Effect of Integrated Management of Anthracnose (Colletotrichum lindemuthianum) on Plant and Seed Health of Common Bean in Hararghe Highlands, Ethiopia

Abstract

Bean anthracnose, caused by Colletotricum lindemuthianum (Sacc. & Magn.) is an important disease affecting common bean (Phaseolus vulgaris L.). Information on yield losses and management options addressing both seed and soil-borne inoculum sources of this disease is lacking in Hararghe highlands which produces common bean in large areas. The present study was undertaken to evaluate the effect of integrated management of bean anthracnose through soil solarization and fungicide applications on disease development, seed health and seed yield of common bean variety Mexican-142. Field experiments were conducted at Haramaya University main campus and Hirna Research Sub-Station in 2010 main cropping season. Soil solarization was integrated with mancozeb and carbendazim seed treatments, with foliar sprays of carbendazim at the rate of 0.5 kg/ha at 10 and 20 days intervals. The experiment was arranged in 2 x 3 x 3 split-split plot design with three replications. A total of 18 treatments were evaluated. There was significant difference in the anthracnose incidence, severity, infected pods per plant, infected seeds and AUDPC among treatments. Combined effect of mancozeb seed treatment with carbendazim spray at 10 day intervals and carbendazim seed treatment and carbendazim spray at 10 day intervals have reduced severity by 46.5% and 41%, respectively at Haramaya. Interactions of solarized soil with carbendazim foliar spray frequencies at 10 days interval reduced the number of infected pods per plant by 58% at Haramaya and 38.9% at Hirna. Seed treatments, foliar sprays and soil solarization alone as well as their interactions did not significantly affect pods per plant and seeds per pod at both locations. The combinations of solarized soil + mancozeb seed treatment + carbendazim foliar spray at 10 day intervals produced seed yield of 3.8 t h-1 at Haramaya and 3.6 t h-1 at Hirna over the control. In the results concluded that, the integration of soil solarization, seed treatments and foliar spray were found to be effective in reducing bean anthracnose epidemics and increasing yield. Extensive studies are recommended for detection of seed health and management options to enhance high quality of common bean production in these regions.