Issue link: https://read.dmtmag.com/i/263110
In the future, growers will fi nd pesticide regulations getting tighter, not looser. by Richard Lehnert N ew invasive insect pests, such as spotted wing drosophila and brown mar- morated stinkbug, are strongly attracted to ripening fruit, and strike orchards very near to harvest. This means growers have to apply sprays in the late season when they are more likely to leave pesticide residues on fruit. At the same time that the need to spray close to harvest is increasing, consumers—and government regulators—are looking at pesticide residues ever more warily. When fruit growers spray an orchard with a pesticide, what's the risk that they may be tripped up later by an illegal level of residue? What are the chances a load of fruit will be rejected at some point, and they will incur costs of rejected fruit or other penalties? Dr. Mark Whalon, a Michigan State University entomologist, embarked on a proj- ect last year that will result, he hopes, in a useful tool for growers. He wants to create probability charts showing the risk of exceeding a Maximum Residue Limit (MRL) with 20 MARCH 1, 2014 GOOD FRUIT GROWER www.goodfruit.com Pest Management Residual life of Mustang Max Residues of Mustang Max (zeta-cypermethrin) decline more slowly when applied to cherries in California than in Michigan, research by Dr. Mark Whalon shows. 14 day PHI Time of application Residue (ppm) .25 0.2 0.15 0.1 0.05 0 California data Whalon lab data 5 10 15 20 25 30 Days after treatment Example MRL Country Max 2 E.U. Med 1 U.S. Low 0.1 Cuba Average* 1.6 *Average included the following units: U.S., Codex, EU, Canada, Japan, Korea, Taiwan. SOURCE: Mark Whalon Be aware of residues from late sprays