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) parent s of sunflower(Helianthus annuus L.). Observations revealed that all the 5 species of honeybees, viz Apis dorsata, Apis mellifera, Apis cerana, Apis f lorea and Trigona irridipennis participated In foraging in sunflower throug hout the day. Two peak foraging periods were encountered in all the species . The filled seed weight, grain filling (%) and oil-content were considerab ly increased in the plots pollinated only by the honeybees. The seed weight was maximum (25.04 g/head) in honeybee pollinated plot followed by hand an d 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 fem ale parent. However, it was recorded lowest (5.16 g/head) in check plots wi thout hand or bees pollination. The grain filling (%) (92.95) and oil conte nt (%) (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 pl ots pollinated by bees and other pollinators followed by exclusively hand p ollinated (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 othe r insects pollinated plot followed by exclusively hand pollinated (395.31) and check plots (238.70).