Potentiality of honeybees in hybrid seed production of sunflower (Helianthus annuus)

A field experiment was conducted during summer 1995 on honeybee pollination at Bangalore using cMS 234A and 234B(female parent and maintainer) parents of sunflower (Helianthus annuus L.). Observations revealed that all the 5 species of honeybees, viz Apis dorsala, Apis mellifera, Apis cerana, Apis florea and Trigona irridipennis participated in foraging in sunflower throughout the day. Two peak foraging periods were encountered in all the species. The filled seed weight, grain filling (%) and oil content were considerably increased in the plots pollinated oJ1ly by the honeybees. The seed weight was maximum (25.04 g/head) in honeybee pollinated plot followed by hand and bees pollinated (24.78 g/head); pollination by other pollinators (13.59 g/head) and exclusively hand pollinated (12.98 g/head) plots in case of female parent. However,it was recorded lowest (5.16 g/head) in check plots without hand or bees pollination. The grain mling (%) (92.95) and oil content (%) (53.10) were also maximum in the plots pollinated with bees. In case of maintainer (234B),the seed weight was maximum (14.49 g/head) in the plots pollinated by bees and other pollinators followed by exclusively hand pollinated (12.66 g/head) and check plot without hand or bees pollination (9.75 g/head). The number of seeds was also maximum (407.95) in bees and other insects pollinated plot followed by exclusively hand pollinated (395.31) and check plots (238.70).