Friday, February 23, 2018

Slides from the 2018 VVA meeting

Thank you again for those of you attended one of my sessions.

Here are links to my presentations. It will open PDF files on Google Drive.

1) Interactive grape disease management

2) Advanced topic in grape disease management: Fungicide resistance

Please note that we will have more meetings coming up:

16 March 2018
Pruning workshop at Breaux Vineyards (Northern Virginia)

17 April 2018
Vineyard IPM workshop at Early Mountain Vineyards (Central Virginia)

6 June 2018
“Beginner’s” Grape Growing workshop
Virginia Tech’s AHS Jr. Agricultural Research and Extension Center, Winchester VA

We hope to see you there!

Thursday, February 15, 2018

Change in Presidio label: grape is no longer listed.

The label of Presidio has been changed, and unfortunately, the grape was removed from the list of hosts. This means that we no longer able to purchase Presidio to control grape downy mildew.

If you already have it, it is still legally OK to use it for the grape, as long as you keep the original label. (and if you do, please make sure to mix with another mode of action such as mancozeb, captan, copper, since the active ingredient for Presidio is known to have the fungicide resistance issue, and required by the label to mix.)



Thursday, February 1, 2018

Disease considerations at pruning time 2018

Here's this year's handout for pruning time disease considerations (this link opens Google Drive with this year's recommendation for trunk disease management). As I noted in this handout, the first line of defense against trunk diseases that may infect through pruning cut is a cultural control. Make sure to pick dates when you are expecting several days of dry weather.

In this handout, I refer to Topsin-M as a choice of trunk disease management, especially for Botryosphaeria canker, which is very common in our area. The product has been transferred to a new company in 2017, and there are changes in the label. [Note: The US distributor is still the same (UPI), thus, I do not think it will affect where you can purchase the product.] 

If you are using Topsin-M for pruning wound protection, please update your label. You can download the new label by clicking this link (will open Google Drive).

If you are pruning, and wondering whether you can protect pruning wounds from infections by trunk diseases, there is a supplemental label of Rally for control of various trunk diseases (Botryosphaeria, ESCA, and Eutypa).  

You can apply them with a sprayer or as a paint.  It would be a very good idea to use them, especially when you are making a big cut.  The timing of application would be soon after pruning and before a rain. 

Also, double pruning (early winter rough cut followed by the final cut in early spring) showed to reduce 95% of trunk disease in a CA study.

Also, speaking of trunk diseases, I have been involved in a research effort to develop management strategies for various trunk diseases. Please check our project page which contains not only research reports, but also extension information, such as disease keys, management guides, and economic tools to estimate the benefit of trunk disease management over the life of a vineyard.