We have been hearing about many bogs with vines in distress coming out of the winter. Some bogs have leaf drop, some have dead vines and dead spots and some are showing dieback of uprights. More than 20 samples have already come into the Diagnostic Lab. We do not know yet if it is abiotic or biotic stress or some combination. As these early samples come in for diagnosis and we find out more information, we will post all updates on the IPM message (phone and website). Contact Leela for more information at suppala@umass.edu. Leela is working on a revision of the fact sheet for Upright Dieback and it should be available soon. We will post it on the web site when it is ready.
As of Friday April 9, we have 64 GDD towards frost protection according to recent work by Peter Jeranyama. Daylength is also important for triggering frost protection according to the model. We are at about 14 hours right now. The last weekend was cold and some growers ran and some did not. Conventional wisdom would say it was still early to be frost protecting and the recent model would also confirm that approach as well. Please reach out to Peter if you have further questions. peterj@umass.edu
Zeus applications should be made before the cabbagehead stage; many applications are going out now and early next week. We do see damage/injury increasing for applications made after cabbagehead stage. The rate is 12 oz/A and can be used under the Special Local Needs label (SLN), which is available on our website (under Services) or at your point of purchase. Zeus controls moss (takes a long time to see symptoms), some grasses and likely other weeds that we are not yet aware that it controls.
Our Pesticide safety meeting will be held on Tuesday April 27 and April 28, from 8-11 am. Please contact Robyn at rmhardy@umass.edu to register. See the March 29, 2021 newsletter for more information, https://ag.umass.edu/cranberry.
