debor039

Upcoming meetings: A. Virginia Cooperative Extension and Virginia Tech will offer pruning workshops in Central/Southern Virginia (Amherst) and Northern Virginia (Winchester) this January. Beginning grape growers and experienced grape growers are invited to either workshop. The content will include a review of these topics: ·       grapevine dormant pruning ·       grapevine cold hardiness ·       disease management at pruning ·       pruning as a component of canopy management We will then go out to the vineyard for guided practice pruning grapevines before the meeting adjourns.   Please bring pruning shears and prepare to be outside; rain or shine.   Pruning Workshop Schedule for 2016: Date / Time:     12 January 2016     / 1:00 – 3:30 pm Lazy Days Winery 1351 N Amherst Hwy, Amherst, VA 2452 Date / Time:      13 Ja...

Please see the message below from Dr. Sara Spayd, who is an extension viticulture specialist at NCSU.  The information is probably more applicable to people in the southern VA, but we have not really seen cold temperature in the northern VA either. While we can enjoy outdoor activities in the middle of December, this warm weather is bit concerning for grapevines.  Let's hope for a gradual temperature drop in the near future... -- Please pass this on to all grape growers: I know this beautiful weather is tempting, but please DO NOT PRUNE - even hedging. Pruning helps to stimulate vine growth. I would not be at all surprised if you see grape buds in some degree of bud swell, particularly the European bunch grape varieties. Those varieties have very little chilling requirement and it was likely met in the few cold days that we have had.  The short predicted cooling pattern for this weekend will do little to harden the vines and buds for any potential cold weather in Ja...

It was very nice to see you all at the beginner's workshop held today at AHS AREC.  Here are: 1) my presentation (Google drive will open) and 2) disease management guide for non-bearing vines. I hope to see you guys in the future!!

With this week's precipitations that we (including many meteorologists) did not anticipated last week, some of you have contacted me to seek options for the late season application, especially for red-fruited cultivars that need to stay on the vine for a few more weeks.  Here's a table for late season fungicide options, with materials that has 7 or fewer PHI (it will open Google Drive's spread sheet).   The efficacy information is based on our PMG, which can be downloaded from the right hand side of the blog.  (It says 2014, but the file is updated to 2015).  Hopefully we will see the sun soon! Good luck with the rest of the season.  It's almost done!!!

I have heard from several growers that they are seeing downy mildew despite the fact that they have not seen much precipitations.  It could happen because of the humidity, especially during the night.  Warm, humid, and dark condition (just like we have been having during the last few weeks) promotes downy mildew pathogen to produce spores. In addition to these conditions, we had lines of rain storms passed in our areas in the past two days. The length of wetness due to these storms were probably long enough for downy mildew pathogen to cause infection. So, just a reminder.  If you have seen downy mildew, and you have not applied any protective material (captan, Revus, even phosphorous acid products) in the past 10 days or so, you may want to consider a rescue application of a phosphorous acid product to reduce the risk of infection that might have happened in the past two days of rains.  (Note: If you are considering harvest in a few days, I would wait until harvest....

Dr. Wayne Wilcox at Cornell University wrote an article on sour rot management on " Finger Lakes Vineyard Notes ". (The link will open a pdf file)  Please check it out.  Results from his research group is showing that 1) good canopy management matters, and 2) management of insect (fruit flies) seems to have a big impact on the development of sour rot.  Since their regions do not have issues with spotted wing Drosophila (aka SWD), even regular fruit flies, which cannot damage grape skin, can still aid transmission of sour rot pathogens.  I know some of us in VA have been managing SDW in the past few years. If you have managed SWD and have seen lower level of sour rot, please let me know.

Now the season is wrapping up, and one of questions I get often is “when to spray what to protect your crop at the last stretch”.    Unfortunately (as with everything else), my answer to the question is “it depends.”   But it won’t help anybody, so, let’s go over several potential scenarios and see one of them makes sense to you. Case 1: you are expecting harvest in 2-3 weeks I think many of Chardonnay and other early white cultivars are about to be harvested.   Luckily, around Winchester area, we have had a good stretch of relatively dry weather.   We had rain showers came in several times, but only two of them, one at 8/4 and another one on 8/20 were long enough to initiate major late season diseases, such as Botrytis.   We have three Botrytis trials, but we have not seen evidence of Botrytis outbreak.   Moreover, at Winchester area, a forecast of next rain is on next Tuesday, and it looks like a case of another thunderstorm. ...