Abstract

Development of diseases in cultivated crops depends on the complex inter-relationship between host, pathogen and prevailing environmental conditions. The significant role of nematodes in the development of nematode–fungus interaction is demonstrated in many crops throughout the world. However, there is scanty research information in Ethiopia. Therefore, the main objectives of this study were to: (i) investigate the effect of Meloidogyne incognita (MI)-Fusarium oxysporum f.sp. lycopersici (FOL) interaction on selected tomato genotypes based on their order of inoculation and (ii) evaluate the reaction of selected tomato genotypes against the MI-FOL interaction. The greenhouse experiment was laid out in a completely randomized design (CRD) factorial with four replications. Three-week-old tomato seedlings were inoculated with MI suspension at a rate of 3000 second-stage juveniles (J2) and 10 ml FOL suspension (3x106 conidia/ml/pot) around the root rhizosphere. Tomato growth, biomass and pathogen related data were recorded starting first week after inoculation to eight weeks of post inoculation. The result revealed that simultaneous inoculation of MI and FOL (NF) and FOL 10 days after MI (N1F2) was found significantly (p ≤ 0.05) reducing tomato growth, biomass and pathogen related parameters compared to single pathogen or un-inoculated control. Among the three tomato genotypes tested, Assila was moderately resistant as measured by the lower number of root gall and egg mass per plant, that it could be of a good choice to manage this disease complex or interaction. Performance evaluation study at MI-FOL hot spot farmers’ field should be investigated in the near future.

Key words: Fusarium oxysporum f.sp. lycopersici, Meloidogyne incognita, resistance, management, synergistic effect and tomato varieties