An official website of the United States government.

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Strategies for Improving the United States Responses to Fusarium, Downy Mildew and Chilling Injury to Production of Sweet Basil


<p>This project, a collaborative project between Rutgers, The State University of New Jersey, Cornell University, University of Massachusetts and the University of Florida working in collaboration with commercial basil growers, seed companies and buyers and distributors of fresh basil will </p>
<p>(i) identify and develop improved basil varieties with resistance/tolerance to downy mildew, Fusarium wilt and chilling-injury; </p>
<p>(ii) develop the standard laboratory techniques that can be used for the detection of mildew infested seed before distribution; </p>
<p>(iii) develop disease management strategies to effectively control downy mildew based on a disease forecasting and monitoring system and through the identification of effective organic and conventional fungicides; </p>
<p>(iv) develop cost: benefit considerations for each strategy, and </p>
<p>(v) conduct food safety workshops and developing educational materials. </p>
<p>This project will develop a robust screening program allowing us to quickly identify BDM and Fusarium-resistant basil breeding lines and commercial cultivars through plant assays which will meet the needs of the US and international marketplace. Procedures to be developed for seed testing will become available and set a standard in the basil seed production industry. Fungicide evaluations will greatly benefit both the conventional and organic basil production. Efficacy data on fungicides delivered through this project will be used to set industry priorities for seeking federal labels for fungicides through IR-4 and become industry standards for BDM control in conventional and organic basil production. The internet-based approach developed to track and report BDM movement throughout the US will be available to everyone. A robust outreach program will be developed for educating basil growers, diagnosticians, seed industry personnel and the general public regarding the availability of resistant basil cultivars and up-to- date disease management practices. Development of a genetic linkage map of basil for aroma composition, Fusarium and Peronospora resistance and chilling tolerance could be used in the future for marker-assisted breeding of new cultivars. Using marker-assisted selection rapid screening of basil seedlings from new crosses will allow the selection of those individuals having combinations of markers linked to the desired phenotypic traits for further field evaluations. Once a first generation linkage map is generated, a targeted effort to identify the specific genes conferring particular traits will become possible. This research seeks to improve chilling-tolerance and fusarium resistance in basil and identify genetic resistance to basil downy mildew.</p>

More information

<p>NON-TECHNICAL SUMMARY: <br/>Sweet basil (Ocimum basilicum L.) is commercially the most important annual culinary herb crop in the United States Yet; our domestic basil crop is currently threatened by a new devastating disease, basil downy mildew. This disease caused by Peronospora belbahrii has been impacting significant acreage commercially and even home gardens and nurseries. Basil varieties with downy mildew and Fusarium wilt (Fusarium oxysporum f. sp. basilica) resistance/tolerance are critically needed because the US production acreage is at-risk to these two economically-important diseases. The loss of methyl bromide for Fusarium wilt control and other fumigants in the near future removes the only reliable means of controlling Fusarium wilt, other than host plant resistance. No resistance and at present very few chemical controls are presently available for basil
downy mildew control. The development of improved varieties along with the development of a disease forecasting and monitoring system and improved food safety and disease management strategies is critically needed to allow US basil producers and distributors to remain competitive in the international basil marketplace and ensure only safe and registered chemical controls are used. This project will support the US and global basil industry in two critically needed areas: first, through the identification and development of basil downy mildew resistant and chilling-tolerant basil cultivars and species of which both cause significant crop and economic losses to US growers. Secondly, this project will develop disease management strategies that include bioassays for detecting infested seed, a disease monitoring and forecasting, as well as identify an array of organic and conventional
fungicides that can control downy mildew in commercial and organic farming operations throughout the US. This consortium brings together the leading researchers from Rutgers University, Cornell University, University of Massachusetts, and the University of Florida with stakeholder inputs from commercial growers in New Jersey and Florida, seed companies with buyers and national fresh produce and culinary herb distributors into a strong public: private sector partnership to solve their critical constraints in basil production.
