A. Dag et D. Eisikowitch, Ventilation of greenhouses increases honey bee foraging activity on melon,Cucumis melo, J APICULT R, 38(3-4), 1999, pp. 169-175
Melons are grown in Israel in 'walk-through' tunnel greenhouses. We compare
d honey bee (Apis mellifera) foraging activity and melon nectar characteris
tics in well-ventilated and in closed greenhouses. Foraging activity in the
open greenhouses was two- to five-fold greater than that in the closed gre
enhouses. This higher activity could be explained by higher flower attracti
vity due to a higher nectar sugar concentration both in hermaphroditic flow
ers and male flowers. The higher sugar concentration in the open, ventilate
d greenhouses was probably as a result of the relatively lower humidity the
re. The greater foraging activity in the open greenhouses also may have bee
n due to lower air temperatures and better accessibility for the bees. It s
eems that greenhouse ventilation can improve honey bee pollination activity
in melon and probably other greenhouse crops as well.