Field evaluation of pollinator preference for selected vegetable crops

Pollinators are a key component of biodiversity providing vital services in the ecosystem. The loss of floral forage resources has caused a steady decline in their abundance and diversity. Intercropping is known to control pests and increase crop yield. However, information on intercropping crops attractive to specific a pollinator with crops dependent on that specific pollinator is lacking. This study aims at selecting vegetables attractive to pollinators. Six vegetables (sweet potato, cowpea, green beans, mustard, chickpea, and eggplant) were planted in a RCBD with 4 replications. Data collection included insect abundance and diversity using vacuum sampling, direct visual counts and pan traps. Plant attributes (pollen quantity, nectar volume and concentration) were determined. Pollinator diversity and abundance varied significantly (P < 0.05) between crops. Cowpea attracted most pollinators wasps (3.93 ± 0.39) ˃ bumble bees (1.01±0.14) ˃honeybees (0.41±0.08) ˃ sweat bees (0.14±0.07). Overall, pollinator abundance was higher on cowpea ˃ sweet potato ˃ green beans ˃ eggplant ˃ chickpea > mustard. Nectar production was highest on sweet potato (16.45 ± 0.99µl/flower) which attracted the highest bumblebees (4.45 ± 0.35), followed by cowpeas (10.96 ± 0.76µl) which attracted the most honeybees (0.41 ± 0.08). A significant correlation (r = 0.425, p < 0.01) was observed between nectar volume and pollinator abundance. Chickpea and mustard recorded the highest concentration (30.96 ± 0.19 Brix%) and (30.11 ± 0.23 Brix%) respectively and attracted no pollinators. We discovered pollinator-attractive vegetables for intercropping that can boost yield when grown with pollinator-dependent crops.