Infection and Development of Target Spot of Flue-Cured Tobacco Caused by Thanatephorus cucumeris

The effects of misting frequency and temperature regime on basidiospore infection and lesion development of target spot of tobacco were determined. Three isolates of Thanatephorus cucumeris (Rhizoctonia solani AG-2-2) produced hymenia and basidiospores equally when exposed to moderate temperatures and extended periods of high relative humidity. Optimum temperatures for hymenium production, infection, and lesion development were 16-30, 20-26, and 20-30 C, respectively. Hymenium production was very minimal at temperatures above 30 C or at any temperature in the absence of misting (...)