As the most important pollinator of onions, the honeybee delivers a valuable, cost-free service to onion seed farmers in the Klein Karoo. This is according to Dr Mariëtte Brand, who recently completed a doctoral study in conservation ecology at Stellenbosch University. Her study shows that wild and managed (those in hives) honeybees play a vital role in the production of onion hybrid seeds by carrying pollen from male to female plants.
“There’s a direct link between seed yield, the number of honeybee visits and the cultivation of more male plants,” says Brand.
She adds that honeybee pollination of onion plants is in fact remarkable because the insects generally prefer other nectar sources. The pollination ecosystem services provided by wild honeybees can “reduce the input costs of seed production by lowering the demand for rented hives”. The latter may be temporarily required if there are not enough local honeybees to pollinate onion plants.
“Pollination by bees can protect seed farmers in the Karoo from major losses,” says Brand. In 2012, for example, farmers suffered crop losses when honeybees failed to pollinate onion plants during the blooming season. Her study shows that the number of honeybees in onion lands is generally determined by good and timely rainfall that allows local wildflowers to flourish, in turn providing sufficient nectar and pollen for bee colonies to multiply.
Phone Martin Viljoen, Stellenbosch University on 021 808 4921 or email [email protected].