN and the Philippines. The processes by which a herbicide is lost from the soil and that hence determine its persistence can be divided into those that remove the chemical unchanged from the system, and those responsible for its decomposition within the system. The first group consists of volatilization, leaching, runoff, and uptake by plants. The second involves chemical breakdown by biological and nonbiolo;_Tical processes. The data �Table VII. Disappearance of 2,lt-D, 2,4,5-T and picloram from soil in warmer climates. Herbicide and dosage Observation Field Study in Puerto Riqo (Bovey et al. 1 6 ) 98 Time (in months) for no symptoms on: Soybean Cotton Picloram, 6 Ib/acre 6.5 3 2,4-D + 2,U,5-T, 12 + 12 Ib/acre 2 2 2,U-D + 2,4,5-T + picloram, 6 + 6 + 3 Ib/acre 6.5 3 Forest in Puerto Rico " (Dowler et al. 1969) Amount left in top hQ in. after one year (in percent) Picloram, 9 Ib/acre Picloram, 27 Ib/acre 0.7 5.5 Field Studies in Texas (Bovey et al. 1969, Bovey and Baur 1972) 2,4,5-T, 0.5 and 1 Ib/acre Picloram, 1 oz/acre Picloram, 1 Ib/acre Time for 90 percent or more degradation (months) Less than 1.5 0.7 2.3 For comparison, Temperate Climate Conditions (average figures) Time for about 90 ( 5 1 0 7-0) percent degradation (months) 2,U,5-T 3-6 ("Report on 2,U,5-T," 1971, Kearney 1 7 ) 90 Picloram, 1 oz to 1 Ib/acre (Hamaker et al. 1962, Herr et al. 1$>66, Scifres et al. 1971, Bovey et al. 1 6 ) 99 3-16 �reported in this chapter must be interpreted in the light of (1) what is known from previous investigations of the importance of these factors on the behavior of 2,U-D, 2,^,5-T, and picloram in soil, and (2) the characteristics of soil and climate in SVN that may affect herbicide persistence. tt Volatilization and Photodecopposition The n-butyl esters of 2,^-D and 2,U,5-T, the constituents of ™ t i Agent Orange, are moderately volatile (see Section II C, I&rt A of the Report on the Effects of Herbicides in South Vietnam) and might be expected to vaporize quickly on contact with soil or plant surfaces under tropical conditions. The ability of plants to hydrolyze esters of 2,^-D to the nonvolatile acid is well known, but some loss as a vapor from leaf surfaces before entry is a possibility. In soil, rapid hydrolysis occurs even at low moisture levels (Smith 1972); this could reduce or eliminate losses in a vapor form. Moreover, under very dry conditions adsorption of volatile herbicides by the soil surfaces is well known to reduce such losses. The salt forms of 2,^-D and picloram used in Agent White are not appreciably volatile, and significant losses by this route can be discounted. It is probable, therefore, that volatilization from soil was not of major importance. In laboratory experiments the acids can be decomposed by the action of light, but under field conditions it is generally unlikely that such losses would be appreciable; this expectation agrees with the observations already recorded at Alabang. Here the residual toxicity of Agent Orange applied in the dry season (February 2), with the soil surface left undisturbed until crop planting on May 30 was similar to the residual �toxicity in plots sprayed on May 3 and also planted on Kuy 30. Thus losses from soil due either to photodeccmposition or volatilir.ation are likely on theoretical grounds to have been small. Moreover, the lack of phytotoxic symptoms in susceptible crops planted in our control plots . * immediately adjacent to plots sprayed with Agents orange and White suggested that volatilization was of little consequence. Runoff Any material applied to the soil is liable to be carried from the site of action when rain causes surface runoff and water erosion; the degree depends on the intensity of the precipitation, the soil characteristics, the nature of the surface, and topoprapliical features. The amount of herbicide removed in the surface wash will also be dependent on the interval since application. In the present experiments the only evidence for runoff after heavy rain caim* from (l) the phytotoxic symptoms observed below the treated plots (which were situated on a slope in the forest soil experiment in the Philippines) and (2) from picloram symptoms on untreated plots of very susceptible crops observed after the heavy typhoon at Alabang (noted above),, It has also been mentioned that in the mangrove experiment on the cleared site the hcrbicidal contents of the surface samples taken two tides after application r.ay in part have been affected by tidal waters carrying away some of the surface particles. Leaching The proportion of a herbicide that is physically bound within the soil matrix is dependent on its physicochmical characteristics and 50 �the nature of the soil. A combination of these properties determines the amount that is transported downwards through the soil by water percolating from the surface. This leaching action is dependent on two interacting sets of conditions. The downward movement of the soil solution will occur only when on average the amount of incoming rain