BIOLOGICAL CONTROL OF PYTHIUM APHANIDERMATUM CAUSING DAMPING OFF DISEASE IN ETHIOPIAN KALES

Abstract

Damping-off disease caused by Pythium aphanidermatum has the potential to cause severe loss in greenhouse and field grown vegetables. P. aphanidermatum is common in soils from all climates, and capable of surviving for long periods without a host. In Kenya, this disease is mainly controlled through application of synthetic fungicide. The negative effects of this chemical has necessitated the search for an environmental and health friendly management method. Therefore study was undertaken to determine the efficacy of Bacillus subtilis BS-01 and Trichoderma asperellum TRC-900 against damping off in Ethiopian kale. B. subtilis, T. asperellum and combination of the two microorganisms were applied as seed coat. The coated Ethiopian kale seeds were planted on pythium aphanidermatum inoculated media. Pre and post emergence damping off incidence were observed. In B. subtilis, T. asperellum and combination of the biological control agents disease incidence of 16.9% - 29.8% compared to control which had 60.6%. The incidence of Post- emergence damping off reduced to range of 11 -25.4%, and control had an incidence of 64.8%. Damping off disease incidence in the T. asperellum and B. subtilis combinations was significantly reduced compared to the B. subtilis and T. asperellum isolates alone. This study revealed that using mixtures of B. subtilis and T. asperellum can provide a potential control for damping off disease in Ethiopian kales.  Therefore utilization of Bacillus subtilis BS-01 and Trichoderma asperellum T-800 alone or in a combination as seed coat can offer a solution to control damping off disease.