First report of wind pollination in pigeonpea

Abstract

The c1eistogamous flowers of pigeonpea (Cajanus cajan (L.) Millsp.) predominantly favour self-pollination but, unlike other legumes, it is not a rule and a considerable extent of natural cross-pollination has been reported [1]. Howard. et al. [2] were the first to report 14% natural out-crossing in pigeonpea at Pusa Agricultural Research Institute in Bihar. It was followed by a number of similar reports with up to 70% natural out-crossing. A variety of insects are attracted towards the large bright coloured pigeonpea flowers and the natural out-crossing has been reported to take place as a result of their frequent visitation from one flower to another within and across the fields. The known major pollinating vectors are Megachile lanita, Apis flarea and Apis mellifera [3, 4]. Onim [5] reported that each insect visit lasts betweeen 15-55 seconds and they trip the unopen floral buds and thereby introduce foreign pollen on the stigmatic surface to affect the cross-fertilization. Williams [6] counted between 5500 and 107333 pollen grains on the body of a single pollinating insect of which pigeonpea pollen accounted for 98-100%.