Differential reaction of cucurbits to Phytophthora capsici and P. melonis under green house conditions

Phytophthora root and crown rot caused by various species Phytophthora are the major threat to agricultural crops in Iran. Phytophthora melonis and P. capsici are reported on cucurbits in Iran but major species in cucurbits considered to be P.melonis and the importance of P.capsici in cucurbits has not been much investigated. In the present study the reactions of different cucurbits were compared to both species under greenhouse conditions. Two months old of 36 cucurbit species and cultivars were inoculated with vermiculite hempseed extract inoculums. The production of zoospore in drained water and reactions of cultivars were monitored during two months after inoculation. The results showed that cantaloupe and long melon were more susceptible to P. melonis and reacted differently to P.capsici. Pumpkin was resistant to both species but squash and water melon were more susceptible to P.capsici than P. melonis.