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Date: | Mon, 27 May 1996 11:04:07 -0700 |
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In Canada
- honey bees work alfalfa (in bloom) for nectar (producing a mild white
honey)
- few of these visits result in pollination (I've heard 1 in 100)
- for alfalfa seed production, bees other than honey bees are necessary.
Alfalfa leafcutter bees are used whenever alfalfa seed is being
produced. The difference in seed yield with leafcutters is 3 to 10 fold.
I've seen remarkable aerial photos of alfalfa seed fields, where petal
fall on pollinated alfalfa shows up clearly. The difference in petal
fall relative to the leafcutter nesting shelters is unmistakable. If
flying conditions are marginal, pollination is good only around the
shelters. With very good flying weather, the whole field is more evenly
pollinated. The NE B.C. and NW Alberta Peace River region has no
chalkbrood in the leafcutter population.
I've talked to alfalfa seed producers in SW US who prefer to use honey
bees for pollination, because honey bee colonies will recover after an
insecticide hit, while leafcutters are affected over a longer period.
The growing conditions, temperature etc are also different, and perhaps
then, more than 1 % of honey bee visits results in pollination.
Insecticides are not often used in alfalfa seed production in the
northern region.
Kerry Clark, Apiculture Specialist
B.C. Ministry of Agriculture
1201 103 Ave
Dawson Creek B.C.
V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299
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