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IPM Message for Cranberry Growers: Jun 25, 2010

June 25, 2010

Many first fruitworm sprays have gone out already and some growers may be through their two sprays before July 4th.  This is certainly way ahead of normal scheduling.  Late varieties on State Bog hit 50% oob late this week.  The second treatment goes out about 10 days after the first application, if you are using the standard fruitworm practice.  As fruits set, begin inspecting 50 randomly picked berries per acre, with a minimum of 200 berries per piece.  Check the guidelines on p. 15 of the Chart Book to determine if another spray is triggered.  Additional sprays are based on the number of unhatched, viable eggs found in the fruit. We have heard a couple reports of high weevil numbers.  Actara and Belay are your summer generation choices.  Both products are highly toxic to bees!!  Belay should be applied post-bloom.

Several growers have asked about spraying Callisto during bloom.  I would argue that spraying during bloom should be minimized whenever possible.  That being said, if you need or want to spray during bloom, you should not expect any issues with Callisto.  Avoid applying on very hot days and strongly consider the potential of the adjuvant to injure petals when making your decision.  You can wait more than 14 days between applications, so if the spray is not pressing, try to wait until bloom is mostly passed.  I have had a report of a combination Poast+Callisto backpack spray that injured new cranberry growth (Stevens).  They used 5 oz Poast, 0.5 oz Callisto, and 1-1.5 oz NIS in a 2.5 gal backpack sprayer.

The last Worker Protection Training workshop for the season will be held at the Cranberry Station on Wed June 30 from 2-4 PM.