<p>APPROACH:<br/> Downy mildew movement in the US. will be monitored (McGrath, Cornell) to determine whether the BDM pathogen moves northward as wind-dispersed spores through the eastern US, This movement can be similarly forecasted as a component of the ipmPIPE Cucurbit Downy Mildew Forecasting Program ( Reports of BDM occurrence logged at the web site will be examined along with wind trajectory information from the cucurbit downy mildew forecasts. Infected basil plants will be collected from farms and methods explored to find polymorphism in P. belbahrii. Ma (UMass) will lead studies on population diversity of this new pathogen. UMass will conduct a thorough examination of basil seed to determine its frequency of contamination and develop a baseline to determine if seed contamination is increasing or decreasing. Actively growing and virulent P.
belbahrii on infected basil plants will be shared with McGrath (Cornell) and Simon (Rutgers) for their screening to identify variation in disease-susceptibility among the different basils under controlled environment studies. Seed collected for the downy mildew survey will be cultured for F. oxysporum f.sp. basilica. Virulent isolates will then be shared with Rutgers for their basil breeding studies. Fungicide trials in FL, NJ and NY. Potential organic (OMRI approved) and conventional fungicides for BDM control will be evaluated in field trials conducted in FL, NJ and NY. A selected group of fungicides (i.e. different fungicide chemistries) will be evaluated each year in efficacy trials NJ, Florida and NY. Candidate fungicides will include those that have shown promise and those with proven effectiveness against downy mildews on other crops (i.e. mandipropamid, fluopicolide, propamocarb,
dimethomorph, mefenoxam, among others), along with the two classes of fungicides that are currently registered for use on basil, the phosphonics, and strobilurins (Raid, UF and Wynandt, Rutgers). Organic trials will compare a number of biofungicides currently available for use with standard fungicide programs. Core to this proposal is the development of varieties exhibiting disease resistance and chilling tolerance. We developed sweet basil lines exhibiting FR or CT and have confirmed BDM resistance in other Ocimum spp. Controlled crosses between these related species are planned to shed light on the inheritance of resistance to BDM. Lines identified that have two or all three of these important traits will be immediately used in the development of improved varieties. We will conduct a systematic screening of commercial cultivars for Fusarium wilt and BDM, as well as screening of the FR
and CT lines. Promising lines will be screened also by the industry. Our approach to development of improved varieties will combine classic breeding strategies with the development of molecular tools that can be used for marker-assisted selection. Food safety workshops and development of education materials for basil growers will be held annually. Cost-Benefit Analysis. Adoption of such disease control methods depend on the cost efficiency and effectiveness and a cost-benefit model will be developed for this study.
<p>PROGRESS: 2012/09 TO 2013/08<br/>Target Audience: We had four targeted audiences to whom our work is being addressed and whom are receiving information from the researchers involved in this program. The first are the commercial growers; the second are the home gardeners, the third are those from the commercial private sector serving to support the commercial growers (e.g. seed companies, those involved in developing chemical and organic controls for basil downy midlews, and buyers for fresh sweet basil); the fourth are other researchers and scientists including plant breeders and those plant pathologists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Monitoring program. In 2009 a program was started to obtain information on where basil downy mildew occurs and to try to determine whether the
pathogen could move northward through the eastern USA, now that it is considered established in FL, as occurs with the cucurbit downy mildew pathogen, and whether a monitoring program can assist growers to be prepared for downy mildew occurrence in their basil crop. Monitoring also will assist with determining whether seed is becoming a less important source, as expected. Each year a spreadsheet accessible by anyone has been set-up in Google Docs. The link is posted in an article about the disease, which is also up-dated annually. It is at In addition to date and location of the occurrence, growers and gardeners making reports have often included information about the occurrence and management experience, all adding to knowledge about this new disease. Those reporting are asked to include their e-mail address. As
part of the SCRI project, everyone reporting has been contacted to obtain more information and provide assistance with diagnosis to confirm the report. The monitoring program has resulted in samples being obtained for project PI R. L. Wick for his investigation of biodiversity in the pathogen. There were 64 reports posted in 2013. These documented occurrence of basil downy mildew in the USA in CA, CT, DC, FL, IL, LA, MA, MD, ME, NH, NJ, NY, OH, RI, SC, TN, VA, VT, WI, and WV. A report was also made from Australia. In each state (Florida, Massachusetts, New Jersey), field trials were conducted as training and demonstrations for commercial growers, seed companies and the public. Trainings in basil downy mildew identification and control were provided also in winter grower schools and summer field days, twilight meetings. How have the results been disseminated to communities of interest?
