| The major root rot pathogens of beans in the principal production area of Kabale, Uganda were Fusarium solani f.sp. phaseoli, Rhizoctonia solani, and Pythium spp. These pathogens often occurred together on the same beans and in all possible combinations resulting in root rot complexes. Bean germplasm components, selected from local varietal mixtures were found to be susceptible to root rot pathogens compared to improved bean genotypes included in the screenhouse tests. The bean germplasm 'RWR 719' exhibited a consistent tolerant reaction to root rot pathogens.;The influence of a green manure of Acanthus on root rot severity and yield of local bean varietal mixtures treated or untreated with metalaxyl and chloroneb fungicides, was evaluated in 13 fields in southwestern Uganda. Beans growing in Acanthus-amended plots had significantly lower root rot severity, higher stand, and highest seed yield. Seed treatments did not reduce root rot severity, but increased yield in unamended plots.;A survey of farmers was conducted in December, 1994 in the Kabale and Kisoro Districts to learn about the use of organic amendments and other soil management and pest control practices. A follow-up interview was conducted in April, 1996 to assess the acceptability of Acanthus green manures by farmers. Land shortages and small farm size were limiting factors in the application of effective cultural practices. Major constraints to bean production cited by farmers were heavy rain, drought, insect pests, and rats. Participating farmers developed positive opinions in using Acanthus sp. as a green manure, as they noted improved soil fertility, enhanced plant growth, and increased yield. They made several suggestions for promoting Acanthus use.;Various organic soil amendments including Acanthus pubescens, Calliandra calothyrsus, Cassia spectabilis, Leucaena diversifolia, Tithonia diversifolia, cow dung, sorghum straw, banana and vegetation composts were evaluated for their effectiveness in suppressing root diseases and increasing bean yield. The incorporation of a green manure of A. pubescens reduced root rot severity of beans under field and screenhouse conditions. Green manures of C. calothyrsus, L. diversifolia, and C. spectabilis were also beneficial. Beans growing in Acanthus-amended plots also showed greater vigor and higher yields. |
