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Poster: Biology & Disease Mgmt: Cultural Control


Using soil amendments to reduce survival of Botrytis cinerea sclerotia in Mid-Atlantic diversified farming systems
E. KOIVUNEN (1), E. Koivunen (1), C. Swett (1) (1) University of Maryland, U.S.A.

Botrytis cinerea causes major pre-harvest losses in a wide range of crops in the Mid-Atlantic, including strawberries, blueberries, raspberries, and grapes. Management challenges have escalated with the loss of soil fumigants as well as increased land-use intensity associated with crop diversification. In a summer 2015 field survey, Maryland fields had up to 350 B. cinerea colony forming units per gram of soil and 20% yield losses from gray mold. The objective of this project was to evaluate the efficacy of soil amendments in degrading B. cinerea sclerotia – the most resilient source of inoculum. In potted studies, sclerotia viability decreased in crab meal and leaf compost treatments by 91.7% (± 5%) and 96.7% respectively, compared to 71.7% (± 5%) in untreated soil sixty days after burial. Percent of sclerotia colonized by hyphal fungi was highest in the crab meal (86.7% ± 3.3%) and leaf compost treatments (93.8% ± 6.3%). Similar trends between sclerotia viability and colonization were seen in Maryland field trials: sixty days after burial, the leaf compost + crab meal treatment had the lowest sclerotia viability and the highest colonization by bacteria or yeasts. These studies suggest that soil amendments may hold promise in reducing B. cinerea survival and dispersal in diversified farming systems in the Mid-Atlantic, in part by promoting microbial colonization of sclerotia.