Floral biology and pollination ecology of onion (Allium cepa L.)

Abstract

Onion, an entomophily cross pollinated vegetable crop. The present study reports the details of structures, behaviour and biochemical aspects of onion flower. It takes 64-67 days to flower from the date of bulb sowing, remain flowering for next 40-45 days and 88-91 days to produce maximum number of open flowers. Anthesis occurs at 06-07 am and anther dehiscence continues from 07 am to 05 pm. Each anther produces an average of 1609 pollen grains. Floral nectaries located at lower part of ovary, produces an average of 1.80 µl nectar per floret. As a reward, onion flowers produce surplus quantity of pollen and nectar. All the four honeybee species acts as major pollinators in onion ecosystem. Maximum pollinator activity was observed at temperature 28˚c to 32˚c. So thorough understanding of flower morphology, floral biology and phenology helps to have perspective about onion ecosystem services. In this paper, an attempt has been made in this point of view.