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RF Pest Control, Stripe Rust, Forests – WSU’s On Solid Ground – June 27, 2012

Posted by | June 27, 2012

The Heat Is On: WSU Food Engineer Works to Commercialize Radio Frequency Treatments for Insect Pest Control

Washington State University Food Engineer Juming Tang examines a thermal image of a sample of lentils treated with radio frequency energy for insect pest control.
Washington State University food engineer Juming Tang examines a thermal image of a sample of lentils treated with radio frequency energy for insect pest control. Photo by Nella Letizia, WSU.

The irony probably wasn’t lost on Washington State University food engineer Juming Tang. Tang recently opened a bottle of lotus seeds to put in soup and smelled mold, a telltale sign that insect pests had already begun eating without him. Larvae hatched from eggs laid in the seeds create a moist environment for the mold to grow in—and to release toxins. Tang and a multidisciplinary, multistate team have been working for the last 12 years to develop and commercialize a method of treating nuts and legumes with radio frequency (RF) energy to combat such pests.

“People think that prepackaged dry food is safe, but this may not always be true,” Tang said. “RF treatment right after seeds are harvested but before storage can control pests before the larvae hatch or at a very immature stage. We believe it’s going to be a big thing.”

The nut and legume industries need a more environmentally friendly means of controlling such insect pests as codling moth, naval orangeworm, Indianmeal moth and cowpea weevil. In 2005 the U.S. Environmental Protection Agency phased out the industries’ main chemical fumigant used in postharvest pest control, methyl bromide, because of its harmful effects on the earth’s atmosphere.

Other nonchemical pest control methods exist—controlled atmosphere treatments, cold storage, conventional heating and irradiation—but have drawbacks, Tang said. According to his latest research, the limitations of these RF alternatives are significant. Controlled atmosphere treatments, where oxygen, carbon dioxide, nitrogen, temperature, and humidity are regulated, require exposure times of several days. Cold storage may take several weeks to kill insect pests. Conventional heating, including forced hot air and hot water treatments, cuts exposure time to hours, but can also cause external and internal damage to agricultural commodities. And irradiation, at the low levels needed to maintain food quality, merely sterilizes insects rather than killing them.

RF treatments, on the other hand, can achieve the same insect mortality rates as other methods in a shorter time, Tang said. RF treatment systems generate high-frequency electromagnetic waves that cause agricultural products—and insects—to heat rapidly. Shorter exposure times have the added benefit of not degrading food quality.

Read the rest of this story on WSU’s agricultural news web site »

WSU Stripe Rust Website Alerts Growers to Threats, Management Strategies

Stripe rust can cover the length of the wheat leaf, causing significant crop losses. Photo by Stephen Guy.
Stripe rust can cover the length of the wheat leaf, causing significant crop losses. Photo by Stephen Guy.

Pacific Northwest wheat growers now have access to a website that provides current stripe rust levels in their area, as well as tools to help them manage the fungus. Dr. Xianming Chen, USDA-ARS research plant pathologist and WSU adjunct professor, compiles the information from regional reports and his own field surveys. The Stripe Rust Alert site is available at http://striperustalert.wsu.edu/.

Stripe rust, a foliar disease that can spread rapidly through the air, caused significant losses to wheat crops in 2011 due to the cool, wet conditions favored by the disease. Chen’s May 23 report indicated that stripe rust is much less prevalent in the Pacific Northwest this year, but another threat faces growers: unnecessary spending on fungicide applications from reliance on last year’s recommendations. Fungicide applications can cost between $5 and $20 per acre, so farmers can realize significant savings if they withhold unnecessary treatments. Chen’s June 8 report, however, demonstrates why growers need to stay tuned.

In addition to assessments of stripe rust prevalence and management comments, the site features charts with wheat varieties and their resistance to stripe rust, allowing growers to factor resistance into their management plans. While the site focuses on the Pacific Northwest, it also reviews the stripe rust outlook in other states. In the future, Chen will add more information about stripe rust and its management for both growers and scientists.

Growers can also receive stripe rust alerts via email by contacting Chen at xianming@wsu.edu.

WSU’s Forest Owners Field Day Focused on Multiple Goals

Emily Burt, former Extension forester, points to a canker on a branch, which should be pruned for the health of the tree. Photo by Bob Hoffmann, WSU.
Emily Burt, former Extension forester, points to a canker on a branch, which should be pruned for the health of the tree. Photo by Bob Hoffmann, WSU.

How can I reduce wildfire risks on my property? How can my forest land generate income without depending on a timber harvest? And what kind of tree bark smells like butterscotch? These were just a few of the many questions that Northwest landowners asked, and had answered, at the June 16, Forest Owners Field Day near Newport, Washington. Andy Perleberg, WSU regional forestry specialist and organizer of the event, was pleased that 275 landowning family members turned out.

While various forest landowners attending had different priorities, including timber harvest, wildlife habitat enhancement, and environmental protection, all were able to benefit from the field day by learning about

  • better road maintenance;
  • better personal safety;
  • reduced wildfire risk;
  • improved forest health assessment;
  • reduced impacts to water quality and wildlife; and
  • better utilization of all forest products.

“In the state of Washington, 215,000 individuals and families control 5.8 million acres of non-industrial forest land,” said Perleberg. “Our field days are where many of them get their start in forest management.”

Read the rest of this article on WSU’s agricultural news web site »