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IPM Message for Cranberry Growers: Jul 3, 2017

July 3, 2017

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. Please use the traditional cranberry fruitworm timing for Howes, spraying 7-9 days after 50% out-of-bloom.  This is still the best management strategy for this variety.  We have netted some green spanworms on an organic, low-input bog in the last week.  We have also been catching Spag moths in traps. If you are treating Spag with growth regulators (Confirm, Intrepid) or Altacor, treat 3 weeks after moth flight begins; this could be now or very soon. Make at least 1 more application 10-14 days later.  When treating with Delegate, apply 10-14 days after PEAK moth capture (usually around mid-late July).  Lorsban and Orthene are poor choices for Spag management and are not recommended.

Now is the good window to use QuinStar for yellow loosestrife control, if you can use the herbicide as per your handler. 

Dodder can be controlled with concentrated spot applications of Callisto.  It is best to apply the herbicide BEFORE dodder flowers.  Use 1-1.5 oz of Callisto per gal water plus an NIS or COC, also at 1.5 oz per gallon water.  If it’s hot and humid, use an NIS.  If it’s really hot and humid, wait until the weather breaks before applying any herbicide.  Remember you cannot exceed 8 oz Callisto per acre.  If you use 1.5 oz Callisto per gallon water, you can only treat approximately 7,600 sq ft or less than 1/5 of an acre.

Early set fertilizers can go out now for all varieties, if you have not already done so. For all but the newest varieties, if using fast-acting, apply about 50-60% of your Nitrogen in this dose. For the Rutgers/WI varieties, use fast-acting and soil-applied liquids, you should be on your second fruit set application that contains 30-35% of your N dose. Please consider using low P options whenever possible.  The first and second numbers should be 1:1 or less, like 13-13-13 or 12-7-28.