In each state (Florida, Massachusetts, New Jersey), field trials were conducted as training and demonstrations for commercial growers, seed companies and the public. Trainings in basil downy mildew identification and control were provided also in winter grower schools and summer field days, twilight meetings. Some examples follo Presentations at scientific meetings � ACMAP (American Council for Medicianlly Active Plants). 2013, Variation of essential oil constituents and antioxidant capacity in a segregating basil (Ocimum spp.) population. (Robert Pyne, H. Rodolfo Juliani, Adolfina R. Koroch, and James E. Simon, poster presentation). 4th nnual Conference. June 2-5, 2013. University of Massachusetts, Amherst, MA. � ASHS (American Society for Horticultural Science). 2013. Identification of Host Resistance to Basil Downy Mildew (Peronosporabelbahrii) Robert Pyne, Adolfina
Koroch, James E. Simon and Andrew Wyenandt. Annual Conference . July 22-25, 2013 Palm Desert, California � Flavor, Fragrance & Fragrance Conference. Breeding as a tool for generation of novel aromas in basil (Ocimum spp.) (Robert Pyne, H. Rodolfo Juliani, Adolfina Koroch, Thomas Villani and James Simon) 2nd Annual conference: September 12, 2013. � Zhang, S., Z. Mersha, R. N. Raid, Y. Fu, X. Liao, and J. S. Patel. 2013. Downy mildew of basil in US: What have we learned so far? The 10th International Congress of Plant Pathology, Beijing, China. August 29. � Zhang, S., Z. Mersha, R. N. Raid, Y. Fu, X. Liao, and J. S. Patel. 2013. An overview of basil downy mildew research in US. International Downy Mildew Group meeting, Beijing, China. August 27. � Zhang, S. 2013. Research on downy mildew of basil in US. Institute of Subtropical Agriculture, Chinese Academy
of Sciences, Changsha, China. September 6. � Zhang, S. 2013. An overview of research on downy mildew of basil at TREC. The 13th Biennial Meeting of the Florida Phytopathological Society, Davie, FL. May 8. � Mersha, Z., and S. Zhang. 2013. Tank mix and alternation of acibenzolar-S-methyl with reduced rates of mandipropamid for control of downy mildew on basil in the greenhouse. The Annual Meeting of APS, Austin, TX. August 10-14. (Poster) � Patel, J. S., S. Zhang, and Z. Mersha. 2013. Effect of plant age on downy mildew of basil. The Annual Meeting of APS, Austin, TX. August 10-14. (Poster) � Patel, J. S., M. I. Costa de Novaes, and S. Zhang. 2013. Management of downy mildew of basil by seed treatment with oxathiapiprolin. The Annual Meeting of APS, Austin, TX. August 10-14. (Poster) � Mersha, Z. and S. Zhang. 2013. Incubation and latent periods of
basil downy mildew (Peronospora belbahrii) as affected by temperature and wetness duration. The 2013 APS North Central Division Meeting, Manhattan, KS. June 12-14. (Poster) � Zhang, S. and J. S. Patel. 2013. Sustainable disease management of basil downy mildew by using biological and chemicals including a new chemistry. Basil Workshop, Homestead, FL. December 19, 2013. � Mersha, Z. and S. Zhang. 2013. Alternation and tank mix of acibenzolar-s-methyl with azoxystrobin or mandipropamid to control basil downy mildew. Basil Workshop, Homestead, FL. December 19, 2013. � Raid, R. N. and S. Zhang. 2013. Effectiveness of fungicide soil drenches for management of basil downy mildew. Basil Workshop, Homestead, FL. December 19, 2013. � Results from National Basil Downy Mildew Monitoring Program and Evaluating Fungicides and Resistant Varieties in New York. Basil
