Pollination in Cages

Abstract

This chapter describes the need for pollination in greenhouses due to its special agro-ecological conditions and unique constraints. The advantages that greenhouses hold for both achieving pollination of particular crops and for safeguarding managed pollinators are compared with open air cultures. The traits of the two main greenhouse pollinators – bumble bees and honey bees – are discussed according to their relevance for pollination in this horticultural system. Finally, some examples of pollination of greenhouse cultures and predictions for the future development of pollination in greenhouses are described. The need for insect pollination of plants in enclosures arises either because the plants must be isolated to produce uncontaminated seed, or because attempts are being made to find whether the species gives increased seed or fruit following insect visits, or because the crop is being produced under artificial heat in a greenhouse. Whichever of these reasons applies similar problems is encountered. During the early stages of plant breeding hand-pollination can produce sufficient seeds but with expanded programmes of breeding and testing this becomes too laborious and time consuming, and bumblebees, honeybees, blowflies, and more recently, solitary bees have been used to pollinate the flowers.