Environmental Effects on the Development of Brown Stem Rot in Soybean

Abstract

Brown stem rot of soybean (Glycine max), caused by Phialophora gregata, can cause significant yield reductions under favorable environmental conditions. Leaf symptoms may not always be present in the field; therefore, field evaluation must rely on stem symptoms. Eleven genotypes from maturity groups I, II, and III were planted in hill plots (three plants per hill) in two environments with different fertility and crop rotations for two years, 1988 and 1989, with and without inoculation with P. gregata. All genotypes showed greater development of brown stem rot stem symptoms under low fertility and in inoculated plots(.)