Biological Control of Angular Leafspot of Common Bean: Biological Control of Angular Leaf Spot of Common Bean (Phaseolus Vulgaris L.)

Among the bean diseases angular leaf spot (ALS) caused by Phaeoisariopsis griseola is a major constraint to production in the tropics and subtropics, and causes considerable yield losses. The effectiveness of the available methods for control of angular leafspot, which include cultural practices, use of chemicals and resistant varieties is limited by the ability of the pathogen to survive in plant debris for a long period of time, high costs of fungicides, lack of expertise and the health hazards involved, and the high pathogenic variability occurring in P. griseola. Therefore, there is need to develop an effective and alternative disease control approach. The strategy most likely to be effective in the control of angular leaf spot is integrated disease management utilizing resistant varieties, natural fungicides and appropriate cultural practices. Use of antimicrobial plant extracts in the control of ALS is an environmentally friendly option because plant extracts are biodegradable and therefore there is no fear of the breakdown products accumulating in the food chain.