Sun-Based Dust Buster
Sunflower hulls are a key ingredient in a new seed treatment carrier developed for the potato industry.
Paul Kresge, an agronomy consultant from Forest Lake, Minn., holds a provisional patent for the diluent powder made from sunflower hulls, which he developed with assistance of Alan Doering, technical services specialist with the Agricultural Utilization Research Institute, Waseca, Minn. AURI (www.auri.org) is a nonprofit corporation created to improve the economy of rural Minnesota through the development of new uses and new markets for the state’s agricultural commodities.
Diluents are diluting agents used, in this case, for agricultural herbicides and pesticides. For liquid chemicals, water is the chief diluent, but dry pesticides require something else.
“A lot of powdered pesticides put on active ingredients at a very low rate, so something is needed as a carrier,” says Kresge, who holds a Ph.D. in soil fertility. “You want a dry diluent, but you also don’t want a nuisance dust that can be respirable.”
Nuisance dust from dry pesticides can be released into the air when handled, creating a potential health concern for applicators. “Someone has to apply the fungicide, but you don’t want respirable dust. You don’t want it released into the air,” Kresge says.
Powdered pesticides are especially common in the potato industry. The majority of farmers in the western U.S. and Midwest plant potato seed pieces rather than whole potatoes. The cut surfaces are perfect entry points for disease-causing fungus. To prevent fungal diseases from causing the potatoes to rot in the ground, cut pieces are sprinkled with dry fungicides. The pieces are then stored for about 10 days while a new skin naturally forms over the cut.
Currently, talc and powdered alder bark are the primary diluent ingredients used in potato fungicides, but as the supply of alder dwindles, new ingredients are needed.
Perfect powder with sun hulls
In 2003, Kresge and Doering started experimenting with a wide range of ag fibers that could be ground finely enough to work as a carrier. After nearly two years of evaluation, they developed a powder with sunflower hulls as the key ingredient because the hulls’ high-oil content reduces dust. The shredded fiber’s shape also helps hold on to small particles.
The dust-reducing quality of the diluent was tested and received high marks from the USDA Agricultural Research Service laboratory in Lubbock, Texas.
Kresge tested the ag-based carrier on several plots in Oregon in 2004, and three more plots were planted and evaluated in 2005. The fiber carrier has now moved beyond testing and into the marketplace, as seven tons of demonstration product have already been produced and another 20 to 30 tons were made for potato markets in Colorado, Florida and the Red River Valley.
Kresge, who was raised in Northeast California’s potato-growing region and has 25 years experience in agriculture as an agronomist, knows there is significant market potential for his fiber carrier in all the potato-growing states. “Potato growers are the target market because the growers are the end user,” Kresge says. “The seed-piece fungicide market exceeds 4,000 tons per year.”
Doering says the ag-fiber carrier development is a good fit since the sunflower hulls can be sourced and processed in Minnesota. “It reduces dust, plus it utilizes what is typically viewed as a waste product.”
While potato-seed treatment is the initial market, future opportunities include flea
and tick powders as well as livestock insecticides. – Dan Lemke
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