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IPM Message for Cranberry Growers: Jul 18, 2013

July 18, 2013

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 case. 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. Admire or related products for grub control are aimed at the immatures in the soil. When adults are picked up in the net, applications should be made to target the larvae as eggs hatch. No aerial applications are permitted. Irrigate both before and after application. 

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. 

Dodder is widespread in many areas. If the dodder is attached to weeds that are susceptible to Callisto, you can try a Callisto application. If the dodder is mainly attached to cranberry, Callisto will probably not give you the control you are looking for. If you would like to try the hand-held flame cultivators for dodder control (they work well but take time to treat), call Krystal x13 or me at x21 to see if ours are available for loan. The open flame cultivator can be purchased for about $75 (many sites on internet but perhaps could be found locally too). The infrared models are more money and must be ordered over the internet. There are pros and cons to each type and we can talk to you about that if you are interested. 

Now is the good window to use QuinStar 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. 

Ferbam cannot be used after July 31 (fairy ring control). If you are using fungicides for Phytophthora control, the second application goes out 60-90 days after the first but 45 days before harvest, so some growers may be in the window to apply now. The third application goes out after harvest. Ridomil must be watered in, but not so for the other materials.