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IPM Message for Cranberry Growers: Jun 15, 2018

June 15, 2018

We have had reports of various spanworms being picked up in nets over the past week. We have been catching a few Spag moths here and there. When managing second generation Spag, you want to target the caterpillars, not the moths. If treating with growth regulators like Confirm or Intrepid or Altacor, apply 3 weeks after the moth flight BEGINS and make at least one more application 10-14 days later.  When using Delegate, apply 10-14 days after PEAK flight.  OP insecticides like Lorsban and Orthene are NOT good choices as nearly all Spag populations are resistant.  If you held late water, do not expect benefits for Spag control other than synchronization of moth emergence.  On one LW bog, we found high numbers of black headed fireworm.  Avaunt, Delegate, Diazinon, and Intrepid are the best choices for BHF. Avaunt cannot be used on flow-through bogs.

Growers with Rutgers varieties (in warmer locations) are applying first fungicides. Try to do an “in bloom” count to properly time your first fungicide. We have many pods out on State Bog, but only our Early Blacks are in first scattered bloom.  If the weekend is warm, things may move along quickly. If you are applying Select, Select Max, Intensity or Intensity One, please note that you cannot apply the herbicide between hook and fruit set.

We continue to have multiple reports on scale. Please see the fact sheet on scales in the June 5, 2014 newsletter http://www.umass.edu/cranberry/downloads/newsletters/June.5.2014.pdf.  Effective management targets the immature stage which is mobile (crawlers). They do not have a protective covering (like the mature females) and are susceptible to insecticides. If you think you have scale, please call the Ent Lab, 508-295-2212 ext. 20.

We will be discussing scale, fruit rot, and weed management on Wednesday June 20 from 8-10 AM bogside at State Bog.  We will be offering 2 contact hours for the session.  If the weather is inclement, we will meet in the library.