Development of propiconazole resistance in Sclerotium rolfsii sacc. causing fruit rot of ridge gourd

Survey of Sclerotium rolfsii Sacc. causing fruit rot disease of Ridge gourd (Luffa acutangula. L) was carried out in 14 localities of Maharashtra and Karnataka states. MIC of propiconazole on agar plates (in vitro) and fruit (in vivo) showed variation from 40 to 60 |jg/ml and 24 to 35 |jg/ml respectively. The effect of passage in the development of propiconazole resistance in the sensitive isolate indicated that continuously culturing the isolate for 8 successive passages increased the resistance. However, their culturing with Carbendazim, Mancozeb, Roko and Contaf alternately, resulted in decreased resistance. Similarly, the use of propiconazole in a mixture with other fungicides also decreased the resistance.