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IPM Message for Cranberry Growers: Aug 10, 2018

August 10, 2018

The weather has been and will continue to be very hot. Monitor as needed to make sure the vines and fruit are not lacking for water. Short irrigation periods can decrease canopy temperature by 30-40°F and avoid scalding as long as soils are not saturated and no puddling occurs. Remember that fungicide applications at this time of the year will have a very small impact on field rot infection and upright dieback.

We have had reports of YVS and flashing from Callisto. This is not unusual especially with the stressful conditions that the vines have been under for the past few weeks.  They should recover and be fine.  With YVS, the symptoms may not disappear but the vines should be ok.

If you plan to do tissue tests, collect your samples from mid-August through mid-September. You can get your samples analyzed locally or send them off to UMass for analysis. Samples should contain no more than the top 2 inches of growth (no roots, soil, runners, or fruit). Collect tissue from vegetative and flowering uprights. You typically need about 1 cup of vine tissue. Do not collect samples when the vines are wet and do not send the samples in plastic resealable bags. Always request nitrogen determinations when you submit your samples. UMass labs are having equipment issues and are presently unable to process samples. They recommend using Penn State or UMaine services until they are up and running again.  If you need quick turnaround, you should probably look for a commercial lab.

QuinStar is a good option for yellow loosestrife (should be flowering soon) control, but it has a 60-day PHI and likely has handler restrictions.  Poast, used for grass control, also has a 60-day PHI. If you have patches of dodder, you can spray them with concentrated Callisto applications.  Select and Intensity are good options to control poverty grass; treatment is best before the grass flowers! Chlorothalonil products and Stinger have a 50-day PHI.  Callisto has a 45-day PHI. Select and Intensity (grass herbicides) have 30-day PHIs as does Roundup and Actara.

If you are using fast-acting soluble fertilizer sources for the conventional cultivars, 30-40% of your N goes out at late set.

The CCCGA Summer meeting is set for August 22 at the Upland Club in Plympton. You should register with CCCGA as soon as you can if you would like to attend and have lunch.