Effect of rabbit urine foliar spray on whitefly population, tomato (solanum lycopersicum) yield and fruit quality

Abstract

Tomato (Solanum lycopersicum) is the second most important vegetable crop in the world after potato due to the growing awareness of its nutritional and health benefits. Whiteflies greatly contribute to low tomato yields in Kenya. Rabbit urine is both a bio-pesticide and as a bio-fertilizer. Therefore, the aim of this study was to determine the effects of rabbit urine foliar spray on whitefly population, yield and quality of tomato. The study was conducted inside a greenhouse at the Horticulture Research and Demonstration Field, Egerton University, Njoro from February to July, 2022 (trial 1) and August, 2022 to January, 2023 (trial 2). The experiment was set in a randomized complete block design (RCBD) with six treatments replicated four times. The treatments included: 0% v/v rabbit urine, 18.2% v/v rabbit urine, 25% v/v rabbit urine, 40% v/v rabbit urine, 100% v/v rabbit urine and 0.1% v/v Duduthrin 1.75EC. Individual plots were separated from each other by polythene films due to the volatile nature of the sprays. Data was collected on the following variables: whitefly populations, tomato yield, post-harvest fruit quality and repellent and toxicity effects of rabbit urine on adult whiteflies. Data obtained were subjected to analysis of variance (ANOVA) and treatment means separated using Tukey’s Honestly Significant Difference Test at P ≤ 0.05. Treatment 100% v/v rabbit urine recorded adult whitefly populations of as low as 0.7 and 0.8 whiteflies per plant at 42 DAT of trials 1 and 2, respectively. Repellence and mortality of adult whiteflies increased with increase in rabbit urine spray concentration. In trial 1, treatment 18.2% v/v rabbit urine registered the highest total marketable yield of 129.14 t ha-1. In trial 2, treatment 25% v/v registered the highest total marketable yield of 165.08 t ha-1. In both trials, treatment 100% v/v rabbit urine registered the lowest marketable yield of 82.63 t ha-1 in trial 1 and 44.59 t ha-1 in trial 2. Treatment 100% v/v rabbit urine registered the lowest fruit firmness of 2.23 KgF in trial 1 and 2.35 KgF in trial 2. However, treatment 100% v/v rabbit urine recorded the highest total soluble solids content of 3.55 °Brix and 3.45 °Brix in trials 1 and 2, respectively. Unlike fruit titratable acidity content, sugar acid ratio decreased with increase in rabbit urine foliar spray concentration. Therefore, 25% v/v rabbit urine foliar spray concentration is recommended for optimal whitefly control and improved yield and post-harvest quality of tomato.