Nematicidal Effect of Some Botanical Extracts for the Management of Meloidogyne incognita and on Growth of Tomato

Abstract

Tomato (Solanum lycopersicum L.) is an important and widely grown vegetable crop all over the world. Although tomato is nutritionally and economically important, its production is constrained by biotic and abiotic constraints leading to poor marketable quantity and quality worldwide. Root-knot nematodes are one of the major pests affecting tomato production worldwide, especially, in the tropical and sub-tropical regions. Green house experiments were laid out in Complete Block Design (CBD) with a 3x7 factorial arrangement replicated three times carried out at the Department of Crop and Environmental Protection, University of Agriculture. The soil was sterilized before the experiment. Fresh leaves and seeds of Moringa oleifera, Ricinus communis  and Jatropha curcas were washed with tap water, 15 g  from each of leaves and seeds of the different botanicals was macerated separately in an electric blender at high speed for 4 minutes in 100 ml distilled water. The mixtures were passed through a Whatman filter paper number 1; the filtrates of the leaves/seeds were then collected. Three tomato varieties viz: Roma Vf, Rio Grande and UC82B were inoculated with approximately 5,000 freshly hatched second stage juvenile of Meloidogyne incognita, two weeks after transplanting.  Thirty percent aqueous extract each  of Castor, Moringa and Jatropha leaves and seeds was used, while double distilled water (0%) served as the control. Thirty ml of   each leaf and seed aqueous extract was applied, 48 hours after inoculation as soil drench. Application was done at 1 weeks intervals thereafter for a period of 16 weeks. Data collected include number of fruits per plant, root gall index, nematode reproductive factor, and final nematode population. The results showed that various Moringa oleifera, Ricinus communis  and Jatropha curcas leaves and seed extracts significantly (P<0.05) reduced root gall index, final population of M. incognita in the soil and nematode reproductive factor than the control. Application of the various treatments Moringa oleifera, Ricinus communis  and Jatropha curcas led to significant increase in mean number of fruits and mean fruit weight yield of all the three tomato varieties. Therefore, the application of leaf and seed aqueous extracts of Moringa, Jatropha and Castor will serve as good alternative for the management of root knot nematode Meloidogyne incognita.