By Sharon Omahen
University of Georgia
Researchers at the University of Georgia are using the same electrostatic charges that make your socks stick to your sweaters to help bees pollinate plants.
"Parasites, habitat destruction and pesticides are reducing the population of honeybees," said Hazel Wetzstein, a horticulturist with the UGA College of Agricultural and Environmental Sciences. "We aren't trying to replace bees. We're just trying to help them."
Crops need pollination
Growers of many fruit, vegetable and nut crops rely on proper pollination.
"Any crop where the fruit or the seed is the final result needs to have adequate pollination and fertilization for there to be good fruit development," Wetzstein said. "Pollination impacts the yield and the quality of many crops."
When you see lopsided apples, that's likely the result of poor pollination and fertilization. "And watermelons and squash will be smaller and distorted when they're poorly pollinated," she said.
Offering bees some help
To offer the bees some help, Wetzstein and Ed Law are using forces of electrostatic charges to apply pollen to plants. Law is a biological and agricultural engineer with the UGA Applied Electrostatics Laboratory in Athens, Ga.
"Lint attached to synthetic fabrics in a clothes dryer is one example of electric force fields. But we usually consider this a nuisance," Law said. "Instead, we're beneficially using electrostatics in the same way it's used to apply paint to cars and appliances."
Some Vidalia onion growers and greenhouse operators in Georgia, cotton farmers in the Southwest and vegetable growers in Central America routinely use electrostatic crop sprayers developed at UGA, he said.
"Electrostatic forces greatly improve the deposition of sprays onto leaf surfaces so farmers are able to reduce the amount of pesticides they dispense from spray nozzles and still get the required amount on their crops," he said.
"This leads to a tremendous savings to the farmer in crop production costs," he said. "Both the environment and the million or more acres of crops annually sprayed electrostatically also benefit from the improved application method."
Spraying extra pollen
The same technology is being used to spray extra pollen, liquid or powder form, onto crops.
"We sprayed charged pollen onto crops and found the pollen penetrates better," Wetzstein said. "In a crop like almonds, where fruit set may be only 30 percent, we can potentially increase the set and the yield dramatically."
There are down sides, though. "Pollen is pretty difficult to collect and expensive to buy," Wetzstein said.
Besides the electrostatic method, Law and Wetzstein are studying other ways to enhance pollination.
Better ways to pollinate
"Plant breeders and hybrid seed producers use specific types of pollen to make their crosses," Wetzstein said. "Much of the pollen applied to flowers is wasted or lost because it's difficult to apply small volumes uniformly. We are researching ways to dilute the pollen to extend its use and decrease the amount required."
When humans do the work of bees, it's tedious and time-consuming.
"To have pollen for crosses, workers at seed companies must harvest flowers, separate and clean the pollen and maintain its viability during handling and storage," Wetzstein said. "This is problematic with many floral and vegetable crops which have extremely small flowers and little pollen. Finding ways to extend pollen use would bring production costs down."
The scientists have also found that spraying fungicides and pesticides affects pollination.
"In the springtime, growers have to spray when the flowers are blooming," Wetzstein said. "We've found that some of the common fungicides can damage the flower stigma and have a toxic effect on the pollen itself."
But farmers can't stop spraying to control pests and diseases.
Wetzstein and Law are now working to find out how much damage specific pesticides and fungicides cause and to develop recommendations for farmers.
"In parts of China, field workers apply pollen in apple orchards by going from tree to tree with a paint brush," Wetzstein said. "Our goal is to find mechanized ways of applying pollen and to find ways to help the bees be more effective."
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)