Workshop, Homestead, FL. 12/20/13. � Phosphorous Acid Fungicides: What Are The Best Uses? In the Vegetable Track Session on �Insect, Weed, and Disease Management Updates�. CCE Agriculture and Food Systems In-Service. Ithaca, NY. 11/21/13. � Organic Disease Management: Concepts & Facts Beginning Farmers Need to Know. Advanced Organic Vegetable Production Session for Beginning Farmer Service Organization Professional Development Training. Latham, NY. 10/30/13. Webinar Seminars, Teaching Practicums and Live Workshops � Homa, K., Simon, J.E., Wyenandt, A., Barney, W.P. (2014). Evaluating fungicides for the control of basil downy mildew; breeding for resistance to basil downy mildew.In: NJ Vegetable Growers Meeting,Atlantic City, NJ. � Homa, K., Pyne, R., Wyenandt, A., Simon, J.E., Koroch, A.R. (2013). Evaluation for fungicides for the control of
basil downy mildew; Genetics of basil breeding for resistance and tolerance to downy mildew, chilling injury and fusarium wilt. In: Basil Downy Mildew Workshop hosted by UFL. Homestead, FL. � Pyne, R. and Simon, J.E.. (2012). (2012) Breeding for resistance to basil downy mildew.In: NJTwilight Meeting. Rutgers Agricultural Research and Education Center,Bridgeton, NJ & The Snyder Research and Extension Farm , Pittstown, NJ. � Homa, K., Pyne, R., Wyenandt, A., Simon, J. (2013). Controlling Downy Mildew.13 May2013.Plant & Pest Advisory, Rutgers Cooperative Extension[online]. Available from: <; � Homa, K., Simon, J.E., Wyenandt, A., Barney, W.P. (2013). Evaluating fungicides in 2012 for the control of basil downy mildew.In: NJ Vegetable Growers Meeting, Atlantic City, NJ. � Homa, K., Barney, W.P., Wyenandt,
C.A. (2012). Evaluating fungicides for the control of basil downy mildew and evaluatingOcimumspecies, cultivars and breeding lines forsusceptibility to basil downy mildew.In: NJ Vegetable Growers Meeting,February 2012,Atlantic City, NJ. � Homa, K. (2012). 2012 Fungicide efficacy trials for control of basil downy mildew.In: NJTwilight Meeting. 2012. Rutgers Agricultural Research and Education Center,Bridgeton, NJ Disease Diagnosis and Management in the Home Vegetable Garden. Master Gardener Training Program, Great River, NY. 3/27/13 What do you plan to do during the next reporting period to accomplish the goals? Continued focus on plant genetics and breeding. Isolate and identify the genetic markers associated with resistance and susceptibiity of basil downy mildew in basils. Contined focus on developing new and more sweet basils resistant to basil downy mildew that also have
excellent aroma, flavor and taste (aromatic volatiles and more) and market characteristics (leaft shape, curvature, and texture). Examine whether the chilling tolerance and the fusarium resistance was inherited along with or retained in the new basil downy mildew resistant plants. From a pathological perspective, examine whether there is one or multiple races of the basil downy mildew pathogen. Continue to examine management techniques to mitigate or eliminate basil downy mildew with chemical control agents and other approaches. Survey the commercial growers for economic base-line losses of this and other diseases. Develop practical food safety guidelines around the use of chemicals associated with the control of basil downy mildew.
