Response of tomato genotypes to Meloidogyne javanica and Fusarium oxysporum f.sp. lycopersici co-infestation under glasshouse conditions

Tomato (Solanum lycopersicum) is an economically and nutritionally important vegetable crop grown worldwide. However, its yield in Ethiopia is very low as compared to the world and African average yield. Root-knot nematodes and Fusarium wilt are among the most economically important pathogens of tomato. A study was initiated with the objectives of determining the interaction effect of M. javanica (MJ) and F. oxysporum f. sp. lycopersici (FOL) disease complex and evaluating the response of selected tomato genotypes against this disease complex under glasshouse condition. A glasshouse experiment was laid out in a factorial randomized design with 18 treatment combinations of three tomato genotypes (Assila, Cochoro, Marmande) and two pathogens (MJ and FOL) with four replications. At four true leaf stage, tomato seedlings were inoculated with the suspension of MJ at a rate of 3000 second-stage infective juveniles (J_2) and 10 ml FOL suspension (1x10^6 spores per milliliter) per pot around the root rhizosphere one week after transplanting except the control which was not inoculated. The result revealed that concomitant inoculation of MJ and FOL (NF) followed by MJ first and FOL ten days after inoculation (N1F2) was found to be highly significant in reducing the tomato growth, biomass and pathogen related parameters compared to the un-inoculated control or single pathogen inoculated treatments. Among the three tomato genotypes evaluated, Assila was found to be moderately resistant as measured by the lower number of root galls and egg-masses per plant compared to the susceptible Marmande genotype. Hence, further study is required to evaluate the performance of Assila genotype in hot spot areas of Meloidogyne species and Fusarium species infested farmer’s field conditions.