Assesment of the Damage of Defoliators on Peanut Grown as the First Crop in Cropping Systems

Abstract

Peanut is one of the crops that usually to be set into the rice based cropping pattern because it does not take roo long to maturity and needs small amount of water and also improves soil texture. However, there are many insect pests attacking peanut especially defoliators. Defoliators, especially leaf minor, are one of the most serious pests of peanut at Pimai site, Nakornrachsima province. To determine the damage caused by the defoliators, the experiments was designed in a randomized complete block with six replications and 6 treatments. Azodrin was sprayed depending on insect damage; ( I ) at 20-25% leaf damage (2) at 50-60% leaf damage ( 3 ) at 80% leaf damage (4) complete control and ( 5 ) recommended protection and untreated check was also included in this experiment. The result showed that yields of peanut were not significantly different among the treatments. It could be concluded that the control of peanut defoliators in the 1980 crop year at Pimai cropping Systems site was not necessary.