Effects of plant culture method, plant age, zoospore concentration and temperature on zoospore encystment of Phytophthora and Pythium species on plant roots

Eight dicotyledonous and monocotyledonous plants were inoculated with zoospores of Pythium and Phytophthora species in order to assess the influence of plant culture method, plant age, zoospore concentration and temperature on zoospore encystment on roots. A significant effect of plant culture system on average zoospore encystment density was revealed and differences between plant species were observed. Zoospores encysted less on older seedlings of dicotyledonous plants, while no difference was observed for the monocotyledonous. Increasing zoospore concentration around the roots was related with increasing encystment density on roots and different patterns. Zoospore encystment density increased up to 25°C and then dropped or stabilized at 35°C.