Loss Assessment Study on Haricot Bean due to Anthracnose

Abstract

Bean anthracnose, caused by Colletotrichum lindemuthianum Sac. and Magn. is widely spread and economically one of the most important diseases of haricot bean in Ethiopia. To evaluate severity of this disease and its effect on yield, field experiments were conducted at Ambo (on-station) and Meki (on-farm) between 1992 and 1995 crop seasons, using the susceptible commercial bean genotype ‘Mexican 142’. Varying levels of disease severity and epidemics conditions were maintained in the experiment by spraying a systemic fungicide, benomyl, at the rate of 0.4 kg ha-1 at different intervals. Highly significant differences in disease level and yield were recorded between sprayed and unsprayed plots. Severity of anthracnose varied between 11.8% and 83.5% in the on-station and between 17.2% and 76.6% in the onfarm trials. This high disease severity resulted in mean yield losses of 62.4% in onstation and 67.2% in on-farm trials. There was an estimated net gain of approximately Birr 2376 ha-1 from on-station trial whereas in the on-farm trial, the net gain by controling anthracnose with benomyl was Birr 1915 ha-1.