Red clover is almost completely self-sterile, and consequently a main factor in seed production is the efficacy of the cross-pollinating agencies. Cross pollination in red clover is mainly effected by species of bumble bees and by honey bees. In older cultivated areas the population of wild bees is on the decrease and this has led to corresponding decreases in red clover seed production. The honey bee does not work red clover as diligently as the bumble bee. This is believed by many observers to be due to the nectar being more difficult to obtain by the honey bee, because of its shorter proboscis. This has stimulated an attempt on the part of plant breeders to develop strains of red clover with shorter corolla tubes which would be readily worked by the honey bee. Two such strains developed by plant breeders in Bohemia were recently secured by C.B. Gooderham, Dominion Apiarist, and are under test by the Division of Forage Plants, Experimental Farms Service, Ottawa. In this paper the results of an experiment are recorded in which the relative seed production of these new strains in comparison with a standard red clover variety was studied under controlled conditions.
Armstrong, J. M., "Cross-Pollination of Red Clover by Honey Bees" (1940). An. Paper 107.
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