Electrolyzed fertilizer solution (EFS) was produced by passing an irrigation solution through an electrolization chamber in order to suppress fungal disease caused by Fusarium oxysporum f. sp. cubense race 4 (Foc4) infecting banana plantlets. In the laboratory, EFS was prepared by electrolyzing solutions containing different amounts of potassium chloride and potassium nitrate. The results indicated a significant reduction in the conidial densities of Foc4 which was from 10 ⁶ spores · ml ^–1 to a maximum of 10 ^1.3 spores · ml ^–1 and depended on the concentration of components in the input flow. Eventually the EFS produced from the lowest one was chosen to treat banana plantlets. Greenhouse experiments gave contradictory results of inoculated plantlets irrigated with or without EFS. The untreated banana plantlets virtually showed symptoms of infection such as discoloration of cross-cut corms, rapid wilting and dying within 60 days, while the treated ones kept their shapes and grew normally. The drastic fall in the microbial population in the rhizosphere of treated plants confirmed the activity of oxidation agents which is the major mechanism of disease suppression. The results suggest that further studies of EFS in the field as a potential technique in fighting Panama wilt in the banana industry are necessary.

This paper presents a preliminary report of Fusarium wilt of Roselle in the Nigerian savanna. Soil and plant samples were collected from eight experimental plots where plants showed Roselle wilt symptoms. Samples were analyzed for the presence of nematodes and wilt pathogens. The wilt causative organism Fusarium oxysporum was isolated together with nematodes of different genera. However, nematodes of the genus Helicotylenchus, Scutellonema and Hoplolaimus appeared to occur in higher densities than the others.