Influence of Lime and Nitrogenous Fertilizers on the Population of Greenbugs Infesting Oats1

Abstract

In greenhouse tests on Toxoptera graminum, N from 2 sources applied 3 different ways at the rate of 0, 40, 80, and 120 lbs./acre was applied to Victor-grain oats grown in unlimed and limed Norfolk sandy soil. The plants were infested with a known number of greenbugs. As the rates of N were increased the population of greenbugs per unit of leaf surface decreased. The addition of lime also decreased the population of greenbugs, and the decrease was greatest where no N was used. The source and methods of applying the N had no significant effect on the populations.