NEIGHBORHOOD GARDEN FOR DECEMBER 26,
2015
Fruit and Vegetable Crop
Pollination
BY MARION ELLIS,
RETIRED
Extension
Apiculturist (BEEKEEPER),
University of Nebraska-LINCOLN
Cross pollination, or the transfer of pollen from flower to flower, is
an essential step in the production of many fruit and vegetable crops.
Insect-pollinated crops produce small amounts of sticky pollen and rely
on pollinating insects to transfer pollen from flower to flower.
Inadequate pollination can result in deformed fruit or no fruit to
harvest.
Honey
bees are the most important fruit and vegetable crop pollinators.
However, populations of honey bees have diminished during the past
decade due to the Varroa mite, a recently introduced parasite which has
become a major pest in the region. The Varroa mite has caused extensive
losses in managed colonies, and it has increased the labor and expenses
required to maintain colonies. Of perhaps greater significance, the mite
has killed most of the wild (feral) colonies which formerly existed in
tree holes, hollow walls of buildings, and other protected cavities.
This means that fewer honey bees are available in towns, cities and the
surrounding countryside where homeowners have previously benefited from
their pollinating activity.
Fruit and
vegetable growers can encourage native pollinators to help cover the
current “pollination gap.” Providing backyard habitat for native
pollinators such as bumblebees, leafcutter bees, and mason bees may
become a necessary part of both urban and country gardening and fruit
production. Alternately, honey bees can be kept to provide both
pollination and a crop of honey. While Varroa mites have decimated wild
populations of honey bees, skillful beekeepers can protect and care for
honey bee colonies without suffering losses.
Commercial growers should act quickly to ensure fruit set if pollinator
activity is inadequate. Studies show that six bee visits per
blossom are required to obtain a uniform set of well-formed fruit for
most apple varieties.
Fruit and
vegetable growers who have enjoyed the benefit of wild honey bee
pollinators may find it necessary to manage pollinators to obtain good
fruit yields in the future. Bee pollination is as essential as
fertilizing, watering, pest control and other management practices. The
following are things that growers can do to encourage pollinators:
1. Plant forage plants such as sweet clover, Dutch clover, purple
vetch, sunflowers, pussy willow, alfalfa or goldenrod to attract and
sustain pollinators, and let them bloom so the bees can feed on the
flowers.
2. Plant shrub roses, raspberries and other brambles with hollow
or pithy stems to provide nesting sites for solitary leafcutter and
mason bees.
3. Make an artificial leafcutter or mason bee habitat. Untreated
4" x 6" lumber works great. A 1/4” or 5/16" diameter hole can be drilled
in smooth wood on 3/4 inch centers, 2.5 to 8" deep depending upon the
size lumber used. A hole smaller than 1/4” or larger than 5/16” will
attract undesirable bees and insects. A 5/16" diameter hole is important
for attracting Mason Orchard Bees. Do not drill completely through the
lumber. Attach a roof to provide protection from the midday sun and
rain. Outside surfaces may be painted or stained, but do not use wood
preservatives.
Copyright 2015
For more information
go to:
http://www.ars.usda.gov/Main/docs.htm?docid=10743
((Build a Nest Board, Agriculture Research Service, USDA)
http://king.wsu.edu/foodandfarms/documents/MasonBee.pdf
(Orchard Mason Bees, Washington State University Extension Service in
King County)
http://gage.unl.edu/artificialhabitatfortubenestingbees
(How To Build Artificial Habitat For Tube Nesting Bees, UNL Extension in
Gage County, NE)
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