Host Suitability and Susceptibility of Glycine max cv. Bedford to Race 1 of Heterodera glycines.

Populations of Heterodera glycines identifiable as race 1 reproduced on the race 1 resistant 'Bedford' soybean. A Beaufort County, North Carolina, population had an index of parasitism of 112% on Bedford in greenhouse tests. Indices of parasitism for this population on race 1 resistant cultivars Pickett 71, Centennial, and Forrest were less than 10%. The Beaufort County population had significantly greater reproduction on Bedford in microplots than did populations of race 3 or race 4. In field tests, a race 1 population suppressed yields of Bedford but not yields of Centennial. Based on these data, Bedford is no longer recommended in North Carolina as a race 1 resistant cultivar.