A new way to protect plants

Tired of deer and rabbits treating your landscape like a salad bar? Soon you'll have a new weapon in your arsenal, courtesy of a Minnesota inventor.

Tom Levar, a scientist at the University of Minnesota Duluth, has developed a new way to protect plants from hungry pests -- by making them taste nasty. But instead of spraying the stuff on foliage, Levar's method delivers a hot pepper concentrate through the roots, for a lasting yuck factor.

As most gardeners know, the products currently on the market do deter pests but they're short-lived and subject to the vagaries of weather. "They're effective as long as they don't wash off or evaporate," said Levar. That's why he developed a formulation that allows root penetration of a bitter-tasting compound at the molecular level.

It's a "game-changing technology," according to Repellex USA, the company that licensed Levar's innovation from the U of M.

Jeff Gillman, associate professor of horticulture at the University of Minnesota, hasn't tried the product, but if it works the way it's billed, he agrees that it'll indeed be a game-changer. "There's mainly topical stuff on the market now," he said. "There's nothing I know of that has that effect."

Levar, a forestry and horticulture specialist at UMD's Natural Resources Research Institute, got the idea while exploring cancer treatments for his wife. He learned how dimethyl sulfoxide (DMSO) was used in veterinary and sports medicine to open pores in a membrane and move medicines through skin. He then modified the compound to make it more plant-friendly and added a bitter substance, the active ingredient in products designed to keep children from sucking their thumbs.

There is no genetic modification, Levar said. Eventually, the plant will outgrow the treatment, but it lasts much longer than spray repellents.

Repellex tested the product with tree growers in nurseries, where mice are a major destructive force. "We think professional growers and homeowners will find value in planting two tablets with their trees and not having to worry about their investment," said Elizabeth Summa, president of Repellex.

The product, Repellex Systemic, has been submitted to the U.S. Environmental Protection Agency for registration. Once approved, it will be shipped to retailers, probably in time for the spring planting season. The product is best applied in May or June, when the soil is at least 50 degrees and plants are actively growing and absorbing water through their roots, Levar said.

He'll be using it on his own landscape. "I have 2 acres in Hermantown, and deer love my shrubbery and hosta," he said.

But he has loftier hopes for the technology he developed. "I would like to see it applied to food production," he said. "It has tremendous potential to help feed people," by increasing nutrition and vitamin content in grains, particularly in Third World countries. "There are lots of applications."

So does that mean Levar stands to make a lot of money? "It might make my grandchildren rich. Not me," he said. "It's owned by the U of M, and all their costs have to be defrayed first. I might be able to buy a good cigar."