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Cranberry IPM Message

We have heard of several reports of single gypsy moth larvae; most were off-bog but one was on-bog.  We think it will be a low GM and winter moth year, but if you have had issues with these insects in the past, you should start sweeping and monitor your populations. We also had a report of 1 cranberry weevil on-bog.

Upright dieback symptoms have been reported in many beds, particularly in areas where traffic is high (e.g., loading areas) or where the vines are stressed for any additional reason. There is very little to be done for URD at this time of year.  If the disease has been diagnosed, you should plan to treat with Champ or a chlorothalonil product between April 25 through May 15 next year.

If you have flea beetles out there with numbers “too high” to count, you should spray Diazinon as soon as possible.  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.

Weevil counts are abundant on many sites.  We had counts of 18-30 per sweep on State Bog. Many bee hives are being picked up this week.  So if your bees are gone, you can spray Belay. It is highly toxic to bees. It is inexpensive and goes out at 4 oz/A. Cranberry is getting pulled from the Belay label, so you should use up existing stock when possible.

Most growers are in the midst of fruitworm and fungicide spraying. The week is looking to be very unsettled, so grab whatever spray window you can get.

Altacor is the best early cranberry fruitworm management option; it should have good residual and rainfastness.  Intrepid and Delegate can also be used. Current recommendations are to spray at 50% out-of-bloom for all varieties except Howes.

Green spanworm moths are out flying.  Do not target this stage of the life cycle for control.  Cranberry fruitworm moths are also out, scouting for just the right berry.  Now is the time to be planning your CFW management approach as 50% out-of-bloom won’t be that far away.

 Most cranberry varieties (except Howes) are approaching 20% bloom at State Bog.  This is the time to start thinking about your first fungicide application and to plan the rest of your fungicide program. Call Erika at ext 18 if you have any questions.

Reports of very high numbers of weevil have come in (for example, averages of 20 or 45). If your bees have not arrived and you do not have flowers open, you could still get in an Avaunt spray.  However, Wonderful Bees has started to deliver and hybrids have started with scattered bloom!  Remember it is illegal to spray Avaunt (choice for spring weevil control) when open blooms are present.

The past week has had some very cold temperatures and we have had reports of growers running for frost late last week and over the weekend.  We could still have another night with very low temperatures, so be prepared to run if needed.