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IPM Message for Cranberry Growers: Jun 15, 2010

June 15, 2010

Clean Sweep Consulting reported sightings of second generation black-headed fireworm; the larvae are out.  Plan your management based on moth flight and choice of compounds.  Brown spanworm larvae may start to show up soon.  Look for thin, thread-like larvae on the rim of the sweep net.  Check pheromone traps weekly and change lures about every 3-4 weeks as needed.  Several of our new products like Delegate, SpinTor, Belay, and Entrust are highly toxic to bees, so spray these products when bees are not actively foraging.  Toxicity does drop once the spray dries.  Cranberry fruitworm management is based on % out-of-bloom and some varieties have pea-sized fruit out there already.  Try to get 2 estimates BEFORE 50% oob (rather than just 1); it makes your estimate more accurate.  See page 15 of the Chart Book on calculating % oob. 

Remember, only 2 Callisto applications are permitted each season, not to exceed 16 oz/A product for the season.  Many growers will be getting ready for their second fungicide application.  These are applied at 10-14 day intervals; try to stay closer to the 10-day interval if possible.  If you have fairy ring, ferbam applications are made June-July.  This is applied as a soil drench.  Fertilizer applications can be made during bloom.  If using NPK materials, about 25-30% of the total N is put during bloom.  If using a fast/slow combo program, 60% of total N goes out at bloom and if using an NPK/fish program, 30-35% of total N goes out now in the form of NPK.

The last Worker Protection Training workshop for the season will be held at the Cranberry Station on Wed June 30 from 2-4 PM.