Submitted to: Joint Meeting of the American Phytopathological Society and Society of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2007
Publication Date: N/A
Technical Abstract: Nylon bags containing strawberry plant tissues infected by Colletotrichum acutatum or V8 juice-oat seed-vermiculite (V8JOV) substrate colonized by Phytophthora cactorum were buried at depths of 0, 10, 20, 30, and 40 cm in Yolo Fine Sandy Loam soil, which was non-solarized or solarized using a 6-mm plastic film. Bags were recovered after 51 (July 2 to Aug. 22, 2005) and 62 (July 23 to Sept. 23, 2006) days. Buried plant tissues and V8JOV substrate were plated on agar media to evaluate the survival of the pathogens. There was a significant difference in survival rates between solarized and non-solarized soils for both pathogens in both years. Neither pathogen survived at 0 to 40 cm depths in solarized soil. In contrast, both pathogens survived at all soil depths in the non-solarized soil, but there was a general decline in survival rate. During the burial period, accumulated hours above 35, 40, and 45°C at all depths were 445 to 853, 0 to 289, and 0 to 289 h, respectively, in 2005, and 301 to 334, 123 to 153, and 5 to 17 h, respectively, in 2006. Preliminary tests on thermal sensitivity of these two pathogens indicated that C. acutatum survived up to 14 days at 35°C and 2 days at 40°C, while P. cactorum survived ca. 2 days at 35°C and 4 h at 40°C. Solarization is a potential soil sanitation practice for strawberry nurseries, organic or conventional fruit production.