Effects of Agro net cover and companion planting with basil (Ocimum basilicum l.) on whitefly (Bemisia tabaci gennadius) infestation, yield and quality of tomato (Solanum lycopersicum l.)

Abstract

Tomato (Solanum lycopersicum L.) is a major vegetable crops, and is ranked second at 14% of total value of exotic vegetables produced in Kenya after potato with a value of 55%. It is predominantly grown by small to medium scale growers in open fields. However, open field tomato production faces many challenges including weather extremes, diseases and insect pests. The whitefly (Bemisia tabaci Gennadius), is one of the major pests of tomato capable of causing up to 80% loss in yield. To address the whitefly problem, most growers indiscriminately use synthetic insecticides. This however, is known to impact negatively on the environment, human and other natural pest management systems. The main objective of this study was to determine the effectiveness of agronet covers and companion planting with aromatic basil (Ocimum basilicum L.) as an alternate whitefly management strategy on tomato; and how the use of these treatments would impact on yield and quality of the crop. The study consisted of two trials of open field tomato production experiments at the Horticulture Research and Training Field, Egerton University, Njoro (Kenya); each followed by a tomato quality determination experiment in the laboratory. A Randomized Complete Block Design (RCBD) with six treatments replicated five times was used for the open field tomato experiment. Completely Randomized Design (CRD) with six treatments replicated three times for the quality determination experiment. Data collected included tomato plant growth and yield parameters, whitefly infestation and quality aspects of tomato fruit. Data collected was subjected to Analysis of Variance (ANOVA) at P≤0.05 level of significance and means separated using Tukey’s honestly significant difference (Tukey’s HSD) test at the same probability level. Results obtained showed that, agronet cover and companion planting with basil resulted in significant reduction in whitefly population, improved growth, yield and postharvest quality of tomato compared to the control treatments. Better reduction in whitefly population and increase in growth, yield and postharvest quality of tomato obtained when the two treatments were used in combination. Among the tomato-basil planting arrangement, planting a row of basil in-between adjacent rows of tomato proved more beneficial compared with basil was surrounding tomato plants from outside. Findings of the study demonstrate the potential of using agronet covers and/or companion planting as part of an integrated pest management strategy in tomato production leading to environmentally safe and affordable tomato culture while maintaining high yield and quality of the produce.