Abstract
Onion (Allium cepa L.) is a highly cross pollinated crop that needs insect pollination (entomophily) for optimum seed set. In the present study, more than 120 insect species were noted to visit onion flowers, out of which fifty-nine species were collected through in-situ sampling technique and identified up to species level. The Indian bee (Apis cerana indica) was the most abundant insect pollinator visiting onion flowers in the study location. The pollination behaviour and foraging activity of A. c. indica were assessed, and the pollen foragers were observed to be swift flyers visiting a significantly higher number of flowers per minute during the peak flowering period and spending less time per flower (3 seconds) to collect nectar from deep seated nectaries of the flowers. The seed yield enhancement assessed through entomophily and artificial pollination methods showed that the open pollinated flowers recorded the highest yield statistically, followed by A. c. indica and A. mellifera pollinated flowers. However in artificial pollination treatments, sponge puff pollinated flowers recorded significantly high seed yield per hectare and percentage seed set per umbel, followed by camel brush, hand gloves (cloth) and hand gloves (rubber). In conclusion, all the cross pollination treatments were statistically significant on the closed pollination treatment concerning to the entire yield parameters calculated.