Measures to increase the pollination of lucerne (Medicago saliva Linn.)

Abstract

The effect of excluding pollen sources other than lucerne from honey bees was studied by enclosing areas of a lucerne seed crop with cages containing hives, and comparing pollination in these with that in the surrounding crop. Greatly increased pollination was obtained from ‘Wairau’ lucerne grown under such conditions and worked solely by typical commercial strains of bee. The elimination of competing pollen sources is uneconomic. Hence the effect of moving successive waves of hives, with a maximum population of young bees, to lucerne crops to promote tripping, and so increase lucerne seed yields, was studied. This measure proved of no practical value under New Zealand conditions. A hive concentration of iess than one per acre cannot be guaranteed to give adequate pollination under all conditions.An investigation of honey bee visitation to the flowers of lucerne crops showed bee coverage was apparently sufficient to give adequate seed set if bees could be induced to gather pollen rather than collect nectar. Improvement in lucerne pollination appears possible only by the introduction of new species of pollinators. © 1972 Taylor & Francis Group, LLC.