Efficacy of insecticides used for cotton insect pests management in Maswa district

Masters Thesis

The efficacy of insecticides used for cotton insect pests management were investigated in Maswa district from November 2018 to April 2019. The aim was improvement of cotton productivity through use of appropriate insecticides at recommended rates of application. The experiment was laid out as factorial in Randomized Completely Block Design (RCBD) with three replications in different locations, i.e. Shanwa primary, Maswa girls and Binza Secondary. The main plots consisted of three different insecticide concentrations, i.e. 0.8 of actual, 1.0 actual, and 1.2 of actual, mls while the subplots constituted the nine types of insecticides. These insecticides were applied three times according to the recommended application regime and the economic thresholds of each major cotton insect pest observed. Data collected were subjected to the ANOVA technique using SAS 9.3 statistical software and followed by Least Significant Difference (LSD0.05) means separation. Cotton insect pests dominant were Aphids followed by ants, which was one a beneficial. All the insecticides and rates of application tested decreased cotton insect pests densities and boll damage resulting in increased seed cotton yield when compared with control. Attakan, Confidor, Thunder and Duduba were highly effective against sucking insect pests of cotton. Based on Economic threshold (ET), dominant insect pests were; Aphids (20% of infested plants) and American bollworm (0.5 flared squares per plant) which was determined in order to initiate control measures which lead to increases in seed cotton production per area. ET rationalizes the use of insecticides to overcome inappropriate choices of insecticides, wrong timing of application, poor dosages and limited knowledge on scouting pests and decision making largely contribute to ineffectiveness of insecticides. Insecticides application therefore should be rotated in order to lower insect pest abundance.