Effect of insect pollinators and natural enemies on common bean (phaseolus vulgaris l.) growth and yield in Arusha, Tanzania

Abstract

This study examined the potential of pollination from stingless bees in common beans, the effects of natural enemies on aphid infestation in common bean plants and the effect of natural enemies on growth, yields and yield components of common beans. Common beans of Lyamungo 90 variety were used as a test crop under natural rain fed condition throughout the growing season in a randomized block design experiment that had seven treatments replicated four times. Normal agronomic practices such as tilling, planting and weeding, coupled with the introduction of stingless bees and ladybird beetles in the pollination and pest control activities were employed. Analysis of Variance was used to determine mean aphid incidence/severity and LSD was used to separate means at p=0.05 level of probability. Results showed that there was a significant increment of pods per plant (6.278), seed per pods (3.011) and total yield per hectare (2164.328) in stingless bee pollination cages and significant aphid control by the action of ladybird beetles. This study calls for enhancements of research on ecosystem services under natural field contexts in order to obtain enough data to support adoption of the interventions to especially small scale farming communities in developing countries.