exceeds the amount of water lost by evaporation from the soil and transpiration from the vegetation. The amount of herbicide that moves downward is dependent on both the freedom with which the soil solution can pass through the soil pores, and the concentration of herbicide in solution (which will be in equilibrium with the amount retained on the surfaces of the soil particles). . Thus losses of herbicides will be greatest when rainfall markedly exceeds evapotranspiration, the soil is free draining, and the retentive power of the surfaces is low. Losses will be minimal ( ) in the dry season, (2) when the soil is relatively l impermeable, and (3) if the capacity for adsorption is high. For individual herbicides there is the further consideration that the greater the degree of binding on any one soil type the less the liability of leaching. Against this background it would be expected that the capacity for retention would be less for the forest soils at Los Banbs and Ban-Me-Thuot than for the heavy clay soil at Alabang ajid the estuarinc muds of the mangrove experiments. It would also be expected that leaching would be least at Ban-Me-Thuot, which had the lowest rainfall over the experimental period. Since no basic data are available for the conditions of mangrove soils, the effects of the fluctuations ir.the water table and intermittent flooding of the surface are not predictable, but it is likely—at least during the initial phase—that each time the water table recedes from the 51 �surface layer there will be some transfer of the herbicide to a lower depth. There is some suggestion of this in Figure 6A and B, since the cores tend to have a higher content than the surface samples. It is very difficult to disentemgle the losses caused by leaching from the losses related to the activitieis of microorganisms. But at least in some experiments it would seem i;hat the component of leaching was small. For example, it is apparent that orr the forest soil experiment at Ban-Me-Thuot (Figure 5A and B) the progressive disappearance of both compounds took place under conditions where, subsequent to the initial spraying, lack of rain led to steadily drier soil over the first three months; hence, there cannot have been appreciable leaching from the surface layers. Moreover, if leaching is a major component it would not be expected that in the Pran Buri Calibration Grid picloram would be still present after eight years, with the residues largely present in the top layers of the soil. These findings are in general agreement with the literature and the expected behavior of 2,1<-D and 2,U,5-T where they appear as the parent acids, which have a low solubility in water. The extent of the leaching of highly soluble piclorara is dependent on the soil type; it is seemingly most marked in sandy soils (Bovey et al. 1 6 ) Leaching is known to occur to considerable depths, and those who 99. have looked at depths greater than 3-^ ft have generally found traces, although higher concentrations occur near the surface. On the basis of picloram1s greater mobility compared with 2,4,5-T (Helling 1 7 ) it is 91, puzzling to note from Table VIII that in the first Uk days the proportion of the remaining residue of picloram found in the top layr is much larger than that of 2,U,5-T. 52 �Table VIII. Changes in the distribution of herbicides in forest soil, Los Baffos, the Philippines. (Figures are percent of total found at each depth) Days Depth (in./cm) * 13 44 105 2,4,5»T j •Sop (0-10/0-25) Middle (10-20/25-50) Bottom (20-30/50-75) Ib/acre (average) 68.7 17.9 13.4 44.9 31.1 24.0 1.37 0.16 l 59.8 35.7 4.5 0.09 Picloram Top (0-10/0-25) Middle (10-20/25-50) Bottom (20-20/50-75) Ib/acre (average) 98.3 1.1 0.6 90.9 5.5 3.6 0.27 0.03 53 22.6 43.B 33.5 0.03 63.1 23.4 13.5 0.01 �Degradation It is well established that 2,U-D and 2,4,5-T are degraded by soil microorganisms~2,4-D very rapidly, 2,4,5-T more slowly. There is also firm evidence that repeated treatment with these herbicides accel• ,* crates the rate of breakdown. Factors that favor the growth of microorganisms, such as high temperatures, moist conditions, and a ready > availability of substrates, also enhance the level of decomposition. Such studies, including the chemical pathways of degradation, have been extensively reviewed by Loos in Kearney and Kaufman ( 9 9 • 1&) The course of degradation of 2,U-D and 2,4,5-T by soil microorganisms is well documented. At first little breakdown takes place (lag phase), then the rate builds up rapidly to a high level, which is followed by a third phase when the rate declines. The data of Figures IfA, 5A, and 6A share these common characteristics:: the amount of herbicide present in the soil at first falls rapidly, but later the rate of disappearance slows down. Thus, on the basis of the similarities between these field studies and the laboratory studies of metabolic degradation, it can be postulated that both in the mangrove and forest soils microorganisms played a major role. Since, however, there