<ol> <LI> To conduct and economically evaluate differences in pest control efficacy and strawberry crop yield of methyl bromide alternatives in ten large, commercial scale, field demonstration trials;<LI> To evaluate and validate, in grower field demonstration trials, the impacts of traffic pans, subsoiling tillage practices, and deep shank injection of alternative fumigants on strawberry crop growth, yield and sting nematode control of methyl bromide fumigant alternatives; <LI> To evaluate within all demonstration trials whether ground truthed and or optical sensor measurements reflecting plant size status at the end of the season is quantitatively descriptive of strawberry yield and the performance of methyl bromide alternatives; <LI> To conduct In-Service Training sessions for County Agents of the Florida Cooperative Extension Service, providing summary of current alternatives research and recommendations for transitional strategies.</ol> Within strawberry grower meetings: a) summarize the current regulatory situation driving reduced methyl bromide availability in a new regulatory environment for soil fumigants; b) define the urgency for evaluation and adoption of pest management alternatives to methyl bromide; c) as part of a continuing educational component, describe and demonstrate new fumigant application, flow metering / distribution systems, and plastic mulch products required for low rate fumigant applications; and 4) with the assistance of grower organizations (FFVA and FSGA) to: a) describe impacts of alternative treatments and within and between farm variability of pest control efficacy and strawberry growth; b) generate commodity based, acreage estimates of transitions to alternatives and c) to help formulate basic on-farm plans and recommendations to expedite transitional strategies of alternatives to strawberry growers which minimize pest, crop, and economic impacts.
Non-Technical Summary: Project goals include 1)To economically test next-best chemical alternatives to methyl bromide for nematode, weed, and soilborne disease control and comparative yield to that of methyl bromide in at 10 west central Florida strawberry fields; 2)In 4 of the 10 demonstration trials, to evaluate and validate the impacts of traffic pans, subsoiling tillage practices, and deep shank injection of alternative fumigants on strawberry crop growth, yield and sting nematode control of fumigant alternatives to methyl bromide; 3)In addition to hand harvesting, continue to explore and validate other quantitative and indirect measures of assessing and comparing relative differences in strawberry yield based on field scale (large strip plots) differences in average plant size, fruit stem counts, and fumigant treatment; 4) To first educate extension agents, then growers, farm workers, and other agriculturists about the current methyl bromide regulatory status, changes in fumigant labeling and use restriction following EPA reregistration of the soil fumigants, summarize alternatives to methyl bromide research, IPM, and to provide and formulate recommendations, timetables, and decision making tools to adopt methyl bromide alternative strategies within grower farming practices; 5)With the assistance of two commodity organizations to: a) describe impacts of alternative treatments, including within and between field variability to differences in pest control efficacy and strawberry growth; b) generate commodity based, acreage estimates of transitions to alternatives and c)to help formulate basic on-farm plans and recommendations to expedite transition to alternatives which minimize pest, crop, and other potential economic impacts. <P> Approach: For this project, the effectiveness of various fumigant alternatives, alone or in combination with various herbicide partners, will be evaluated to methyl bromide for nematode, disease, and weed control in large scale strip replicated plots within commercial fields. Application of all herbicides and fumigants will be made via grower equipment, in field sites with existing soilborne pest and disease problems and where double cropping is planned. The impacts of traffic pans and subsoiling tillage practices on strawberry crop growth, yield and sting nematode control with fumigant alternatives to that of methyl bromide will also be evaluated in large scale strip treatments within grower fields. Comparative differences in pest incidence, severity, and plant growth, vigor, and development will be periodically assessed during the growing season within replicate treated blocks. Although yields will not be measured at most demonstration site locations, meaningful differences in plant size distributions within and between treatments replicates will be recorded to infer relative differences in strawberry fruit yield.Statistical analyses and treatment comparisons will be determined statistically using SAS ANOVA (t-Test comparisons) (P<0.05). At the conclusion of the harvest season, a Greenseeker optical (chlorophyll) sensor will be mounted on a mobile ground based tractor platform to survey and map the size and color of strawberry plants in as many as 10 field demonstration sites.Groundtruth observations of the same fields will be collected for comparing with the Greenseeker NDVI data, including counts of large, medium, small or dead plants per 15.2m row section. Stepwise multiple regression analysis will be used to develop linear relationships between the NDVI and ground truth data. Semivariograms will be calculated with the georeferenced NDVI data in order to evaluate the spatial dependence of nematode infestations. Multiple linear correlation analysis will show the degree of variance in strawberry plant growth and survival which can be accounted for by the NDVI measurement.