Comparative assessment of the efficacy of emamectin benzoate 5.7% and 5 % on the control of tomato fruit borer on tomatoes in Uganda

Abstract

In Uganda, average tomato yield is 4,846.3 kg/acre lower than the potential yield of 6000kg/acre mainly due to attack by various insects-pests including fruit borer, which is one of the most serious pests responsible for the yield gap of 12-ton ha-1. Majority of farmers, about 97.5% use chemical sprays (pesticides) to manage the pest. However, the unselective use of synthetic chemical pesticides to control this pest often result in development of insecticide resistance which can be overcome by rotating the chemicals. One of such chemicals is emamectin benzoate containing pesticides that have been found to be useful in the control related insect pests but has however, never been tested under Ugandan conditions. To prove this, field experiments were conducted in Soroti at Busitema University Arapai Campus, and Bulegeni farm a satellite of BugiZARDI during the period April to august 2022 to evaluate the efficacy of different rates of BENTIL (emamectin benzoate 5.7%) compared with PORCELENE (emamectin benzoate 5%) against Helicoverpa armigera, the major insect pests of tomato. At both sites the treatments included BENTIL at three levels (5g/20ltr, 10g/20ltr, and 15g/20ltr), and PORCELENE (20g/20ltr) used as Positive control. Plots with no treatments were used as negative control. The treatments were applied thrice at 10 days’ interval from flowering to maturity i.e. at early, mid and late fruiting stages parameters collected were infestation, severity, yield parameters like number of flowers and flower buds, and the yield weight. The experimental results showed that BENTIL at a rate of 15g/20ltr of water gave the best result with low infestation levels, low severity percentage and registered the highest yield per acre followed by the PORCELENE and BENTIL 10g and there were variation iv results in Soroti and Bulambuli. On the other hand, the negative control showed the highest level of infestation, severity levels and with the least yield per acre. Conclusively based on the results EB5.7 had great impact on the management of the pest and specifically 15g EB5.7, based on the performance is commended.