Survival of Botrytis cinerea in soil in South-Eastern Spain

The survival of Botrytis cinerea in sterile and unsterile soil at different temperatures and relative air humidities was investigated in south-eastern Spain. Conidia survived only 7 days at 40(circle) C but, depending on relative humidity, for 30-90 days at 22(circle) C. High air humidity (95%) was needed to maintain soil humidity (8%) at a level that favoured conidial survival. Conidia survived better in sterile soil than in unsterile soil, probably because of the presence in the latter of soil microorganisms antagonistic to B. cinerea . Survival of conidia in environmental conditions simulating those in a greenhouse was less than 28 days. Results showed that B. cinerea conidia cannot survive over summer in south-eastern Spain, and other primary sources of inocula are discussed.