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IPM Message for Cranberry Growers: Jun 4, 2015

June 4, 2015

Now is the time to be monitoring for scale. Check the June 5 newsletter for more info. Bring samples into the Entomology lab for confirmation. Treatments should be going on in the next 2 weeks. If you are using pheromone traps to time sprays for BHF, Spag or girdler, traps should be out. Use 1 trap per 10 acres and place them on the upwind side of the bog so that the pheromone blows across your bog. Check them weekly (more or less depending on flight patterns) and clean or change them as needed. Record the moth numbers. Check descriptions of adult moths in extension materials as non-target species can get caught in the traps. Intrepid, Altacor, and Delegate go on several weeks earlier (based on when flight begins) than conventional products like Diazinon (based on when flight peaks), so make sure you know the time interval for the pest you are targeting.

The Keeping Quality Forecast for 2015 is GOOD. We got 7 out of 16 possible points. For beds with little or no disease pressure, 2-3 fungicides may be sufficient. Be sure to consider other important factors (e.g. drainage, plant vigor, rot history) in addition to the KQF when managing fruit rot. Call Erika at ext. 18 if you have questions.

Poast (sethoxydim), and Select and Intensity (clethodim) can be used for control of true grasses. Chemigation is NOT allowed for any of these products. Poast should be applied with a crop oil concentrate (COC). Grasses should have at least 6-8 leaves to provide enough surface area for absorption. Select 2EC and Intensity should also be applied with a COC. Select MAX and Intensity One can be applied with a nonionic surfactant (NIS). Application of a Select or Intensity product is prohibited between hook and full fruit set, but they only have a 30-day PHI whereas Poast has a 60-day PHI. Poast has no timing restrictions, however. If you are not sure if you have a true grass, send me ( a photo or bring a sample in before treating.

We will be having a bogside workshop on this coming Tuesday June 9 from 8-10 AM at the Station with 2 contact hours offered. The focus will be cranberry fruitworm and fruit rot management. We will meet outside if the weather is nice; in the library, if not so nice.