As of May 12, we had 24 possible frost nights; 8 were called as dangerous and 7 as possible. 9 nights had no frost predicted. The recent string of frost nights may contribute to waterlogged areas on the bog, so improving (managing) drainage is very important. Proper soil drainage results in optimal aeration of roots, healthy vines and improved fertilizer use efficacy.
Cranberry IPM Message
There have been reports from early scouting of very small larvae; they are likely green spanworm or winter moth. It is very hard to tell them apart when they are so small. We have also had reports of weevil, but mostly on edges near the woods. We would not recommend spraying right now anyway for high weevil numbers.
Upright Dieback (UDB) continues to rule the day. Orangey-brown dead uprights scattered throughout the greening up vine is an indication of this fungal disease at work. Pictures below show this damage on Stevens and Early Black. All the samples we received with typical UDB symptoms tested positive for UDB pathogen (Phomopsis vaccinii) in lab plating.
Frost update (from Tuesday April 20): EB and H at 20F (white bud stage); BL, ST, and super hybrids at 22 F 9white bud). We had accumulated 99 GDD as of Tuesday April 20.
Frost Update. As of Thursday April 15, we have accumulated 86 GDD (the threshold for frost to start according to the Dee model, using 44F as base T, is 100 GDD). Also note we reached the long day mark on April 7th. For the most recent reports and photos, go to https://ag.umass.edu/cranberry/frost-tolerance-reports.
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...
We have rescheduled our April Pesticide Safety Meeting to online via Zoom for 2 nights next week, the 18th and 20th, 6-8 pm. Agenda will be different for each night.
Flea beetle is out (couple spots with high numbers and damage) and more root stress/heat issues have been reported.
It’s a good time to treat for Poverty Grass and other warm-season grasses. Our grass herbicides are much more effective when applied before the grass flowers. Remember to add the proper adjuvant with the herbicide.
Some yellow vine syndrome symptoms are showing up. This is not unexpected as we see this when vines are under stress, usually from heat or water imbalances. There is not much to do at this point except to monitor soil moisture and irrigate...
