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IPM Message for Cranberry Growers: Jul 31, 2015

Jul 31, 2015

If you have flea beetles out there and have 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. Remember Actara is Zone II regulated and highly toxic to bees. If you are in a Zone II and use Actara, you must submit a form to MDAR within 10 days of the end of the month. Forms are available at the Station, CCCGA or on-line through MDAR's web site.

You should be well into scouting for CFW eggs now. Collect 50 berries per acre with a minimum of 200 berries per management unit. Repeat scouting procedure every 3-4 days until August 15. If CFW pressure is low through fruit set, it may be safe to extend your interval a little. If numbers trigger a spray, spray ASAP.

Yellow loosestrife is flowering out there now, which seems to be a bit earlier than we would typically see. QuinStar is a good option for yellow loosestrife control, but it has a 60-day PHI. Poast has a 60-day PHI. Chlorothalonil products and Stinger have a 50-day PHI. Callisto has a 45-day PHI.

If you have patches of dodder, you can spray them with concentrated Callisto applications. Spraying before dodder flowers is much more effective than spraying after flowers or seed are present. Select and Intensity are good options to control poverty grass. Both have a 30-day PHI, but get out there soon as treatment is best before the grass flowers!

If using granular NPK program, 25-30% of your total N goes out at fruit set. If using NPK/fish program, 30-35% goes out at fruit set. If only using fish, use 25% or 50%, depending on what you've done so far.