||Partners in Production: How to work with
pollinators to improve your harvest
If you've seen abundant honey bees on your farm lately, count yourself
among the lucky. Beleaguered by mites, disease, pesticides, bad weather,
and the invasion of Africanized honey bees, the crop-loving European honey
bee has been the subject of dire predictions of doom and loud proclamations
in its defense. USDA numbers indicate that we've lost over half the wild
and domestic colonies that we had on farms and ranches in 1950, and half
of that loss has occurred since 1990. Whether or not the honey bee is indeed
on a collision course with destiny, the discussion has brought an often
overlooked aspect of food production into focus - pollination.
"A modern farmer can't assume that pollination of his fruit and vegetables
will just happen," say South Carolina beekeepers, Dave and Janice Green.
"The pollination scene is a rapidly changing story, and pollination has
to be managed, just like fertility, or pest and disease control."
Pollination is crucial for the production of viable seeds and for fully
developed, tasty fruit. From the experience of many of us who grew up on
farms, this critical process just happens naturally, without any high-tech
intervention. For grains and some nut crops, the wind ensures seed set;
but for most fruits and vegetables, insects come into play. Largescale
fruit and nut growers like California's almond producers, who think a lot
about pollination, usually depend on beekeepers to provide adequate numbers
of domestic honey bees when the crops are in bloom. However, honey bee
populations have recently declined, and commercial pollination fees have
increased in parts of the country. If you grow on a smaller scale, you
may find renting or keeping bees expensive. Some growers report only recently
noticing spottiness in their orchards and misshapen fruit, indicating pollination
"All of our local wild bees are gone," reports H.K. Johnson a beekeeper
in Harnett County, North Carolina. "Our watermelons produce only three
to five fruits in a whole field - the future looks grim."
The decline of honey bees, however, does not mean crop failure. "We
have not had problems with pollination on our small farm because we raise
several kinds of bees and encourage pollen and nectar-producing plants
throughout the year," says Raymond Williams of Beetberry Farm, New York.
"There is, however, a critical shortage of pollination in the Northeast,
as almost all, if not all, of the feral honey bee colonies have now been
destroyed by mites. Many produce farmers in the Northeast are noticing
decreases in production."
Whether you rent hives now or have never given two cents for a pollinator,
determining what kinds of bees pollinate your crops and what you can do
to work with them, will go a long way towards improving the size, quality,
and dependability of your harvests. Even if you aren't experiencing yield
declines, better pollination can provide you with better looking and tastier
harvests. The time is ripe.
What is pollinating your crops?
One reason many growers are not experiencing declines in yields, even
as the wild honey bee is disappearing, is the presence of many other wild
bees who are not vulnerable to the same diseases and pests. The Forgotten
Pollinators Campaign sponsored field research this summer on pumpkin and
squash fields in Maine, Alabama, and Arizona to find out how pollinating
was being done. In all three states, the researchers found that in fields
that may have once been primarily pollinated by feral (gone wild) honey
bees, the lion's share of the pollination job is being done by native bumble
bees, squash and gourd bees and their wild kin.
Are your crops under-pollinated?
"Symptoms of inadequate pollination (as opposed to nutrient deficiencies
or disease) are often unrecognized," says Dave Green. "The poor quality
is often blamed on weather or other factors. It surprises me how many growers
don't know the simple and basic tool of counting seeds for apple pollination
evaluation, for example" he says. "We may perpetuate false ideas by referring
to apples as being "set," when we really should talk about seeds being
set. It requires multiple visits by a bee to each blossom to make the apples
that make the money."
To find out how well an apple was pollinated, simply slice the fruit
crosswise and check for two seeds in each of the five seed pockets. Count
only fully developed, not withered, seeds. The bagged supermarket apples
usually have only two or three seeds, while large gourmet apples may have
six or eight. Green suggests that growers keep yearly records on how well
varieties are pollinated along with any information like how many honey
bee colonies were rented, where they were placed, or what other native
bees may have done some or all of the pollinating in your fields.
What you can do to create a pollinator-friendly environment:
Lack of suitable pollen and nectar plants present a fundamental problem
to the wild bees you may rely on for pollination. All too efficient herbicides,
and the removal of fence-rows, wild strips, and fallow lands all reduce
forage and nesting sites for wild bees. Sweet clover is eliminated from
fields by herbicides, for example, but is also replaced by herbicide-tolerant
plants like Dalmatian toadflax, yarrow, and deadly nightshade, that offer
almost nothing for bees.
