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IPM Message for Cranberry Growers: Jul 26, 2013

Jul 26, 2013

We are at the end of the window to use Admire or related products for grub control. If your bees are off the bog, you can apply Actara and Admire if needed. Cranberry weevils (second generation) are out and abundant in some cases. The threshold for spraying is higher for the summer generation; an average of 9 is used to trigger a spray. Remember Actara is Zone II regulated and highly toxic to bees. If you are in a Zone II and use Actara, you must submit a form to MDAR within 10 days of the end of the month. Forms are available at the Station, CCCGA or on-line through MDAR's web site.

Cranberry fruitworm eggs are being picked up on State Bog, especially on the Howes. You should be scouting for CFW eggs now. Collect 50 berries per acre with a minimum of 200 berries per management unit. Repeat scouting procedure every 3-4 days until August 15. If CFW pressure is low through fruit set, it may be safe to extend your interval a little. If numbers trigger a spray, spray ASAP. 

If you receive the WI cranberry newsletter, there was mention of several new pesticides. NONE of these products are registered for use in MA for cranberry! Please check with Station staff before using any new pesticides. Sometimes products that are NOT registered for use in cranberry may still be available for purchase but it is still ILLEGAL to use them on the bogs. 

Yellow loosestrife is flowering out there now, which seems to be a bit earlier than we would typically see. QuinStar is a good option for yellow loosestrife control, but it has a 60-day PHI. Poast and Select also have a 60-day PHI. Chlorothalonil products and Stinger have a 50-day PHI. Callisto has a 45-day PHI. If using granular NPK program, 25-30% of your total N goes out at fruit set. 

If using NPK/fish program, 30-35% goes out at fruit set. If only using fish, use 25% or 50%, depending on what you've done so far.