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Poster: Biology & Disease Mgmt: Mycology


Factors affecting germination of pseudosclerotia of Monilinia vaccinii-corymbosi on lowbush blueberry.
T. CASE (1), S. Annis (1) (1) University of Maine, U.S.A.

In the lowbush blueberry (Vaccinium angustifolium) industry of Maine, substantial yield loss can occur annually from the disease, mummy berry, caused by Monilinia vaccinii-corymbosi, if left unmanaged. The primary objective of this study is to better understand the environmental conditions that favor the germination of pseudosclerotia. We have conducted in vitro incubation experiments for the past two years, in which the germination of apothecia from pseudosclerotia has been observed in response to chill-hours (time between 0-7°C). To further identify conditions affecting the germination of pseudosclerotia, we have incubated pseudosclerotia over a wide range of chill-hours (800-2380 chill-hours), under three different soil saturations (50, 60 and 75%), as well as three different post-chill temperature regimes (10, 13 and 16°C). Germination of pseudosclerotia was greater under the highest temperature we tested (16°C), and moderate soil moisture conditions (60%). The development of apothecia from pseudosclerotia was affected by chill-hours, but varied substantially between treatments from different fields. Identifying the environmental conditions favoring the development of apothecia in the lab assists in managing this pathogen in the field through the development of a predictive model for germination. We will use this model in continuing our program for forecasting mummy berry, which gives growers an opportunity to effectively manage this disease.