Pollination of crops by bees: why and how?
2004
Sihag, R.C.,CCS Haryana Agricultural Univ., Hisar-125 004 (India). Dept. of Zoology and Aquaculture
A large number of crops are unable to utilize their own pollen due to the existence of several breeding barriers. The latter include self-incompatibility, differential maturity of the reproductive organs, unisexuality and heterostyly. Under these situations, pollen must come from another flower. Water, gravity and wind are the abiotic agents which are less effective and reliable pollinators. On the other hand, many animals, especially insects, are very effective pollinators. Among them, bees are the most effective and reliable pollinators due to their dependence on flowers for their brood food. Several social and solitary bees can be utilized for the pollination of crops. Among the social bees, two species of honey bees,namely Apis mellifera and A. cerana, have been domesticated and are being used as very effective and reliable pollinators of crops due to their polylectic habit. Methods for culturing these species, such as when, where, and how to place the colonies and the kinds of colonies to be utilized, have been standardized. Other groups of honey bees, including the stingless bees, can also be domesticated and utilized for the pollination of crops, especially in hot climates. Bumble bees, which are natives of cold climates, and are very interesting as well as reliable pollinators which can be kept in screen- and poly-houses. They can work at low temperatures and are easily manageable. Another sub-social bee, Xylocopa, is a pollinator of several cucurbit crops, and its management practices are now available. Among specialist pollinator of crops, Solitary bees of the family Megachilidae are the most important. They are very reliable pollinators of crops like alfalfa, berseem, pigeon pea and several others, and can easily be domesticated and managed for the pollination of these crops, especially for the production of hybrid seeds in poly houses. Methods of their management and utilization as pollinators of crops are now known.
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