debor039

Bud break for our younger (2-3 years old) Chardonnay happened around 4/20/2018, and for older Chardonnay, it was the last weekend, (4/27/2018). Looks like we are about 1-2 weeks behind of a "typical" spring. But as with a typical spring, rain comes when grapes break buds! Looks like we will see some precipitations this weekend.  Please make sure to have a good protection against Phomopsis as we discussed in the previous post.   Let's hope that our season will be as good as 2017.

As of today, it is about 10% bloom at our Chardonnay plots. Since bud break was about 2 weeks ahead of a typical year, things are moving along as we would expect. Of course, bloom in VA almost always has to happen in rain... As for bloom time disease management consideration, please refer to the previous post. From this point on, 4 to 5 weeks will be a critical period for management of downy mildew, powdery mildew, and black rot. Please make sure to keep your vines covered. Once again, providing a protection is much better and easier than playing a catch-up, especially if it comes to grape disease management in VA. You can use protective materials such as mancozeb, copper, and sulfur as your backbone, and add more specific (and often locally systemic) materials. Some of these materials have efficacy against multiple diseases (either by itself or through the combination of two materials). Examples are DMI, aka SI (FRAC = 3), e.g., Rally, tebuconazole, Mettle, etc. Inspire super is a...

It looks like the 2017 season for us has officially begun. Our 8 years old Chardonnay at Virginia Tech's Winchester AREC was about 10% bud break as of yesterday. Despite a warm winter, a colder spring might have kept things slow (I am not complaining!) Once again, the important disease at this point is Phomopsis cane and leaf spot. Please refer to my previous post about Phomopsis management. Also for our Chardonnay plot, we have a chronic issue with climbing cutworms. Since we know the location of our vineyard where we always see some damages, we typically apply an insecticide to the panels of vines that is facing a wooded area. Without spraying the whole vineyard, it seems to provide adequate control. Good luck with the 2017 season. I will post key disease management tips as the season moves along.

Our 6 years old  Chardonnay had 100% bud break today (4/22/2015)!  Looks our our season has officially started. There has been a few email inquiries came to my inbox about climbing cutworm.  We have applied Intrepid to "hot spot" which is a few panels facing wooded area for us.   Please refer to Doug's posting and UC IPM for more information.

A line of rain went through Winchester area resulted in 10 h of wetness with an average of 69F.  It was downy and low Botrytis risk event.  Please refer to the comments on previous posts on late season disease management. FYI: Our Chardonnay berries are hitting 20-21 Brix and pH is getting near 3.0.  We will see what the forecasted thunderstorms towards the end of this week will do for it...

Many people in northern VA are about to see blooms (our Chardonnay vines are trace bloom as of June 2 nd , the one on the picture is one of the few with many open flowers), and I am sure rest of regions are going through bloom by now.   Therefore, many of us are in the critical time for cluster infections by downy mildew, powdery mildew, and black rot.   Bloom time is also critical period to prevent Botrytis, ripe rot and Bitter rot, because pathogens of these diseases can infect flower parts and come back later. We do have materials with kick-back activities against downy (Ridomil products, Phosphonates, etc.) and black rot (myclobutanil, etc.), but infection on flowers and young fruits can happen very fast.   Unless we have a very dry season, this is the time where you have to be proactive.   Thus, what I recommend often is use of protectant materials to protect tissues for 4-6 weeks for V. vinifera varieties, and 3-4 weeks for V. labrusca varieties, which should ...

Our 5-yr old Chardonnay is about 50% bud break stage as of today. At this time of the year, the number-one concern is Phomopsis cane and leaf spot. They produce spores on old infected cordons and trunks during the spring, and they can infect tissues even if temperature during a rain event is in 40s. Only option we have against this disease is a protective application of fungicide, such as mancozeb, captan, and Ziram. A QoI fungicide such as Abound and Pristine are also effective; however, I would recommend keeping them for the later part of the season.  Since they can be active under cold rain event, my recommendation is to protect even when shoots are about 1-3 inches long. The decision to spray for Phomopsis also depends on the history of the vineyard. The vineyard with previous history of Phomopsis tends to carry the same issue year after year.  You are probably wondering about the risk of Phomopsis from this week's rain.  At our vineyard, we receive...

Our 5-yr old Chardonnay is still in the mitten stage, only a few broke buds.  At least we do not see the risk of frost in the 10-day forecast... Once they broke buds, the first disease to be considered is Phomopsis.  It is because a) Phomopsis produce spores from previously infected canes, cordons, and trunks, b) the spores are active even in 40's, and c) young leaves and clusters are susceptible to infection.  The best approach is use of Mancozeb, captan, or Zirum as a protective application.  QoI fungicides such as Abound and Pristine works too, but you want to keep them for later in the season.