debor039

It's bit off-topic for this blog, but we have a series of presentations at a local Master Gardener class tonight. Here are slides and handouts for the meeting. The major topic is plant pathology and we cover signs and symptoms of diseases, abiotic disorders, nutrient management, plant disease management, and plant sample submission tips. Thus, some of regular audiences of this blog maybe interested in too. If you click on the link, it will open a new window for Google Drive that contains a PDF file of each presentation. Introduction to Plant Pathology, and Plant Disease Management Fundamentals (Two presentations in one)  by Mizuho Nita A table of over-the-counter fungicides and their target grape diseases Plant Abiotic Disorders  by Charlotte Oliver  Nutrient Management  by Amanda Bly  Explanation of Soil Tests (a link to VCE publication) Plant disease Clinic Sample Preparation and submission  by Charlotte Oliver  If you are attend...

I have several presentations at the upcoming VVA meeting. Here are handouts for my presentations. If click the link, it will open a new window for Google Drive that contains the handouts. All files are in PDF format. 1) Fundamentals of integrated grape disease management 2) Grape pathology updates 3) Low input fungicide regimen and cultivar selection for disease management in southeast VA The last presentation is based on my recent book chapter, which is free for you to download. Please click the link here to visit the publisher's website. Unfortunately, I won't present these talks, but Tony and Charlotte (my PhD student) will present them on my behalf. I will be at each presentation to answer any questions you may have. I will also be around throughout the meeting. I am looking forward to see you during the meeting!

First of all, Happy New Year! I hope you had a nice holiday season. Here's a table of upcoming vineyard meetings. 2017 Upcoming Virginia Vineyard Extension Meetings Program name Location Meeting details and registration information 24-Jan Pruning Workshop Honah Lee Vineyard, Central Virginia https://goo.gl/forms/J48R5RKwlFg76ckw2 23-Feb New Grower Workshop Charlottesville http://www.virginiavineyardsassociation.com/2016/12/winter-technical-meeting-registration-opens/ 24-Feb VVA Winter Technical Meeting Charlottesville http://www.virginiavineyardsassociation.com/2016/12/winter-technical-meeting-registration-opens/ 7-Mar Pruning workshop Breaux Vineyards, Northern Virginia More information coming soon 16-Mar IPM meeting – Pre-season training for vineyard pest management Early Mountain Vineyards, Central Virginia More information coming soon 9-Mar...

It has been pretty wet week so far. At Winchester, we observed about 11 hours of wetness on the 26th with an average temperature of 64F, 50+ hours (and counting) from the 28th to today with an average temperature of 61F. It is certainly long and warm enough for Botrytis infection. Whether we require a fungicide application for Botrytis or not at this point depends on several potential factors. The first one, of course, is whether you had a previous application or not. If you had a previous application to cover these rain events, you probably do not need to be concerned much. The second one is a time to harvest. If you still have several weeks to go, you may want to consider an application, but if you will harvest within a few days, I am not sure an application of fungicide will help you much since we do not have any curative materials for Botrytis. Whatever we spray at this point will be good against future infections, but not the infection happened already. The third is cultivar. Chan...

Maybe I should keep posting that rains are coming... Each time I do, it looks like rains disappear. ;) If you have not subscribed to the email list of Dr. Tony Wolf, who is our viticulturist, please do. It always have a wealth of information. In his latest newsletter, he explores potential reasons why some of cultivars are stalling on ripening process this year. Our Chardonnay is still stuck at 19 Brix or so too! The below is a link to his newsletter, but it typically take several days for the newest one to appear. Thus, the best way is to subscribe to his email list (the instruction for subscription is listed on the page too). http://www.arec.vaes.vt.edu/alson-h-smith/grapes/viticulture/extension/VN_options_index.html

Well, I was hoping that the rest of the season would be nice and sunny, but I was little naive. Looks like some portion of VA may be affected by tropical storm Hermine. Plus, probably due to the hot several weeks with no cooling time during the night in August, some cultivars have been very slow to ripen. I was bit surprised to see our Chardonnay is still around 17 Brix this week. Thus, I complied a list of fungicides with relatively low PHI (7 days or less). I cannot cover every single fungicides out there, but I tried to cover common ones. Please click here to download the table from Google drive. NOAA's precipitation prediction for Harmine as of 2 Sept. 2016

I heard that some of early cultivars are ready to be picked on 7-10 days.  Looks like no tropical storms to worry, yet... (crossing my fingers!) There have been frequent thunderstorms went through our area, and some of them (like the one we had last night) resulted in a significantly long wetness event (8 hours). These wetness events, especially the one happens overnight, are preferred by downy mildew pathogen since they produce spores in dark, moist conditions. Please check my previous post on late season downy mildew . As usual, protection is the best approach.  If you have seen some downy mildew on foliage, it would be best if you can mix a protective material (e.g., copper, captan) with a phosphonate (Prophyt, Phostrol, etc). If there is heavy downy mildew already happening, please do not use Ridomil (metaxel) products because they are known to be overcame by the downy mildew pathogen. Some of reds are probably going through veraison, which would be a good timing for your ...