Macroconidiospores similar to those of Phytophthora sp. was produced on the cucumber leaves infected with Pseudoperonospora cubensis (Berk. et Curt.) Rost., when the leaves were kept in contact with water during the formation of the conidiophore. The macroconidiospore discharged 15 to 25 zoospores similar in size to those produced from the normal conidiospores.
