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Cutting-edge IPM

Posted by struscott | October 7, 2009

What gives Washington the edge and makes it the number one producer of sweet cherries, fresh pears, and produce 60 percent of apples sold in the United States?

Jay Brunner, director of WSU’s Tree Fruit Research and Extension Center in Wenatchee, Wash., started his discussion on pesticide alternatives in tree fruit production and management and their relevance to Washington State University by asking the Agricultural and Food Systems 101 class this question.

Brunner went on to tell the class about Integrated Pest Management (IPM), which is an approach to control pests by applying the principles of ecology to manage the agro-system. IPM also considers the economic, social and environmental effects pesticides have. IPM uses five tactics: biological, chemical, behavioral, cultural and genetic.

Brunner said the chemical portion of IPM is about pesticides. In 1996 the Food Quality Protection Act was passed, which looked at the risks of pesticides. Brunner said since the Food Quality Protection Act was passed, there have been 26 new, safer pesticides registered. He said although these new pesticides are safer, they are more expensive and less effective.

WSU is involved in the research of new pesticides, by acting as an unbiased evaluator. Most pesticides are developed by private companies. These companies then approach universities to evaluate how the new product will fit into a pest control program. WSU evaluates the pesticide by determining the efficacy of the new product, how to use it to optimize pest control and other factors.

Dain Craver, an organic grower and consultant, who spoke with Brunner, said IPM is very important. He said although many growers were reluctant to change because of costs, most progressive growers now use IPM.

“It’s not black and white, there is a lot of gray area,” said Craver.

Brunner said biological methods for pest management include mating disruption, which uses pheromones as a pesticide. Pheromones are a chemical produced by female insects to call a male for mating. Dispensers placed in trees release pheromones, confusing the male and making it difficult for him to locate the female.

“In order to test this and show growers how this worked, we got funding to do an area-wide control approach,” said Brunner.

Pheromones were used in areas near Chelan, Wash. Brunner said by the third year of the experiment, 80-90 percent of the traps had no codling moths, which are the key pest in apple orchards. He said another benefit after three years was the damage from the moths was almost undetectable. The number of insecticides used also decreased by 70 percent.

“This demonstrated that pheromones will work for codling moths in a pest control program for apples,” said Brunner.

“Without pheromones, we couldn’t be the organic growers we are in this state,” said Craver. He recommends the use of pheromones to all growers.

Another biological method of IPM is the use of natural enemies to reduce pest populations. Brunner said the reason this is great is because it is a free environmental service, which is why WSU is interested in this method. He said natural enemies allow fewer pesticides to be used. Brunner said in order for this to work there must be some population of a pest for the enemy to eat. Because of this, Brunner said natural enemies are not good for key pests, but rather secondary pests. Secondary pests are insects such as aphids and spider mites that do not directly attack the fruit, but eat the foliage instead.

WSU received a federal grant of $2.4 million to enhance biological control in Western orchards. The goals of this project are to determine the impact of new reduced risk insecticides on natural enemies, develop new monitoring methods to measure the presence of natural enemies in orchards, and to develop predictive models so growers will know when natural enemies are present and when to avoid pesticides that will affect them.

Craver said in organic orchards natural enemies completely control secondary pests, because they have nothing to spray for them.

“I think this is the part that rocks,” said Craver. “I think it’s a great deal.”

By Whitney Parsons, Marketing and News intern