Interaction of Root-knot Nematode and Cucumber mosaic virus Infection on Growth and Yield of Tomato

Abstract

The effect of single and combined infections of a root-knot nematode, Meloidogyne incognita and Cucumber mosaic virus (CMV) on the growth and yield of tomato (cv. Roma VF and UC82b) was investigated. This was with a view to determining the pattern of interaction of M. incognita and CMV on selected tomato cultivars. The study consists of one screenhouse experiment and two field trials with the following treatments applied for four days after transplanting of tomato seedlings: inoculation of plant roots with 5,000 eggs of M. incognita per plant only; mechanical inoculation of primary leaves with crude CMV sap only; inoculation of plant roots with 5,000 eggs of M. incognita two days before inoculating leaves with crude CMV; inoculation of CMV sap two days before inoculating the plant roots with 5,000 eggs of M. incognita; simultaneous inoculation of primary leaves with crude CMV sap and 5,000 eggs of M. incognita, and uninoculated control. Data collected on plant biomass, fruit yield and nematode population density at 90 days after planting were subjected to analysis of variance and treatment means separation using Least Significant Difference at 5% level of probability. Infection of M. incognita and CMV simultaneously performed better in plant growth parameters than single infection of CMV or M. incognita both in the screenhouse and in the field. Inoculation of M. incognita before CMV inhibited virus infection and vice versa both in the screenhouse and in the field. Combined infections of M. incognita and CMV resulted in a higher plant biomass and fruit yield than single infection. The study established that either of the two pathogens could be used to suppress the effect of the other on selected tomato plants.