Field evaluation of pollinator preference for selected vegetable crops

 
Pollinators are a key component of global biodiversity that provide vital ecosystem services. Their abundance and diversity have steadily declined and loss of floral resources has been a leading cause. Intercropping has been shown to increase crop yield. However, information on crops attractive to specific pollinators to intercrop with crops dependent on that specific pollinator is lacking. The goal of this study is to identify vegetables attractive to pollinators. Six vegetable crops (sweet potato, cowpea, green beans, mustard, chickpea, and eggplant) were planted in a RCBD with 4 replications. Data on insect abundance and diversity was obtained using vacuum sampling, direct visual counts and pan traps. Pollen quantity, nectar volume and concentration and chlorophyll content of the six crops were evaluated. Pollinator diversity was highest on cowpea with wasps (3.93 ± 0.39) ˃ bumble bees (1.01±0.14) ˃honeybees (0.41±0.08) ˃ sweat bees (0.14±0.07). Pollinator abundance was higher on cowpea ˃ sweet potato ˃ green beans ˃ eggplant ˃ chickpea and mustard. Nectar production was highest in sweet potato (16.45 ± 0.99 µl/flower) which attracted the highest bumble bees (4.45 ± 0.35), followed by cowpeas (10.96 ± 0.76µl) which attracted the most honeybees (0.41 ± 0.08). Chickpea and mustard recorded the lowest nectar volume, attracted no pollinators but recorded the highest nectar concentration (30.96 ± 0.19 Brix%) and (30.11 ± 0.23 Brix%) respectively. Our findings will provide vegetable growers information of vegetables attractive to specific pollinators that can be grown in an intercropping system with pollinator-dependent-crops for increase yield.