Vol. 11, Special Issue 11 (2022)

The Pongamia pinnata is being an important biofuel plant which is distributed in the tropical and subtropical areas of the world, pod yield of this plant is very much negligible due to scarcity of information on the floral biology and the flower visitors of P. pinnata. The present study was undertaken at the UAS, GKVK, Bengaluru to document its floral biology and the flower visitors in the South Eastern Dry Zone of Karnataka. Flower structure, anthesis, anther dehiscence and pollen to ovule ratio, pollen germination, stigma receptivity and flower visitors were documented and studied in detail. The results revealed that the flowering (acropetal) period was observed between first fortnight of march to first week of May month with a peak period of 20-25 days. It has a unique floral architecture with bisexual, zygomorphic and have one large standard petal, with two light-purple wing petals and two white keel petals. Anthers and stigma are enclosed but separated in the boat-shaped keel petals. Anthesis was observed at 0830 h and reached peak at 0900 h and started decreased at 1000 h. Anther dehiscence was noticed 1 or 2 hours prior to anthesis. Pollen to ovule ratio was 15125±1375.63: 1. The Pollen germination was 92.28 to 94.21% and stigma receptivity was 77.03 to 85.82% was maximum between 1000 to 1200 h. During the study the major flower visitors were Megachilid and Honey bees followed by Thrips and Syrphids.