Influence of Niger plant (Guizotia abyssinica l.) on growth and development of common beans (Phaseolus vulgaris)

Plants affect other plants growing in their vicinity either positively or negatively by producing exudates known as secondary metabolites. These secondary metabolites, also known as allelochemicals, can be harnessed and utilized in controlling the growth of weeds, among other uses. The current worldwide demand for cheaper, more environmentally-friendly weed management technologies has motivated a number of studies on the allelopathic interaction between crops and weeds. Niger plant (Guizotia abyssinica) has been observed to have allelopathic effects on certain weeds. Studies have been done on the effect of allelochemicals on weeds but little on crops that coexist with the weeds. Treatments included weedy check (no weed control measure), weed free, Niger plant intercrop and all weeds except Niger plant. Three varieties of beans (Rosecoco, Mwitemania and Mwezi Mbili) were used. The experiment was a 3 x 4 factorial laid out in Randomized Complete Block Design (RCBD) with three replicates. Data were collected on stand count at two weeks, plant height at 50% flowering, number of pods per plant, number of seeds per plant and stand count at harvesting. Data analysis was done by ANOVA in Genstat and means separated using Duncan’s Multiple Range Test (DMRT). Results showed that Niger plant positively influenced the growth and development of beans. Niger plant can therefore safely be intercropped with beans without compromising its growth and development. Further research should be carried out on the influence of Niger plant on bean yield.