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IPM Message for Cranberry Growers: May 20, 2011

May 20, 2011

The constant rain of the past week forced several growers to use short-term floods for BHF and/or dodder control.  It was actually a good scenario as temperatures were cool and the window to spray was small or nonexistent.

If the weather holds, next week should be popping bug-wise.  Be sure to get out and sweep.  We anticipate that cranberry weevils should be out; possibly also BHF.  Use Avaunt for spring populations of weevil.  Winter moth larvae in the trees are getting quite large and if you find big larvae, sprays are probably not of much use at that point.  However, if you continue to pick up small larvae, you could benefit from spraying.  Spag may be slow to come along; we have not heard of much blossomworm, gypsy moth or false armyworm activity.

It is still a good time to apply QuinStar for dodder control.  Callisto applications can be made for other weed control as needed.  If you are chemigating either of these compounds, use 2-4 pt/A NIS or COC.  If you are applying Callisto by backpack or broadcast applicator, use 0.25% v:v.  So, in 1 gal of water, you would add 1/3 oz of NIS or COC.  Spot-treating with QuinStar, use 2 pt/A (or 2 pt in 30-40 gallons water).

If you need to spray for upright dieback, do it ASAP.  These must be applied pre-bloom.  Fungicide applications for Phytophthora control must also be made pre-bloom.  Contact Frank at ext 18 if you have any questions.