Seed Transmission of Spinach Downy Mildew. T. Inaba, Plant Pathologist, Division of Plant Pathology, National Institute of Agricultural Sciences, Yatabe, Tsukuba, Ibaraki 305, Japan. K. Takahashi, and T. Morinaka, Plant Pathologists, Division of Plant Pathology, National Institute of Agricultural Sciences, Yatabe, Tsukuba, Ibaraki 305, Japan. Plant Dis. 67:1139-1141. Accepted for publication 2 May 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-1139.

Oospores were collected by the seed-washing method in commercial seed lots from six of 11 spinach cultivars. These seeds were planted in sterilized soil in a growth chamber set at 15 C under natural light. The percentage of infected seedlings was positively correlated with the degree of oospore infestation of seed. We concluded that Peronospora effusa could be transmitted by the seed.