Potency of plant-derived biological nematicides on root-knot disease of tomato, Lycopersicon lycopersicum (L.) Mill

Abstract

The aim of this research was to evaluate the effectiveness of plant-derived biological nematicides in the management of root-knot nematode disease of tomato. A piece of land measuring 8 m × 54 m was ploughed and raised beds were the experimental plots. The land was divided into 4 blocks, each block comprising 12 treatments and 4 replicates with a total of 48 experimental plots were fitted into randomized complete block design (RCBD). The experiment was carried out at the Teaching and Research Farms, Faculty of Agricultural Sciences, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria (Longitude 40E and Latitude 8010N) during 2018 planting season. 20 g macerated root gall of Celosia was applied to tomato root rhizosphere (inoculation). The plant-derived biological nematicides that were assessed on root-knot nematode disease of tomato, UC8 cultivar, include the leaf water extract of neem, castor, wild sunflower, cleome, siam weed, phyllanthus, nitta, tobacco, lantana and calotropis, mixed with black soap, at rate of 9:1 v/w. The black soap and distilled water served as adjuvant and solvent respectively, and as the control experiments. The results showed that the root galling and soil population of root-knot nematode were significantly reduced with consequent enhanced growth and yield of tomato in the plots treated with plant-derived biological nematicides, compared with the tomato in the control experiments. The study has demonstrated that the use of plant-derived biological nematicides can be effectively explored in the management of root-knot nematode disease. The application of plant-derived biological nematicides is therefore recommended for sustainable management of root-knot nematode disease in tomato production.