Effect of Angular Leaf Spot Disease on Bean Inter-cropped with Maize in Foumbot and Bambili, Cameroon

Abstract

The ability to increase beans output at local levels is often hindered by farmer’s ability to control angular leaf sport disease caused by Phaeoisariopsis griseola, in the field. Studies were carried out in Foumbot and Bambili, using a Randomized Complete Block Design (RCBD) with four treatments and four replications in order to assess the impact of intercropping on angular leaf spot disease. Two varieties of bean were used (white dwarf and red dwarf marked beans). Treatments one and two consisted of mono-cropping of white dwarf and red dwarf marked bean varieties while treatments three and four consisted of the same varieties of beans inter-cropped with maize respectively. The data on disease incidence, disease severity, number of pods and pods weight were recorded in mono-cropped and inter-cropped fields. Pathogenicity assessment was carried out in the screen house by inoculating healthy plants with fungal isolate (3×104 spores / ml), during which the lesion diameter was measured. Beans varieties inoculated with spores’ suspension of P. griseola in the screen house showed symptoms identical to that of infected plants in the fields. The results obtained for disease severity and yield revealed that there was a significant difference (Pd”0.05) on the different treatments and in the different fields. The best yields and least disease severities of beans were observed in fields inter- cropped with maize because wind and rainfall splashes were intercepted by the plant which is not a host to P.gliseola thus a reduction of disease in the inter-cropped fields’ plant which is not a host to P.gliseola thus a reduction of disease in the intercropped fields. This shows that intercropping beans with maize can be used as a best management option to control angular leaf spot disease for the two varieties of beans used in this study.