Resistance in Soybeans to the Southern Green Stink Bug1

Abstract

The southern green stink bug [Nezara viridula (L.)] is a pest soybean [Glycine max (L.) Merr.] in many areas of the Southern U.S., particularly in Louisiana and other Gulf Coast states, as well as in other countries where soybeans are grown. To identify resistance to the southern green stink bug, 894 plant introductions and 26 cultivars of Maturity Groups V through VIII were evaluated in replicated single row field plots during 1975 to 1979 at Baton Rouge, LA. Damage ratings were made by classifying 100 seeds selected at random from each sample into four categories (none, light, medium, and severe) on the basis of visual damage.Stink bug damage was associated with plant maturity, with earlier maturing genotypes generally having less damage than later maturing genotypes. Significant differences in stink bug damage were detected among cultivars within Maturity Group VI. There were no differences in damage among cultlvars within Groups V, VII, or VIII. However, all cultivars had in excess of 60% damage and were highly susceptible to stink bug feeding.Highly significant differences in damage were obtained among plant introductions. Of the 894 strains evaluated, 67 had significantly less damage than the most resistant cultivar of similar maturity, and appeared to have resistance. These strains were from fairly diverse geographical locations and may represent different sources of resistance. There were no differences in damage among the more resistant strains within Maturity Groups V, VII, or VIII. However, the Group VI strain PI 171444 had significantly less damage than the other more resistant Group VI strains. This strain had the lowest stink bug damage rating in the test during all years, and appeared to have a high level of southern green stink bug resistance.