UCONN IPM: Integrated Pest Management:UConn Grape IPM Message

Most vines examined this week were at the buckshot berry stage, with some at the tail end of bloom. The almost endless rain during most if not all of the bloom stage resulted in poor pollination and poor fruit set at some vineyards. Yellow discoloration of leaves was observed at a few locations. Several days of sunny weather could make a big difference right about now.

Diseases

This period, through bunch closure, continues to be a crucial period for scouting and for fairly tight spray schedules. With the extra rain comes extra disease pressure and more wash-off of pesticides. Phomopsis cane and leaf spot was seen this week at fairly high levels on leaves and stems at a few vineyards. I also saw downy mildew in the fruit clusters at 3 locations. So far I have not seen powdery mildew, although a major infection has been reported in Windsor and the disease model has predicted high risk through-out the state. Black rot and Botrytis are also at high risk, so be sure to keep covered with materials that are excellent for all 5 diseases. Leaf-pulling and cluster thinning are effective tools to lower disease symptoms. For the updated disease risk tables, go to the UCONN IPM website and select Grape IPM from the column on the left: http://www.hort.uconn.edu/ipm.

Insects

Gall-forming insects have shown up in 2 vineyards. At one of them it is almost certainly grape phylloxera. This will need to be treated. Galls formed by various fly species are not as “bumpy” and are not considered an injurious pest. (Pholloxera have a root-feeding phase that causes harm.) I have started to see grape berry moth in low numbers in pheromone traps. If you have had a problem with this pest, keep checking your traps. The sections of your vineyard closest to woods are the most vulnerable. Mite infestations can build up quickly at this time of year. This week’s edition of New England Grape Notes reminds us to be sure to check the underside of your leaves. Insects that will need attention now are Potato Leafhopper, rose chafer/Japanese beetle and Grape Berry Moth. If you are not on the subscription list for this invaluable newsletter, you can write the editor, Sonia Schloemann, at sgs@umext.umass.edu .

Upcoming Meetings

The Connecticut Vineyard and Winery Association Vineyard Day will be held on Saturday, July 18 2009 at the Miranda Vineyard in Goshen, CT. It will be a morning program, 10-1 PM. For more info go to: http://www.ctwine.com and click on Vineyard events.

Information on our site was developed for conditions in the Northeast. Use in other geographical areas may be inappropriate.

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