A field evaluation of nine chemicals was conducted at Cotton Research Station Kibos for their efficacy against bollworm and cotton stainer species attacking cotton in Kenya. Based on the yield and percentage stained seed cotton, Decis'Triazophos, pp 321 Karate and Baythroid and Decis were the most effective insecticides in 1985 and 1986 respectively. However, there was no consistency in results of performance of insecticides tested against cotton insects in the 2 years. The apparent poor performance of most insecticides tested against cotton insects was attributed to fixed insecticide spray schedule which resulted in superfluous and often mistimed chemical applications. It is therefore necessary to establish damaging threshold(s) of major cotton pests in this country so that chemicals can be efficiently used to control them with minimum adverse effects on our environment.
