Virginia Grape Disease Updates

 Thank you to those of you who were able to join us today. Here are some of the items we discussed. Slides from today's presentation (will open a pdf file in a new window) RSS feed address for this blog (I posted under "Resources" too) You can also subscribe via email using the menu showing on the upper left part of this blog. Google will drop the email subscription service in July, but I will come up with another way to send you reminders. Thus, if you wish to be included after July, please go ahead with the subscription service. Link to my grape disease management workshop presentation videos. Please note that the closed captioning is most likely not working. I created CC with the Canvas site we used in the workshop. If you wish to watch them with CC, please send me an email so that I can send an invitation to Canvas site. Unfortunately, I don't have time to work on YouTube version right now. I will focus more on YouTube version next year. I will keep it available f...

Upcoming virtual vineyard meetings The viticulture group at the AHS Jr. AREC will be hosting a series of four monthly, on-line viticulture meetings starting Thursday, 22 April 2021. The content of each meeting will vary somewhat and will involve extension specialists who will provide seasonal updates on vineyard management, pest management topics, and emerging weather, pest or disease issues. An initial topic of each of the 4 planned meetings will be a statewide grape development roundup gathered from our “sentinel vineyard” cooperators located around the state. Each meeting will last about 2+ hours, starting at noon.  At this point, the meetings will be on-line, but stay tuned for at least one on-site meeting which we plan to host at the AREC in late-July.  The meeting dates (noon start) are: 1)     April 22, 2021 12:00 PM (EDT) Register in advance for this meeting: https://virginiatech.zoom.us/meeting/register/tZ0pceigqTMrGdOSA5D6uvJUEfYaVZKLVER7 After registe...

Our eight years old chardonnay is about 50% bud break as of yesterday, and I am sure that growers in the south have seen buds and shoots already with the early season cultivars. Although the chance of precipitation seems to be low for a while, it may be a good idea to review Phomopsis management, just in case.  It looks like rain events that happened in the past few days accounted for Phomopsis disease risk events according to the NEWA .

It looks like our Chardonnay buds are swelling, which probably means that growers in the south and central Virginia either start to see bud break. Then the forecast is calling for rains next week. I guess it is a typical Virginia spring. One of the diseases you need to consider soon after bud break is Phomopsis cane and leaf spot. It causes minor leaf spots, which are more evident to our eyes, but necrotic lesions cause more critical damage on shoots and rachis. It also causes berry rot; however, it is not common with wine grapes because of our spray programs. Some cultivars, such as Viognier, Cabernet Sauvignon, and Seyval Blanc, are more susceptible to Phomopsis than the others. Phomopsis spores can cause infection requires water, and Phomopsis spores can germinate in a relatively cooler environment (the upper 40s). This pathogen tends to produce spores in spring from previously infected canes and cordons. Thus, springtime rain events are ideal for the development of Phomopsis. It is...