Good Fruit Grower

March 1

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12 MARCH 1, 2016 Good Fruit Grower C odling moths in Washington currently do not appear to be carrying resistance traits to the insecticides commonly used to control them, but researchers are a step closer to being able to identify that resistance quickly if and when it develops. Three key insecticides have been used effectively in the region for codling moth control, but the possibility of the insects becoming resistant to these chemicals is a growing concern for orchardists. A study by research geneticist Stephen Garczynski of the USDA Agricultural Research Service in Wapato, Washington, aimed to identify the codling moth's pro- teins that are targeted by each of these insecticides and to identify potential detoxification enzymes in them that could lead to resistance. Rather than using a laboratory colony of codling moths for the study, Garczynski and the research team gathered insects from the wild in the Yakima Valley. The study showed there don't appear to be any resistance changes in codling moths currently, he told the Wash- ington Tree Fruit Research Commission at the Apple Crop Protection Research Review, held in January in Wenatchee, Washington. Seeking better growing degree-days through the season, because being off by even one day can allow a significant number of larvae to enter the fruit. Obliquebanded leafroller Diapause induction is not as well studied for leafroller, but studies suggest there is a critical day length and heat factor crucial to determining the number of generations, Jones said. Some larvae go through five instars, others through six instars. Jones determined there are four periods during the season that showed significant efficacy for targeting lea- froller, and timing is everything. Shoot growth early in the season limits residual effectiveness, and in summer, residues last 30 to 50 days for treated foliage. —Applying larvicide alone at 90 degree-days is an important step in controlling leafroller. —Applying an ovicide with oil at 720 degree-days is helpful, but by itself provided the worst control of the four application windows. —Applying larvicide plus oil at 900 degree-days is the most important step in controlling leafroller, and the one application growers absolutely should not miss. —Applying larvicide plus oil at 1,800 degree-days can also be helpful, but it is more difficult to get coverage. Growers can use any three of these four windows to similar efficacy, Jones said, and hitting all four is only marginally better. "Any three window treatments is bet- ter than the old standard timing," he said. Jones said control recommendations for oblique- banded leafroller will be updated for growers for the 2016 season on WSU's Decision Aid System ( following last year's research. • Researchers are getting a head start on keeping codling moth resistance traits to insecticides in check. by Shannon Dininny • Hydro-cool directly in totes • Reduce fruit bruising • Durable and lightweight • Impervious to moisture • Chemical resistant • Twin-wall polypropylene keeps produce fresher • Easy to clean • Reusable • Made in the USA Twin-Wall Harvesting Totes Pick, process, hydro-cool, transport, and display—all in the same tote. Farm Wholesale Harvesting Totes eliminate the need to transfer your fruit from container to container. Less handling means less bruising. Available in several sizes or customize a tote for your application. Call today for special pre-order booking 1-877-476-5399 Farm Wholesale AG good fruit ad 2016 bw_Layout 1 1/20/2016 2:57 PM Page 1

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