was no prior information on the capacity of the microorganisms present in these types of tropical soils to decompose the more resistant 2,4,5-T, an experiment was carried out at the Weed Research Organization (Hance, personal communication) 14 in which radioactive 2,U,5-T n-butyl ester ( C-la.beled carboxyl group) was applied to both mangrove and upland soils from SVN. The results confirmed that these soils were capable of degrading 2,4,5-T to carbon dioxide in the laboratory. When the output of radioactive CC2 was plotted against �time, the curves showed the typical lag phase associated with microbial degradation (Audus 196*0 • The soil samples used for this experiment were taken from the area of the dump site in the Di-An District, the KLnhNgang Canal in the Ca-Mau Peninsula, and from Site #1 in the Rung-Sat Special Zone. The last two were mangrove soils. Reference has already been made to the possibility that 2,U-D and 2,U,5-T may be decomposed by the action of light, but there are other nonbiologi<Jal processes that participate such as hydrolysis, oxidation, and reduction. The surfaces of soil components may or may not catalyze these reactions; this matter requires further study. The pathways of disappearance of pidoram are not adequately understood. The available evidence suggests that photo-decomposition, leaching, and microorganisms are all involved, with the latter probably playing a major role (Upchurch 1 7 ) Thus there is supporting evidence 93. that the losses of picloram with time shown in Figures ^B, 5B, and 6B are associated with the activities of microorganisms. To conclude, the data collected by the Committee from experiments and soil samples in SVN, the Rulippines, and Thailand all indicate that the general disappearance pattern of the three herbicides is in line with that well known for temperate regions. Moreover, all information the Committee was able to gather locally from farmers, village and district officials, and agricultural advisers indicated that crops could be grown again with no reductions in yield or other ill. effects the year following one or more herbicide missions. If crops were not grown it was either because of lack of security, or apprehension that the herbicide treatment might make the produce unfit for consumption. 55 �GENERAL CONCLUEIONS • Several deficiencies in our studies have been mentioned before. We were able to collect soil samples in only one forest area in SVN that had been sprayed during the war; we were unable to make collections in ,* forest areas that had received the relatively heaviest sprayings. We were also unable to repeat our own experiments for a second year, and to i conduct them on the other major soil type of SVIT, the alluvial soils. However, these deficiencies are counterbalanced by two important considerations. First, our evaluation of persistence included different agricultural and forest soils (in SVN and the Philippines) as well as mangrove soils. The sites were selected because local conditions happened to be favorable and, except for trying to take samples in heavily sprayed areas, and to include soils from vegetation types most extensively subjected to military herbicide sprays, no attempt was made to give preferential coverage to a particular soil type or any other factor. Second, our findings, at least those on the fate of herbicides in soils, are in excellent agreement with general experience on this problem. Thus viewed, our data possess considerable internal consistency and, in our opinion, permit a number o:f general conclusions, namely: 1. The behavior of herbicides in the soils of Vietnam and the Philippines is similar to that reported for soils elsewhere. 2. Only where herbicides (2,4»D, 2,^,5--T, picloram) were applied in very massive doses (the former two in the magnitude of 1000 Ib/acre, picloram at 20 Ib/acre: Fran Buri Calibration Grid; see Table U , are ) they still in part present in concentrations that are above the threshold �likely to induce phytotoxic symptoms in some species. 3. Where applied to mangroves at total doses approaching 100 lb/ acre of 2,U-D and of 2,U,5-T, or 3 or more Ib/acre of picloram, the herbicides may still be present at low levels. Although the amounts present varied between sampling sites, the levels were such that the likelihood of damage to crops that could be grown -under these conditions can be discounted. They were far below the levels, that, in our own experiments, had no effect on the establishment of seedlings of Rnizophora apiculata and Ceriops tagal. Moreover, seedlings and young plants of mangrove species that we observed in heavily sprayed areas of the BungSat, where 2,^,5-T and/or picloram were still detectable by chemical methods, did not exhibit any herbicide symptoms. k. In areas subject to one or two herbicide missions 1.5 years before sampling, no phytotoxic residues could in general be detected. 