Effect of Meloidogyne incognita and Fusarium oxysporum f. sp. lycopersici on tomato varietal growth under Ghanaian field conditions

Abstract

The excessive build-up of soil nematodes and uncontrolled spread of fungal diseases contribute to low yields in tomato (Solanum lycopersicum L.) production. The objective of this study was to investigate the pathogenicity of Fusarium oxysporum f.sp. lycopersici and Meloidogyne incognita on growth, yield and wilt severity in tomato varieties. A factorial experiment was laid out in a randomised complete block design (RCBD), with three replications, on two fields, namely University of Ghana, Legon farm and at the National Service Demonstration Farm at Papao both in Ghana, from July 2018 to June 2019. Two tomato varieties, namely Mongal F1 and Petomech were used for evaluation. Fusarium inoculum of 1.3×106 cells per 5 mL suspension was inoculated in the experimental plots naturally infested with Meloidogyne incognita, at 7, 14, and 21 days (NF7, NF14, NF21), after transplanting tomato seedlings into the fields. Wilt severity was higher in the Petomech plants compared to Mongal plants, for all treatments. Wilt incidence was greater than 70% in the Petomech plants that received the treatments NF7, NF14, and NF21 in both experimental sites, respectively. Plants in the control plots had the least wilt incidence and severity among the two varieties in both sites. Mongal and Petomech plants without Fusarium inoculation had lower wilt incidence and severity compared to those that received only Fusarium inoculation. Yield was higher in the Mongal plants than in the Petomech plants. Galls scores were zero in the Mongal F1 plants for all treatments applied, in both experimental sites. Fusarium oxysporum f. sp. lycopersici and Meloidogyne incognita increase wilt severity in tomato plants when both pathogens coexist in the soil.