Using Bombus impatiens Cr. as a pollinator of greenhouse sweet peppers (Capsicum annuum L.)

The pollination of greenhouse sweet pepper (Capsicum annuum L. var. grossum cv. Superset) by Bombus impatiens Cr. was investigated in Ste. Scholastique, Quebec for two periods, 27 June-15 July and 4-18 August, 1995 to determine the pollination effectiveness of B. impatiens compared to a mechanical method (vibration wand) and natural greenhouse ventilation (NGV) and to determine the foraging activity of B. impatiens throughout the pollination period. B. impatiens pollination resulted in a significantly greater number of seeds per fruit and a greater percent marketable fruit, due to a positive quadratic relationship between seed number and fruit weight, than both vibration wand and NGV. Both B. impatiens and NGV resulted in a significantly greater fruit set than vibration wand. Per fruit, an extra profit of $0.06 for green and $0.13 for red sweet peppers could be made by B. impatiens pollination over NGV, due to greater marketable fruit and greater mean fruit weight. B. impatiens pollination was more effective than both vibration wand and NGV even though both the daily activity of the insect at the hive (hive traffic) and their foraging on plants (greenhouse foraging) decreased throughout the pollination period and attained a maximum of only 3 B. impatiens foraging in the greenhouse during the second period. It was estimated that a B. impatiens colony of 30-40 workers could optimally pollinate 17475 plants or a greenhouse size of about 9470 m$ sp2.