<p>PROGRESS: 2011/09/01 TO 2012/08/31<br/>OUTPUTS: This project seeks to develop a public and private sector consortium with University of Florida, University of Massachusetts with Rutgers to improve the sweet basil industry in the USA which has been seriously impacted by a new devastating disease, basil downy mildew and continues to be constrained by fusarium disease and chilling sensitivity. In this first year of this USDA SCRI funded project, activities included establishing field and greenhouse studies in three states, building a specialized screening facility at Rutgers to culture BDM, screen plants to controlled concentrations of BDM and retrofit new facilities for screening chilling tolerance. Parallel field and greenhouse studies were conducted to identify fungicides that could mitigate or control BDM. Staff and students were brought into the program and we
mentored graduate students; and gave extension presentations in all the partner states. Field trials established at the Rutgers Agricultural Research and Extension Center (RAREC) in Bridgeton, New Jersey looked at a wide range of chemical control agents while separately 42 basils, including 4 Rutgers breeding lines, 10 USDA accessions and 30 commercial cultivars, were made so as to exploit the diversity within the genus (Ocimum spp.). The field was inoculated by natural infection and symptoms later scored. Nine O. americanum accessions USDA accessions plus three USDA O. gratissimum) were resistant, showing no chlorosis or sporulation at any time. All O. citriodorum accessions and two USDA accessions, PI 253157 and PI 173746, experienced chlorosis and black necrotic spots, but limited sporulation. As all lines screened of O. basilicum show susceptibility, we used the most tolerant lemon
basil, cv. Sweet Dani, and crossed it with O. basilicum and generated F1 progeny. A mapping population is being developed through purposeful inter- and intraspecific crosses. An emphasis in our breeding program has been placed on hybridization of basil downy mildew tolerant (very low incidence of chlorosis and sporulation) species, Ocimum americanum cv. Spice and Ocimum citriodorum cv Sweet Dani, to the susceptible O. basilicum cv DiGenova (very low incidence of chlorosis and sporulation), and advanced Rutgers breeding lines (chilling tolerant and fusarium resistant). interspecific O. basilicum crosses have been made between Rutgers chilling tolerant and Fusarium resistant breeding lines and cv DiGenova. This may allow for a more stable genetic system in which to work within the genus as compared to interspecific populations. Currently, there are 14 F1 populations from 12 different
parents. Parents were cloned and are being maintained in the Rutgers research greenhouse. F2 and backcross pollinations have been made and populations will be generated in the first quarter of the second year. DNA is being isolated from parents and progeny (F1) of the potential mapping populations. Research continued to focus on developing chilling tolerant sweet basil. New selections and hybrids of chilling tolerant basils (4C for 72 hrs) were made. Sister lines of our Poppy Joes Sweet Basil, an OP tolerant to fusarium were evaluated and found to remain chilling tolerant. PARTICIPANTS: In this project, Drs. Simon and Wyenandt from Rutgers serve as the Project PIs. Simon leads the genetic and varietal work and Wynandt the pest control work. Genetics of the basil downy mildew (BDM) pathogen are led by Drs. Wick and Ma (UMass). Field and greenhouse studies are lead by Drs. Raid and Zhang
(UF), McGrath (Cornell) and Simon/Wyenandt (Rutgers). Economic analyses and crop budgets and associated costs of using pesticides is led by Dr. Govindasamy (Rutgers). Extension and outreach is lead by Drs. Bill Sciarappa, Wes Kline and Rick VanVranken for New Jersey growers; Mangan (UMass) for Massachusetts growers; McGrath (Cornell) for New York Growers, and Raid and Zhang for Florida growers. Dr. Koroch, BMCC, CUNY, and graduate student Robert Pyne are involved extensively in the genetic studies and breeding. Others are involved in nutrition and supportive work (Drs Juliani and Wu, Rutgers) and others in field work (Dr. Park and R. Pyne, Rutgers). This project is done with cooperation with seed companies (e.g. Johnny's; Stokes, Enza, others), produce buyers and others involved in the culinary herb industry. TARGET AUDIENCES: Target audiences include commercial growers and seed
companies(in USA), growers, processors and buyers and traders involved in the basil, fresh herb and processed herb industries. Relevance of this work also is aimed at home gardeners and horticulturalists given the diseases impact everyone growing and interested in basil. For our supportive service and collaborative role, our stakeholders also include other scientists, county, regional and state extension specialists. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Wyenandt, Christian A; Simon, James E
Rutgers University
Start date
End date
Project number
Accession number