Effects of honeybee pollination and other insect pollinators on increasing the seed yield and germination capacity of carrot (Daucus Carota L.) in the central highlands of Ethiopia

The main objective of this study was to assess the effects of honeybee pollination and other insect pollinators on the seed yield and germination capacity of the Daucus carota variety Haramaya I in the Central Highlands of Ethiopia for two consecutive years (2023-2024). Carrot seeds were initially sown in nursery beds and later transplanted into planting plots, following standard agronomic practices. Three pollination treatments were tested: open pollination, honeybee only pollination, and pollinator exclusion (self-pollination). Each treatment was replicated three times in a randomized complete block design. Open pollination Carrot variety, Haramaya I, resulted in an average seed yield of 561.97 ± 41.08 kg/ha, which was slightly greater than the 559.22 ± 42.17 kg/ha from honeybee only pollination. The statistically insignificant difference indicates that honeybees are efficient pollinator compared to other insect pollinators. Excluding pollinators (Self-pollination) led to a significant drop in seed yield (144.45 ± 17.13 kg/ha) of carrot variety, Haramaya I, highlighting their vital role in seed production. Compared to the low yield observed under self-pollination, seed yield increased by 287.14% with only honeybee pollination and by 289.04% with open pollination. This demonstrates the vital role of pollinators in enhancing Carrot yields. Seed germination rates were also higher under open (96.10% ± 3.1) and honeybee only (92.5% ± 2.8) pollination than under self-pollination (40.53% ± 2.31). In addition to honey bees, other important pollinators include Eristalis spp., Meliponula beccarii, Lamprima aurata, Vanessa cardui, and Vespula germanica. These findings highlight the critical role of insect pollinators, especially honey bees, in carrot seed production. Therefore, it is recommended that honeybee colonies be placed near carrot variety Haramaya I fields during flowering to increase pollination, yield, and seed quality.