Back to top

IPM Message for Cranberry Growers: Jul 8, 2011

July 8, 2011

Many first fruitworm sprays have gone out already and some growers may be applying their second spray soon.  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.

Avoid applying pesticides on very hot days and strongly consider the potential of the adjuvant to injure petals when making your decision.  Last year, it was reported that combination Poast+Callisto backpack spray that injured new cranberry growth (Stevens).  They used 0.5 Poast, 0.5 oz Callisto, and 1-1.5 oz NIS in a gallon of water.

If you see diseased dodder or yellow loosestrife dying, please contact Frank at ext 18 orfcaruso@umass.edu .  He wants to collect samples as part of a project funded by CCCGA to investigate possible new mycoherbicides.