Abstract
Several species of Pythium were isolated from damped off sugar beets and considered as the pathogens. Pythium betae n. sp. was identified as a new species. P. aphanidermatum (Edson) Fitz., P. spinosum Sawada, and Pythium spp. were also isolated. Sporangia of P. betae n. sp. are spherical, often oval. Germination is either by zoospores or by germ tube. Oogonia are rarely smooth, usually 2-3 spines, spherical, 14.3-21.3μ in diameter. Oospores filling the oogonium, rarely not filling. Antheridia one or two in an oogonium and attached at the lateral side.
