Released October 19, 2012
PINE BLUFF, Ark. – As growers begin to plan for the next crop year, they should consider pollinators and include them in their agricultural planning, says Dr. Yong Park, assistant professor and entomologist at the University of Arkansas at Pine Bluff.
Of the100 crop species that supply 90 percent of the world’s food, bees pollinate more than 70 percent, says Dr. Park. The world’s growing population means that more bees will be needed to pollinate crops to feed more people. Some experts estimate that pollinators can increase yields up to 35 percent.
Without pollinators, yields are greatly reduced and diets would be less colorful. If an apple is poorly pollinated, it becomes small and lopsided, says Dr. Park. An unpollinated flower won’t develop into an apple at all.
Fifty to 60 years ago insects were the best agricultural pollinators. Farmers took natural pollination for granted. Ironically, as increasing amounts of forest land, where many pollinators prefer to live, was turned into farmland, farmers turned to renting managed hives to pollinate their crops.
Insects, including honey bees, are not the only pollinators. Birds, bats and the wind deserve some credit along with native bees, such as bumble bees, sweat bees and carpenter bees. Honeybees cannot pollinate sweet corn, rice, tomatoes, blueberries and flowers having long-tubed flowers.
“Native bees, such as sweat bees, leafcutter bees, mason bees, carpenter bees and other insects must do the job,” says Dr. Park. There are some 3,000 different species of native bees in the United States, he says. Native bees are specialists whereas honeybees are generalists.Native bees are essential for pollination of specific plants.
Native bees are not available year-round, and they do not travel far from their habitat, says Dr. Park. Depending upon the species, their range is typically 200 feet to less than 1,000 feet. Native bees live and lay eggs in the soil, on twigs and in hardwood trees.
Pesticide usage, disturbance and loss of habitat, and insect-resistant genetically modified crops are the biggest threats to pollinators. “Because pollinators visit plants one week before, during and one week after blooming, growers should plan pesticide applications to do the least harm to honeybees and native pollinators,” says Dr. Park.
Carefully monitoring fields for early detection of pests can help determine the best timing for pesticide application with the least harm to pollinators. Protecting, enhancing and restoring wildflower-rich foraging habitat along with the careful timing of pesticide application are the most significant steps growers can take to protect pollinators.
Growers should include in their agriculture landscape a pesticide-free area of diverse plants to provide pollen and nectar for pollinators throughout the local growing season. “Ideally, plan a separate plot for each plant species,” says Dr. Park. The plot can be either a square or a circular one, but it should have a diameter of no less than three feet.
Locate these plots within 500 feet of the designated farm field as Dr. Park reminds growers that native bees do not fly long distances. Plots should contain mixed flowering plants so they will flower throughout the year.
Also, when tilling, growers should leave an area near plants/crops needing pollination, untilled. Chances are that native bees or their progeny in various stages of development are hibernating in the soil.
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University of Arkansas, http://www.uaex.edu/news/october2012/1019UAPB.html#.ULTUDIbfKuI