Insect Pollinator Diversity and Their Influence on Yield and Quality of Capsicum annuum Linné (Solanaceae), Machakos, Kenya

Capsicum annuum (L.) yields have remained low due to poor quality fruits in developing countries such as Kenya, which could be attributed to inadequate insect pollination among other factors. The present study was conducted after the short and long rain seasons in 2018 to assess the diversity and abundance of insect pollinators of C. annuum and to determine their influence on yield. The experiment was laid out in a Randomized Complete Block Design with bagged and un-bagged pollination treatments. Insect pollinator assessment was conducted between 07:00 hours to 21:00 hours for one month during each season. Yield and quality were compared between the pollination treatments. During the entire study 13 insect pollinator species (3 orders, 7 families) were recorded onC. annuum flowers. Apis mellifera was the most abundant insect pollinator during the two seasons. The highest species diversity was recorded after the long rain season (H' = 1.85). With respect to time, species richness was the highest in the afternoon after the short rains and the highest in the morning after the long rains. The average yield parameters from both seasons showed that open pollination treatments had increased fruit weight (66.5%), seed weight (54.5%) fruit length (28%) and fruit diameter (30%) when compared to treatments bagged throughout. Findings from this study have shown that insect pollinator diversity varies seasonally and significantly influences the yield and quality of C. annuum. This calls for the need to practice sustainable agriculture so as to conserve insect pollinators of C. annuum for improved vegetable production in semiarid lands of Kenya.