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IPM Message for Cranberry Growers: Jul 3, 2020

July 3, 2020

It is time to being planning for your first Altacor application targeting Cranberry Fruitworm eggs.  Even most large-fruited varieties have still not reached 50% out of bloom, but berries bigger than pinheads are easy to find.  It is a philosophical question whether to spray a bit early or to wait it out.  Cranberry Fruitworm moths are out laying eggs, but if you treat now, all the pods or flowers remaining will not be protected with Altacor when you wait the 7-10 days for your next application. 

Two cases of the tiny brown beetle that causes dark spots the size of a truck on the bog have been reported.  It is NOT fire beetle or rootworm, but is it a Cryptocephalus species that we have seen several times before.  The beetle is really small, about 2 mm - much smaller than a weevil.  If you sweep through the spot you will get dozens of them.  Treatment, if necessary, will have to wait until after bloom.

If you are comfortable spraying during bloom, you can treat poison ivy with concentrated Callisto sprays now.  Best results occur if you treat twice in the same year and then repeat the following year.  Sprays of Intensity/One can also be made during bloom.  I would caution against using any crop oils during bloom and/or during hot humid conditions.

Fertilizers for EB and Howes can go out at early fruit set, targeting to apply 50-60% of your total N in this application.  Your last app of 30-40% can go out at late set. If growing Rutgers or U-WI varieties, target about 30-35% of your total N at first fruit set.  Follow 7 days later with another 30%, followed by the last 20% 7 days later.