Influence of Seeding Density and Row Spacings on the Resistance of Spring Wheats to the Wheat Stem Sawfly1

Abstract

In the spring-wheat varieties solid-stemmed Rescue and hollow-stemmed Thatcher infestation and cutting by the wheat stem sawfly (Cephus cinctus Nort.) decreased as the seeding density increased and row spacing decreased. The decrease in cutting was due in part to a lower infestation, which was in turn associated with a decrease in moisture in stems, diameter of stems, and plant height at peak of oviposition. Apparently sawflies selected the larger, more succulent stems in the lighter seedings for oviposition.