best practice management guide for south-eastern Australia - Grains ...

Bees and pollination
13. Bees and pollination
Take care when applying insecticides on crops with nearby beehives.
Trent Potter, SARDI and Don McCaffery,
NSW DPI
All canola varieties grown in Australia are of the Brassica
napus type and, as such, are self-pollinated and generally
do not need pollinating agents such as bees. While the crop
is very attractive to bees, their presence is unlikely to have
any direct effect on yield. Research on the benefits of honey
bees to canola yield is inconclusive. Wind and feral bees
usually make the use of honey bees unnecessary. However,
canola is one of the earliest flowering crops in south-eastern
Australia in spring and so is quite important to commercial
beekeepers. Seed companies use honey bees to produce
valuable hybrid seed.
Photo: F. McRae, NSW DPI
Insecticides and bees
Honey bees find canola very attractive and will travel several
kilometres to forage on the flowers of a canola crop. It is
often necessary to apply an insecticide to control pests
during flowering when the bees are most active. Insecticides
can kill bees and special precautions are necessary to avoid
serious bee losses. Bees are generally inactive in cold,
overcast weather
Insecticides can be less damaging to bees if the correct
chemical is chosen and applied correctly. Some insecticides
have a fairly short residual toxicity to bees (10 hours or less)
and can be safely applied at sunset after most of the bees
have returned to the hive for the day, ensuring it will be safe
for them to return to the crop the following morning.
Some other insecticides remain toxic to bees for several
days after application and are never safe to apply to a
flowering crop. If one of these chemicals must be used,
Canola best practice management guide
75