SOIL AND SEED TREATMENT WITH Bacillus Thuringiensis AND AVOCADO (Persea Americana) SEED POWDER AGAINST FUSARIUM ROOT ROT OF OKRA

Abstract

Disease management strategies using synthetic chemicals are expensive, hazardous and environmentally unfriend ly and have necessitated the search for alternatives in biological agents with antimicrobial properties. This re search was aimed at assessing the effectiveness of Bacillus thuringiensis and avocado seed powder applied either as soil amendments and/or seed coatings on Fusarium root rot of potted okra. Fusarium oxysporum isolated from diseased okra plants was used to inoculate the pots. The experiment was a completely randomized design (CRD) replicated eight times. Data were collected on percentage germination, disease incidence and plant growth param eters such as shoot weight, root weight, shoot length and root length. Results showed significant (P = 0.002) differ ence among treatments with the hybrid seeds having the highest percentage germination of 94% followed by soil treated with avocado seed powder (85%) and their effect differed significantly from the control. In terms of dis ease incidence, hybrid seeds, seed coating or soil treatment with avocado and soil treatment with Bt all controlled the disease giving incidence values of 26%, 25%, 18% and 16%, respectively, which differed from the control pots (41%). Shoot length was significant (P = 0.049 and P = 0.007) at both assessments where hybrid seeds constantly maintained the tallest plants. Since the treatments suppressed the incidence of root rot disease, the use of these treatments is advocated for effective management of Fusarium root rot disease.