Effects of pollination by different bees on peach fruit development and quality under greenhouse conditions

Honeybee Apis mellifera and bumblebee Bombus hypocrita are the two main pollinators of greenhouse peaches in China. The effects of pollination by the two bee species on peach fruit development and quality were studied in greenhouse conditions in Pinggu of Beijing City for 2008~2010. The results showed that the diameter growth rate of peach fruit pollinated by B. hypocrita was significantly higher (P<0.05) than that of peach fruit pollinated by A. mellifera. The developmental duration of peach fruit pollinated by the two bee species differed, with B. hypocrita pollinating fruits ripening on the average by seven days earlier than A. mellifera pollinating fruits. While a di-peak physiological fruit-drop was noted in B. hypocrita pollinating fruits, a tri-peak physiological fruit-drop was observed in A. mellifera pollinating fruits. The rate of fruit setting of B. hypocrita pollinating peaches under greenhouse conditions did not significantly changed with the distance of peach trees to beehives. The rate of fruit setting of A. mellifera pollinating peaches under greenhouse significantly declined with increasing distance to beehives. There existed no significant difference (P>0.05) in fruit quality between fruits pollinated by different pollinator species. However, the quality of fruits pollinated by bees was significantly better (P<0.05) than that of the control (artificial pollination). Compared with A. mellifera pollination, B. hypocrita pollination resulted in higher single fruit weight and lower rate of malformed fruit (P<0.05) of peach fruits. In conclusion, the Chinese native bumblebee B. hypocrita was a better pollinator of greenhouses peach than the honeybee A. mellifera.