Biological control of fusarium yellows on beans caused by fusarium oxysporum schl. f. sp. phaseoli kendrick & snyder using organic amendments locally available in Kenya

Abstract

Coffee hulls and farmyard manure which are locally available were found to be effective in controlling Fusarium yellows in greenhouse experiments in Kenya. An attempt to establish optimum levels of soil amendment with coffee hulls in the greenhouse indicated that only very high levels of the ratio 2:1 w/w (soil: coffee hulls) give effective control. Lower levels reduced the disease significantly but not completely.

Nitrogen deficiency, characterized by the yellowing of leaves at high levels of coffee hulls amendment, was observed. This was later confirmed by leaf analysis for total nitrogen which was lower in the plants whose soils were amended with coffee hulls than those without amendment. The C/N ratio of coffee hulls was also shown to be over 90.