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IPM Message for Cranberry Growers: Aug 14, 2017

August 14, 2017

Upright dieback symptoms have been reported in many beds, particularly in areas where traffic is high (e.g., loading areas) or where the vines are stressed for any additional reason. There is very little to be done for URD at this time of year.  If the disease has been diagnosed, you should plan to treat with Champ or a chlorothalonil product between April 25 through May 15 next year.

Pesticide reports are due at the end of the month for most handlers. Be sure to get yours in on time.

We have seen a few areas with scale. If you suspect your areas of dieback may be due to scale, please call Marty at ext 20 and bring in a sample for confirmation.

 Over the next couple of weeks, monitoring of weather conditions may be critical to avoid sunscald on berries. Scalding can occur with air temperatures as low as 85°F, especially on days with low cloud cover and low relative humidity (< 65%) and  keep in mind that the risk of sunscald and heat injury varies from site to site and may depend on specific bed conditions. In addition to weather, irrigation practices, fruit size, and vine density can influence the risk of scalding. Scald damage can be prevented by using overhead sprinkler irrigation to cool down the fruit. 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.

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 ziploc bags. Always request nitrogen determinations when you submit your samples.

If you are still applying pesticides (e.g., 2nd application of Ridomil or Aliette for Phytophthora), be sure to observe all needed PHIs.  Ridomil products, for example, have a 45-day PHI.

The IPM Message will now only be updated on an "as needed" basis.  If you have any particular questions or concerns, please call Hilary at ext 21 or send an email: