Comparative Efficacy of Garlic Clove and Castor Seed Aqueous Extracts Against the Root-Knot Nematode, Meloidogyne Incognita Infecting Tomato Plants

A greenhouse experiment using aqueous extracts of garlic (Allium sativum) cloves and castor bean (Ricinus communis) seeds, to control root-knot nematode, Meloidogyne incognita on tomato cv. Super strain B, was conducted. The plant materials were diluted with distilled water; the concentration was 10 g/100 ml. Four-week old tomato seedlings were planted in pots and arranged in a completely randomized block design for a treatment of five replicates. Approximately 2,000 juveniles of root knot nematode were pipetted around each plant. The botanical extracts were either soil drenched or foliar sprayed, for each pot. Cadusafos 10G (Rugby) as a nematicide, and non-treated pots served as the control. Results showed that tomato is susceptible to M. incognita infection. Botanical extracts were more effective and significantly (p ≤ 0.05) reduced nematode criteria including number of galls and egg masses on roots of tomato and number of juveniles in roots and soil, compared to nematicide and non-treated plants. In general, a high dilution of the tested materials caused higher increases in lengths and weights of shoots and numbers and weights of fruits than those occurred by a low dilution.