Thielaviopsis root rot of soybean in Ontario and susceptibility of commercial cultivars to inoculation.
A survey of soyabean fields in SW Ont. in 1982 indicated that population densities of T. basicola in soil were 0-248.5 propagules/g dry soil. The incidence of infected plants was 0-100%, and the incidence of infection of individual root segments 0-80%. Although T. basicola was common in soyabean fields, the disease was not evident unless roots were examined carefully. A range in susceptibility was observed among 34 cultivars evaluated by root inoculation. Eagle was the most resistant.