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Our goal is to validate the use of potential fumigant and biofumigant alternatives to methyl bromide to determine whether they are effective against soilborne pathogens, economically beneficial, and easily integrated into current production systems in the Midwest. Application technology including virtually impermeable film (VIF) will be investigated. We will accomplish this through: (1) Fumigants: Determine if currently registered alternatives and an unregistered product provide adequate disease control with positive economic impacts under large scale field use; (2) low density polyethylene (LDPE) and VIF plastic mulches: Compare the efficacy of fumigants applied under LDPE and VIF mulches for the control of Fusarium oxysporum f.sp. melonis of melons and Verticillium albo-atrum and Verticillium dahliae of eggplant; (3) Biofumigants: Measure and quantify the impact of biofumigants on nutrient cycling, and disease and nematode control in a large scale on-farm field evaluation; (4) Economic assessment: Determine if technically feasible alternatives to methyl bromide are economically viable, and provide an economic assessment that can be used to support Critical Use Exemptions; and (5) Extension efforts: Disseminate results through intensive contact with agents and farmer groups, field research and demonstration plots with grower cooperators, and through newsletters and meetings.
Non-Technical Summary: Methyl bromide is a critically important tool for managing soilborne diseases and nematodes in melon and eggplant crops in the Midwest. Although growers practice integrated pest management, soilborne pests are persistent in production fields and are especially difficult to control. Given the phase-out of methyl bromide in 2005, it is imperative that growers of these crops identify effective and cost efficient alternatives. Our goal is to test potential fumigant alternatives and cultural strategies for effectiveness and compare them with methyl bromide to determine whether they are: (1) effective against soilborne pests, (2) economically beneficial, and (3) easily integrated into current production systems in the Midwest. This project will investigate an integrated management program combining methyl bromide alternatives with biofumigants and the use of virtually impermeable film. Trials will be conducted with grower cooperators in Michigan and Indiana on a large scale basis. Research advances will be transferred through intensive contact with grower cooperators, farmer groups, and through demonstration plots, newsletters, meetings, and websites. <P> Approach: OBJECTIVE 1 (fumigants): Trials will be established in commercial Michigan and Indiana fields with a history of pest problems. Melon and eggplant plots will be adjusted to local field sizes and standard state practices. Six fumigant alternatives will be compared to a standard rate of methyl bromide in a randomized complete block design of 7 bed-blocks. The center bed will be untreated and two different treatments applied to the 3 outer beds on either side of the center bed. Nematodes will be evaluated by soil sampling and disease assessed by stand counts, vigor ratings, disease severity and incidence, date to harvest, fruit quality and yield. All data from all objectives will be statistically analyzed. OBJECTIVE 2 (LDPE and VIF plastic mulches): Efficacy of applying fumigants under LDPE and VIF plastic mulches to Michigan eggplant and melon crops will be compared in a randomized complete block design. Each block will be 7 rows with an untreated row in the center and the outer 3 rows on each side mulched with a different plastic. Fusarium colonies will be counted by soil sampling, weeds observed, and disease assessed by stand counts, vigor ratings, disease severity and incidence, date to harvest, fruit quality and yield. OBJECTIVE 3 (biofumigants): Seven Brassica cover crops will be tested as biofumigants against a control for Michigan melon and eggplant crops in a randomized complete block design with 8 plots per block. Soil sampling will establish nematode populations and nutrient recycling potential of the biofumigants (soil: E.C., pH, organic matter content, available plant nutrients; crop: foliar chlorophyll content), crops will be assessed for disease incidence, yield and quality. OBJECTIVE 4 (economic assessment): Each methyl bromide alternative will be economically analyzed and compared with methyl bromide by assessing potential revenue based on yield, quality, harvest timing against potential expenses associated with each alternative. OBJECTIVE 5 (extension efforts): Research results will be disseminated through intensive contact with grower cooperators, farmer groups, and via demonstration plots, newsletters, meetings, websites. Attendees at meetings and field days will be surveyed to determine whether they (a) have a clearer understanding of methyl bromide alternatives, and (b) have become more willing to implement registered alternatives.