Rural Industries Research & Development Corporation

Research Compendium 1993 - 1994

Research Project

THE EFFECT OF FARMING PRACTICES ON HONEYBEE FORAGING BEHAVIOUR AND CROP YIELDS

Objectives

• To characterise bee pollination of entomophilous crops (eg cucurbits).
• To determine the influence of registered pesticides on honeybee foraging behaviour in these crops and consequent effects in pollination efficiency, yield and quality of produce.

Background

Many fruit and vegetables require insects for pollination and with declining populations of natural pollinators honeybees have been widely used. Clearly, profitability depends on optimum pollination, which in turn is strongly influenced by crop management practices.

Hence, it is essential in formulating management strategies, to take account of bee biology, crop biology and bee/crop interactions. the use of pesticides is obviously a direct threat to pollinators but it is also suspected of having detrimental effects on other pollination parameters. Better information is required to remain internationally competitive in the production and marketing of horticultural crops.

Research

Studies on a range of cucumber crops were done to investigate:

• the effect of agricultural chemicals (insecticides, fungicides, acaricides and various combinations of sprays) on pollination and crop performance;
• the contribution of bees to pollination;
• the floral and fruit biology of cucumbers; and
• the effect of delaying pollination and fruit development by removing pistillate flowers for varying periods after floral initiation.

Outcome

The significance of bees to pollination was clearly demonstrated where the presence of bees increased fruit set and doubled the number and weight of fruit harvested by comparison to caged controls. Significantly, agricultural chemicals had no effect on the foraging behaviour of honeybees although pollen viability was significantly reduced. This reduced viability was of minor importance as it had no measurable effect in terms of effective fertilisation, and hence yield.

Implications

Some $600 million worth of Australian crop production depends on insect pollination. This study has confirmed the vital contribution of bees in ensuring effective pollination and resultant high yields of quality produce. The effect of agricultural chemicals on bees and pollination reported in this study need to be fully considered in developing effective crop management strategies.

RIRDC Project No: QAC-6A

RESEARCHER: Assoc Prof A H Wearing

ORGANISATION: Horticulture Section

PHONE: 074 60 1230

Last updated: 10 October 1996
Copyright © RIRDC
Index of RIRDC Projects URL
http://www.rirdc.gov.au/pub/compendium/93-94/index-b.html