Evaluation of heat treatment and bio-priming of cowpea seeds for the management of fusarium wilt disease in the screen house

Abstract

Fusarium wilt is one of the most devastating diseases of cowpea. The pathogen, Fusarium oxysporum f.sp. tracheiphilum is soil and seed-borne. A non-chemical approach was designed for the management of the disease in the present study. Hot water (physical) at three temperatures, 40 50 and 60°C, and Trichoderma viride (biological) at 10 6 spores/ml were evaluated singly and synergistically in the laboratory. The duration of exposure to hot water was 5 min, after which seeds were allowed to cool followed by priming in sterile water (sole hot water treatment) or T. viride (synergistic physical and bio-control) medium in Petri-dishes for 72 h. The control consisted of seed treated with water at ambient temperature, while the standard check was seeds dressed with Mancozeb fungicide. Both were primed in a sterile water medium. Nine treatments were evaluated in all. Germinated seeds were transplanted into plastic pots containing soil infested with F. oxysporum at 10 6 spores/ml in the screen house. The experimental layout was completely randomized design and data collected were subjected to statistical analysis and mean separation. Results showed that seeds treated with 50°C hot water only had the highest germination percentage, 96.66%, and seedling vigour, 460.98. Disease incidence and severity values were least in seeds treated with synergistic hot water at 50°C and priming in T. viride medium. The highest number (77.33) and weight (13.41 g) of seeds were also recorded for the same treatment, while the least, 18 and 3.60 g were obtained from control. Integrated use of hot water (50°C) and bio-priming in T. viride medium can be recommended for use in the management of fusarium wilt disease of cowpea.