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The Good Mite Fight


Up close and personal with a western predatory mite. 
Dealing with mites in orchards is tricky business. Some of these tiny arthropods—barely, or not even visible to the human eye—suck juice from leaves, insidiously sapping plant vigor. Other species of mites are actually an orchardist’s friends, feeding on the pest mites and other insect pests. But as WSU researcher Stan Hoyt discovered in the 1960s, spraying pesticides to control key pests like codling moth often causes pest mite outbreaks because this form of control also kills the good (i.e., beneficial, predator) mites.

Hoyt’s discovery led to the practice of integrated mite management (IMM) in orchards, which balances the use of pesticides with natural processes to keep pests in check. However, because natural systems are dynamic, yesterday’s practices must often be adapted to continue working. Trying to keep a handle on the shifting world of mites in the context of IMM are Betsy Beers, WSU entomologist at the Tree Fruit Research and Extension Center (TFREC) in Wenatchee, and Rebecca Schmidt, a Ph.D. candidate working under Beers.

“A species called the western predatory mite was predominant in orchards in the ’60s and ’70s,” said Beers. “Integrated pest management of that period incorporated a regimen of organophosphate pesticides [which are highly toxic to non-target insects and animals]. After a few years of use, the western predatory mite began to tolerate these pesticides quite well.” With orchardists transitioning from organophosphates to other pesticides, however, other species of predatory mites are gaining ground. Amblydromella caudiglans, affectionately dubbed "Caudies" by the Wenatchee researchers, have become the predominant predatory mite in 20 percent of orchards sampled.

Rebecca Schmidt, analyzing the results from an extensive campaign to sample Washington orchards for mites.  
Caudies’ favorite meal is the European red mite, the most common mite pest in apples. The western predatory mite prefers the twospotted spider mite, which is much less frequently a problem in apples. With a more varied spectrum of pests and predators, researchers need to learn more about the life history of these arthropods so IMM recommendations can be adapted accordingly. “Most of what we know about Caudies comes from a study in British Columbia from 60 years ago,” said Schmidt, which means “some of this information might not be applicable to Washington due to different conditions, food sources, and adaptation over the intervening time.”

Adding Technology to Achieve Better IMM Results

To learn more about mites for improved IMM, Schmidt and her colleagues have spent two years sampling over a hundred blocks of orchards for mites. This summer, Schmidt will be sampling additional orchards. She will then survey each orchard’s pest management consultant for data on pesticide use, irrigation, cover crops, and tree type and age. In cooperation with Dr. David Crowder, an entomologist and geographic information system (GIS) specialist working at WSU in Pullman, the information will be entered into a global network with data on orchard elevation, latitude, longitude, and land use characteristics. “GIS modeling might be able to tell us which factors favor particular types of predatory mites,” said Schmidt.

Schmidt’s prior research tells her that rearing predatory mites and releasing them into orchards is not a cost-effective pest control technique. “We need to work with nature,” she said, and GIS allows the researchers to optimize this relationship. “GIS modeling will help us determine which predatory mite species is most likely to be successful in a particular orchard, and then we can recommend orchard management practices to benefit that mite.”

For additional details on IMM at the TFREC, visit http://bit.ly/ZYJOjo.

-Bob Hoffmann

Registration Now Open for the Quinoa Research Symposium

Varieties of quinoa grow in plots at WSU's organic farm in Pullman. Photo by Brian Clark. 
Online registration for the 2013 International Quinoa Research Symposium hosted by WSU in Pullman from August 12 to 14 is now available through July 10, space permitting.

Coinciding with the United Nations International Year of the Quinoa, the symposium brings together researchers, farmers, distributors, and consumers from around the world to explore current research avenues and innovative farming practices. Farm tours will highlight field trial demonstrations on four Palouse farms. Keynote speaker Dr. Sven-Erick Jacobson from the University of Copenhagen and Tania Santivanez from the United Nations Food and Agriculture Organization will address the global potential of quinoa during the three-day event.

Quinoa has grown in popularity and is beginning to gain a foothold in the Pacific Northwest and beyond with support from a $1.6 million USDA grant recently awarded to researchers at WSU, Oregon State University, and Utah State University. Earthbound Farm, the Food and Agriculture Organization, Clif Bar Family Foundation-Seed Matters, National Institute of Food and Agriculture, FAIR, and WSU are sponsoring the symposium.

To register, as well as find a schedule of events, lodging and transportation information, and more, please visit the International Quinoa Research Symposium website: http://bit.ly/19ib90R.

-Rachel Webber

WSU Field Day Showcases New Anaerobic Digestion System Technologies


Anaerobic digester at Edaleen Cow Power LLC, Lynden, WA. Photo courtesy of Andgar Corp.

Anaerobic digestion, a biological process of breaking down organic waste material, and a suite of new tools that add value to the process, will be featured during a July 10 WSU field day near Lynden, Washington. Researchers at the Center for Sustaining Agriculture and Natural Resources (CSANR), working with commercial partners, have transformed environmental, economic, and social concerns about agriculture into a full-circle solution.

“The need to simultaneously produce renewable energy and assist growers in meeting nutrient management plans and mitigate air and water quality concerns is driving the development of these technologies,” said Craig Frear, a scientist in WSU’s Department of Biological Systems Engineering and a leader in the effort to expand a system of complementary technologies centered on anaerobic digestion.

At the Anaerobic Digestion Systems Field Day, several dairy operations in Whatcom County that have worked with WSU to develop and test these state-of-the-art technologies will open their doors to the public. The event will showcase nutrient recovery mechanisms that result in useable biofertilizers, solids separation techniques, biogas production, as well how to move from testing and demonstration into commercialization of value-added products. “Biofertilizers that are produced through the nutrient recovery process can be used by farmers as replacements for fossil fuel-based fertilizers. It’s truly a win-win,” Frear explained.

Beyond environmental benefits, anaerobic digestion systems present economic development opportunities both for dairy operations and local communities. In addition to income for producers and tax revenues, digester systems generate jobs during construction and maintenance. A new 7.5-minute video produced by the CSANR, “Anaerobic Digestion: Beyond Waste Management,” features commercial operators and Frear showing how some of these social benefits are made possible. 

The field day is sponsored by the CSANR with support from an NRCS Conservation and Innovation grant and WSU Agricultural Research Center biomass research.

Further information about the field day is available at http://csanr.wsu.edu/pages/2013ADFieldDay.

-Sylvia Kantor

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