Bees and broadacre crops
02 Aug 2022
By Tim Bartimote, Cropping Adviser
As beekeepers across NSW respond to the Varroa Mite outbreak, many farmers are wondering what impact the restriction on bee movements this will have on broadacre crops across our region.
Bees have long been considered beneficial to broadacre crops. But exactly how helpful are they?
Pollination methods vary across different broadacre crops. Cereals like wheat, oats and barley are known as self-pollinators. Therefore, insects are typically of little benefit in improving pollination. Other crops cross pollinate and require pollen from another plant to achieve fertilisation. Some crop species, like maize, achieve this largely through wind pollination. However, many others benefit from insect pollination.
Several scientific studies have shown that a range of crops benefited in yield and quality when beehives were located nearby. In the year 2000, an experiment evaluating the impact of bees on canola suggested a potential yield benefit of up to 16%1. While another study in 2005 found a 20% yield difference when beehives were located less than 200m away from the canola crop. The beehive density being 1 hive/ha.2
While the benefits of bees in canola are widely known, it is important to remember that other crops can also profit significantly from insect pollination. Sorghum, faba beans, field peas, lupins, and even pasture species like white clover have been found to benefit from bees.3 For example, in faba beans a hive density of 2 hives/ha is suggested to achieve yield benefits. It is also important to minimise travelling distance for the bees, with an ideal distance of less than 500m to reach the targeted crop .4
Native bees are also important pollinators. Recently, work has been conducted to expand this emerging industry. Stingless bees have been identified as valuable pollinators and are being used extensively in the horticulture industry. With research being conducted regarding application to other crops. Currently, native bee companies are still able to travel and provide services.
As crops begin to flower and the varroa mite situation unfolds, it is important that producers bee mindful of the value of these insects. This may include making use of them in other broadacre crops when applicable, as well as considering ways to minimize harm to bees. By knowing the proximity to nearby hives when spraying insecticides, as well as utilising softer insecticide options where possible will assist in protecting both our native and honeybee populations.
References
- Manning R. and Boland J. (2000) A preliminary investigation into honey bee (Apis mellifera) pollination of canola (Brassica napus cv. Karoo) in Western Australia, AJEA 40,439-442.
- Manning R. and Wallis IR. (2005) Seed yields in canola (Brassica napus cv. Karoo) depend on the distance of plants from honeybee apiaries, AJEA 45, 1307-1313.
- Goodman RD. and Williams AE. (1994) Honeybee pollination of white clover (Trifolium repens L.) cv. Haifa, AJEA34, 1121-1123.
- Somerville D. (2002) Honeybees in faba bean pollination, NSW Agriculture agnote.
- Goodwin M. (2012) Pollination of Crops in Australia and New Zealand, The Pollination Program.