Honey bees (Apis mellifera) pollination enhances watermelon (Citrullus lanatus) yield in Kibaha Tanzania

Honey bees are essential pollinators of the world’s food crops. However, information on the influence of honey bee pollination on watermelon yield is limited in Tanzania. This study assessed efficiency of honey bee pollination on watermelon yield. The study tested three improved watermelon varieties (Zebra F1, Candy F1 and Sukari F1) and three pollination environments: (Caged with Apis mellifera (CAM), Caged without insects (CW) and Open pollination (OP) in two seasons. The experiment was arranged in a split-plot design in randomized complete block design (RCBD) with three replications. Results showed no significant interaction between pollination environment and varieties. Significant difference was observed in the number of fruits per plant, fruit weight (kg), yield (t/ha) and number of mature seeds among pollination environments across all seasons (p ≤ 0.0001). These parameters were significantly lower under CW, while no significant difference (p > 0.05) was detected between CAM and OP. Honey bees showed similar preference among the varieties and its contribution to an average yield increase was about 90% compared to CW in all seasons. The study conclude that honey bees are important pollinators contributing significantly to watermelon yield. Therefore, conservation of honey bees is crucial for sustainable seeds and fruits production.