If you have any arable land or wood lot acreage you can sow to green
manures or cover crops, you can encourage native plants that offer food
and shelter to wild bees. Clovers, alfalfa and other legumes, sunflowers,
thistles honeysuckles, sweet milkweeds, sages, salvias, beebalm and other
mints (bees love mints) are just a few of the many plants that provide
wild bees with nectar and pollen.
How to spray if you have to -- or how to talk to neighbors who spray
On his 18-acre fruit and vegetable farm in New York, Raymond Williams grows
mixed nectar plants for bee pasture to support wild bees and the bees he
raises, which include honey bees, orchard bees, hornfaced bees, blueberry
bees, and alfalfa leafcutter bees. "We grow about six acres of nectar plants
including red alsike, dutch white, and sweet clovers, birdsfoot trefoil
and alfalfa. Also annually, we plant buckwheat for bloom at varying times.
In the fall, golden rod and New England asters are everywhere."
Goldenrod provides especially important food for bees, since it is one
of the last heavy-yielding plants of the season and the pollen is high
quality for bees. Unfortunately, goldenrod is often falsely blamed for
allergies caused by ragweed and so is often kept mowed.
Many of the practices that will encourage wild pollinators in your fields,
will also encourage other beneficial insects. Richard de Wilde in western
Wisconsin shelters beneficials in his vegetable fields with 8 foot wide
hedgerows. He plants an understory of grass mixes like creeping fescue
and ryegrass with a row of shrubs and a row of flowers. Grasses can supply
pollinators with shelter and resting places. Depending on shrub selection
the hedgerows cost 38 to 88 cents a foot. He looks for flowers and shrubs
that bloom throughout the year in order to provide a continuous source
of nectar and pollen. He also plants ones that have a good shelf life because
he markets them with the vegetables. He plants black-eyed Susan, purple
coneflower, daisies, dogwoods, and curly willow.
Not everyone farms organically. But as many beekeepers are well aware,
the risks of pesticides extend far beyond the boundary of a field. Growers,
homeowners, and even state-run insect and weed control programs may not
be fully aware of the implications of their spraying practices. Here are
a few guidelines for minimizing the negative effects of pesticides on pollinators.
If You Rent Pollination Services:
Don't spray when pollinators are at work. Whether you use honey bees or
rely on wild bees it is essential that you monitor for foraging bees as
pesticide labels require. "I am firmly convinced that pesticide misuse
is a bigger problem than Varroa mites," says beekeeper Dave Green. "It
certainly has cost me a lot more dead and weak hives." David Pimental of
Cornell University has done research indicating that one in every five
honey bee colonies that has died in recent years was made critically vulnerable
by exposure to pesticides - an exposure that growers can avert at very
Also, many states refuse to recognize that pesticide label directions
do refer to wild bees as well as managed ones. Conformity with the label
directions is required by law and is the responsibility of the pesticide
applicator, but many applicators will assume that wild bees are simply
not present, ignoring, for example, a weed bloom such as wild mustard in
grain fields or clover in orchards, that will draw bees into the application
area and lead to bee kills. Flowers outside the spray area, where drift
may reach the flowers (clover blooming next to sweet corn, for example)
also poses risks to pollinating insects.
In New York and Michigan, poison applications on blooming (tasseled)
sweet corn can cause damage, because bees visit the tassels. The poisoning
becomes much more severe when goldenrod is blooming in the fields or hedgerows,
and aerial applicators contaminate this pollen, which is MUCH more attractive
to bees than the corn.
Choose pesticides with pollinators in mind. With the newer, non-residual
pesticides that are often used today, bees are protected if the grower
just doesn't apply during foraging time. Once the pesticide is dry, there
is little further threat to bees. Residual pesticides such as Penncap M,
Sevin, or any of the organophosphates should never be used during bloom.
Not only is there a direct effect on bees visiting blooms, but residues
are quite toxic and will be gathered in pollen and nectar and taken back
to the hive to cause death in young bees and brood. Also, while the egg-laying
honey bee queen stays in the hive and so is less exposed to the threats
of a chemical kill, female leafcutting, orchard, and alkali bees all forage
for pollen, and are thus exposed to pesticide residues. In 1980, U.S. economic
losses due to pesticide poisonings of honey bees and reduced pollination
was estimated at $135 million.
Even target-specific pest control agents can affect a wide range of insect
life. Bacillus thuringiensis, or Bt, a bacterial pesticide, has been touted
as an environmentally rational approach.. But studies have shown that when
Bt was sprayed to control gypsy moths in Oregon, numbers of non-target
types of butterflies and caterpillars declined. Some of these insects serve
as biological control agents themselves, or as important food resource
for other wildlife.
