author(s)
Mutaviri L and W Mubvekeri

abstract
Cotton is a crop that has for many years been grown across all farming levels. Thus, it has been grown from the smallholder communal farmer to the large-scale commercial farmers. The main aim is the cash that it brings back especially if pests, which are a major threat to its production, are well managed. Chief among these pests is cotton bollworm. The use of pesticides has been the main method used in most cotton pests including this troublesome bollworm. For Heliothis bollworm larva, there were significant differences at CRI, Matikwa and Dande (all at p<.001) in 2020-21 season while only Dande recorded significant differences (p<.001) in 2021 -22 season. Hurricane at 125 g/ha recorded similar levels to the standard Nemesis at 400ml/ha across all sites within the two seasons. Cyclone 75WP at 200g/ha recorded lower levels than standard but only comparable at Dande. Aketchi was also lower than Nemesis across all sites. Dande, Matikwa and Umguza recorded significant differences on Red larva (p=0.010. p<.001 and p<.001) in 2020-21 while only Dande recorded significant different results in 2021-2022 season. The purpose of this research was to test efficacy of the three pesticides Hurricane 500WDG, Aketchi 260SLand Cyclone 75WDG in their control of the three bollworms Red, Heliothis and Spiny bollworms. They were tested at three different levels each. Hurricane levels were; 75g, 100g and 125g. Aketchi levels were; 300ml, 400ml and 500ml/ha while Cyclone was tested at 100g, 150g and 200g/ha respectively. These were compared to Nemesis (a standard) at 400ml/ha. The trial also had a no control treatment where no insecticide was applied. The eggs and larval counts of bollworms as well as predators were the main measurements. Data was transformed using the square root transformation of (x + 3/8) if that did not follow the normal distribution. Analysis was done using Genstat 14th Edition. Means were separated using Fisher’s Protected LSD in ascending order.