5. Our results indicate that after a single application of Agent Orange, even where conditions are such that all the spray reaches the soil, crops sensitive to 2,U-D or 2,4,,5-T may be safely sown after four to six months of wet weather; after an application of Agent White under the same conditions, resistant plants like rice and maize can also be safely planted four to six months after application. In this connection, it is appropriate to point out once more that the dosage used in our experiments, i.e., about 6 or 12 Ib/acre of 2,4-D and 2,^,5-T, and 1.5 Ib/acre picloram, applied to the bare soil, was considerably higher than the dosage that would have reached the soil when the forest or mangrove sites were sprayed for the first time because of interception of the spray droplets by the canopy. 57 �6. Claims that the herbicides as they were used during the war have rendered the soil "sterile," permanently or at least for prolonged periods, are without any foundation. It should be noted that these claims were contrary to all existing information for the herbicides in question. . * REFERENCES * * Audus, L.J., ed. 196U. The physiology and biochemistry of herbicides. Academic Press, London and New York. 555 pp. Bovey, R.W. and J.R. Baur. 1972. Persistence of 2,^,5-T in grasslands of Texas. Bull. Environ. Contarn. Toxlcol. 8:229-33. , F.R. Miller, and J. Diaz-Colon. 1968. Growth of crops in soils following herbicidal brush, control in the tropics. Agron. J. 60:678-9. , S.K. Lehman, H.L.Morton, and J.R. Baur. 1969. Control of live oak in South Texas. J. Range Manage. 22:315-8. Dowler, C.C., W. Porestier, and F.H. Tschirley. 1969. Effect and persistence of herbicides applied to soil in Puerto Rlcan forests. Weed Sci. 16:^5-50. Executive Office of the President, Office of Science and Technology. March 1971. Report on 2,U,5-T: a report of the panel on herbicides of the President's Science Advisory Committee. U.S. Government Printing Office, Washington, B.C. 68 pp. Hamaker, J.W., C.R. Youngson, and C.A.I. Goring. 1962. Prediction of the persistence and activity of tordon herbicide in. soils under field conditions. Down to Earth 23:30-36. Helling, C.S. 1971* Pesticide mobility in soils. II. Application of soil thin-layer chromatography. Proc. Soil Sci. Soc. Am. 35s737-^3. Herr, D.E., E.W. Stroube, and D.A. Ray.. 1966. The movement and persistence of picloram in soil. Weeds 1^:2^8-50. Kearney, P.C. 1 7 . Herbicides in the environment. Agricultural 90 Research Service, U.S.D.A., Beltsville, Md. WC/70/WP/26. _ and D.D. Kaufman, eds. 1969. Degradation of herbicides. Marcel Dekker, Inc., New York. �McKone, C.E. and J.R. Hance. 1972.. Determination of residues of 2,U,5-trichlorophenoxyacetic in soil by gas chromatography of n-butyl ester. J. Chromatog. 69:204-6. Selfres, C.J., R.H. Hahn, and M.G. Merkle. 1971. Dissipation of picloram from vegetation of semiarid rangelands. Weed Sci. 19:329-32. Smith, A.E. 1972. The hydrolysis of 2,4-dichlorophenoxyacetate esters to 2,U-dichlorophenoxyacetic acid in Saskatchewan soils. Weed Res. 12:364-72. Upchurch, R.P. 1973. Herbicides in plant growth regulators. In Organic chemicals in the soil environment, Vol. 2. C.A.I. Goring and J.W. Hamaker, eds. Marcel Dekker, Ire,, New York. 968 pp. 59 � Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Alvin L. Young Collection on Agent Orange Description An account of the resource <p style="margin-top: -1em; line-height: 1.2em;">The Alvin L. Young Collection on Agent Orange comprises 120 linear feet and spans the late 1800s to 2005; however, the bulk of the coverage is from the 1960s to the 1980s and there are many undated items. The collection was donated to Special Collections of the National Agricultural Library in 1985 by Dr. Alvin L. Young (1942- ). Dr. Young developed the collection as he conducted extensive research on the military defoliant Agent Orange. The collection is in good condition and includes letters, memoranda, books, reports, press releases, journal and newspaper clippings, field logs and notebooks, newsletters, maps, booklets and pamphlets, photographs, memorabilia, and audiotapes of an interview with Dr. Young.</p> <p>For more about this collection, <a href="/exhibits/speccoll/exhibits/show/alvin-l--young-collection-on-a">view the Agent Orange Exhibit.</a></p> Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Box The box containing the original item. 010 Folder The folder containing the original item. 0092 Series The series number of the original item. Series II Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Blackman, Geoffrey E. John D Fryer Anton Lang Michael Newton Description An account of the resource <strong>Corporate Author: </strong>National Academy of Sciences, National Research Council Date A point or period of time associated with an event in the lifecycle of the resource 1974-02-01 Title A name given to the resource The Effects of Herbicides in South Vietnam: Part B, Working Papers, February 1974: Persistence and Disappearance of Herbicides in Tropical Soils Subject The topic of the resource soil survey biodegradation ecological recovery Southeast Asia