Cooler weather means a dramatic increase in the residual killing action
of insecticides. Furadan has a residue hazard of one week in warm 70 degree
weather, to greater than two weeks in 50 degree weather. Spur (fluvalinate),
an insecticide considered non-hazardous to bees, gave a 30% increase in
honey bee kills at cooler temperatures. Unusually cold nights following
hot summer days causes lots of dew to form on leaves, which presents a
bee poisoning problem as more of the chemical residue remains.
Climate affects the hazard of a given pesticide. Malathion, for example,
has a fumigant effect on bees in warm California, but not in cooler Washington.
Phosdrin (mevinphos) has a short residue time in California, but will cause
large bee kills a day later in Washington. In arid eastern Washington,
Lannate (methomyl) is safe for bees if applied late in the evening, but
in the east, less arid areas of the west, and in the Midwest, it is hazardous
for a much longer period of time.
Use a lower-hazard formulation of pesticides when you must apply them.
Dust formulations are usually more hazardous to bees than sprays and granules.
Wettable powders often have a longer residual effect than emulsifiable
concentrates. Microencapsulated insecticides, which extend the life of
the chemical through slow-release through the plastic walls of a capsule,
are extremely hazardous to bees since the capsules are about the same size
as pollen and adhere readily to bees.
Use lower-hazard application methods. Systemic insecticides injected into
the soil are safer than spraying them on plants. Fine sprays are safer
than coarse ones. And ground application is much safer than aerial application,
because the chemical drifts less, and smaller areas are treated at one
Despite the struggles honey beekeepers have faced recently, they remain
capable of moving large populations of pollinators into fields or orchards
at bloom time - critical for largescale agriculture. California is probably
the best example of a state where large-scale growers rely on rented colonies
of honey bees to insure adequate pollination. California growers need to
augment local bee populations for their crops of almonds, plums, prunes,
cherries, apples and other tree fruit crops, melons, and alfalfa. The annual
value of these crops is several billion dollars, and to ensure adequate
pollination California farmers rent about 1.4 million hives a year, about
half for almonds alone. This accounts for half of all bee rentals in the
entire country! California growers maintain such large and intensive operations
that they must rely on contracts with migrating beekeepers from out-of-state.
Moving bees from state to state exposes them to mites, diseases, hybridization
with Africanized bees, and risk of pesticide exposure - all of which are
taking a heavy toll. According to USDA statistics, domestic honey bee colonies
declined from 2.5 million in 1995 to 1.9 million in 1996 -- 20% in just
one year. And this is following a decline of 25% between 1990 and 1995.
California almond farmers have been feeling the results of these problems,
too. In 1995, beekeepers were paid over $40 for each hive used for pollination
rentals on almonds, a doubling of rental fees in ten years. Almonds require
30 to 60 percent fruit set for a successful crop, a task which requires
two honey bee colonies per acre.
Help us provide growers like you with pertinent information on pollinators.
Please take a moment to answer the questions below. Add as much information
as you like and mail it in the stamped envelope to the Forgotten Pollinators
Campaign at The Bee Works 1870 West Prince Rd Suite 16 Tucson, AZ 85705.
What to look for when renting a honey bee hive. According to Dave Green,
a grower should check the hives he is renting for pollination services.
With the keeper's cooperation, a grower can often borrow an extra bee veil
and do a simple check to see how many frames the bees cover in a hive.
This will indicate how well the bees can provide pollination services.
Ideally, says Green, the bees should cover seven to eight deep brood frames,
which represents about five to six frames of brood. A hive with only five
frames covered with bees is not quite up to par, unless most of the bees
are out foraging. A hive with ten frames covered, on the other hand, may
be too strong. Bees that have no space to develop will be apt to swarm.
Swarmy bees have their minds on moving to a new home and are poor workers.
Do you keep bees? If so what kinds (honey bees, Mason bees,
Alfalfa leafcutter bees)?
Do you rent bees? How many and how often?
How large is your orchard/farm and what crops do you grow?
Have you experienced problems with pollination on your farm - such as
areas of lower fruit set in your orchards, or misshapen fruits?
Have you noticed any changes in the abundance of bee pollinators on
your farm in the last 2 - 3 years?
Are you certified organic? Do you, or your neighbors regularly use insecticides
or microbial pest controls like Bt?
Do you, or have you, planted forages to attract/augment pollinators,
or set land aside for pollinators?
What kind of information on pollination would be useful to you?
How do you get your information?
____magazines/journals (please list titles)
____other (please describe)