Evaluation of Insecticides and Fungicides for the Management of Insect Pests and Diseases of Tomato (Solanum lycopersicum L.)
Studies comprising a survey conducted in Agogo in the Ashanti region to gather information on farmers’ perceptions on tomato production and field experiments conducted in 2012 and 2013 at the Plantation Crops Section of the Department of Crop and Soil Sciences of the Kwame Nkrumah University of Science and Technology, (KNUST) were undertaken to evaluate the efficacy of two insecticides (Lambda Super and Cymethoate) and two fungicides (Shavit F and Kocide 2000) for the management of insect pests and diseases of tomato. Results from the survey showed that males dominate tomato production in Agogo. Majority (74.3 %) of the farmers aged between 31 – 50 years and most of them had no formal education. Majority of them obtained their seeds from agrochemical shops. The survey also revealed that whiteflies, Bemisia tabaci (Gennadius); Thrips, Thrips tabaci (Lindeman); Aphids, Aphis gossypii (Glover); and Tomato fruitworm, Helicoverpa armigera (Hubner) were the most important insect pests that attack tomato in the area. Septoria leaf spot, Blight, Fusarium wilt and rot were identified by farmers as the major diseases of that affect tomato. About 45.7 % of the farmers reported that pesticides were not effective, with 48.6 % of them reporting of their effectiveness. The field experiments had the following treatments: Lambda Super 2.5 EC (Lambda-cyhalothrin a.i.) at 1.5 ml / 0.5 L of water; Cymethoate Super EC (Cypermethrin & Dimethoate a.i.) at 0.25 ml / 0.5 L of water; Control, (water only); Shavit F 71.5 WP (Folpet + Triadimenol a.i.) at 6.25 g / 2.5 L of water and Kocide 2000 (Copper Hydroxide a.i.) at 100 g / 15 L of water. vi In the experiment in 2012, there were no significant differences among the insecticide - treated plots and the control with respect to the densities of B. tabaci, A. gossypii, Liriomyza sp. and H. armigera. Cymethoate recorded significantly lower number of T. tabaci than the control. In the experiment in 2013, the control plots recorded significantly more aggregations of B. tabaci, H. armigera and A. gossypii than the Lambda Super and Cymethoate treated plots. There were no significant differences in the number of leaf miners, Liriomyza sp. and T. tabaci in the insecticides treated plots. In the experiment in 2012, there were no significant differences among fungicide treatments with respect to Blight, Fusarium wilt, Leaf mould and Tomato Yellow Leaf Curl Virus (TYLCV) disease. Significant difference was however observed in Septoria leaf spot between treatments. In the experiment in 2013, there were no significant differences among fungicide treatments with respect to the diseases. There were no significant differences among the insecticides and fungicides treatments with respect to number of fruits plant-1, mean fruits weight plant-1, mean % damaged fruits and mean yield (kg ha-1). No significant difference was observed among treatments with respect to mean shoot dry weight. The implications of these results were discussed.
A Thesis Submitted to the School of Graduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana, in partial fulfillment of the requirements for the Degree Of Master of Science In Crop Protection (Entomology), August-2013