Greenbug Injury to Resistant and Susceptible Winter Wheat in the Field1

Abstract
A greenbug (Toxoptera graminum (Rondani)), resistant line (F7 Ponca×Dickinson Sel. 28A) of winter wheat was compared with a susceptible variety in the field, using two populations of greenbugs. Numbers of greenbugs were lower on resistant than on susceptible plants, and the resistant line produced significantly more grain than the susceptible variety. Plant height decreased, moisture content at harvest increased, and straw production decreased, more for the susceptible than the resistant wheat when infested. Test weight of grain appeared increased by greenbugs.