Resistance of the maize variety ‘JALAL’ against corn leaf aphid, rhopalosiphum maidis (Fitch), its impact on pest density and effects on yield and yield components

摘要

The corn leaf aphid Rhopalosiphum maidis, is a serious pest of maize whorl and inflicts heavy losses to the crop, particularly when the plant is under drought stress. Resistance in maize has been amply documented by various workers and is reflective of the numbers of aphid present. An effort is made to test the resistance of the newly released variety Jalal (Formerly known as PSEV-3 by the Cereal Crop Research Institute Pirsabak), along with two indigenous varieties, Azam and Sarhad white. Pesticides in three different formulation with full and half strengths indicated that imidacloprid as seed dressing with full marketable strength, resulted in lowest aphid density, higher yield and yield components in the Jalal variety, compared to granular and foliar formulations of Kadan and dimethoate, respectively. The granular application with full strength proved to be useful, as it stood second in its efficacy against Rhopalosiphum maidis, but the foliar sprays failed to provide effective protection against the pest. The mean yield of the three maize varieties showed that Jalal is the most productive. It resulted in 2928.76kg of grain per hectare compared to 2868 and 2814 kg per hectare in Azam and Sarhad white, respectively.