Vinod Prasad Khanduri

pp. 389 - 396

Abstract

Flowering phenology and variation in total pollen production per tree in the natural population of Lagerstroemia
speciosa was studied during four successive years, from 2006 to 2009. Reproductive phenophases were highly variable
between years and individuals within population. Total flowering period lasts up to three months. Time of maximum anthesis
was between 06:00 and 10:00 h of the day. On an average a flower took 2.5 to 3.0 hours for complete opening. Anther dehiscence
occurred half an hour after anthesis. Apis spp. and Xylocopa spp. were observed the main pollinators. The visitation rates of
pollinators varied from 0.62 to 2.82 visits/flower/hour with the average of 1.68±0.94 visits/flower/hour. Xylocopa bee shows
physical fitness with flower morphology, which implies the functional relationship with regard to pollen transfer. There was
alternate year production of flowers and pollen grains per tree. In the mass production years, a tree produces 6.4 x 10⁸
 and
1.3 x 10⁹
 pollen grains, which in poor production years oscillated between 4.2 x 10⁷
 and 5.4 x 107
. 64% to 80% fruit set following open pollination in mass production year was estimated.