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IPM Message for Cranberry Growers: Jun 12, 2017

June 12, 2017

Reports of very high numbers of weevil have come in (for example, averages of 20 or 45). If your bees have not arrived and you do not have flowers open, you could still get in an Avaunt spray.  However, Wonderful Bees has started to deliver and hybrids have started with scattered bloom!  Remember it is illegal to spray Avaunt (choice for spring weevil control) when open blooms are present. If you missed the Avaunt window, wait for mid-late July window to manage summer weevil populations with Actara.


Growers are also finding small Spag larvae.  Intrepid or Delegate are your only options.  Scale is being monitored but we have not yet seen scale crawlers yet. Bring samples into the Entomology lab for confirmation.  Treatments for scale should be going on in the next week.


If you are using pheromone traps to time sprays for BHF, Spag or girdler, traps should be out.  Check them at least weekly 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.  For Spag, Intrepid or Altacor go on three weeks after start of flight while conventional products like Delegate or Diazinon go on two weeks after peak flight. For BHF, Intrepid or Altacor go on two weeks after start of flight, Diaz or Delegate can be timed after bloom over.


Please remember: Products containing clethodim, such as Intensity and Select, cannot be applied between hook and fruit set.  Please check the label of the product before using to refresh your memory on any other restriction.


The final keeping quality forecast (KQF) for 2017 has been degraded to POOR. Temperature and rainfall averages in April and May were both well above the required values to gain additional points in the final keeping quality forecast. Consider multiple fungicide applications on bogs with a history of fruit rot, using products proven to have good results against fruit rot. Review the timing of your applications carefully to boost fungicide efficacy, focusing on getting maximum coverage at the peak of bloom and early fruit set, before berries start expanding. This year you may also want to consider using full fungicides rates, as listed on product labels. Follow Erika on Twitter @esaalau for season highlights and IPM message updates or call me (x 18) with any questions about your fungicide program for this year.