Skip to main content

Trunk Disease Projects


Many (if not all) of vineyards east of the Rockies have challenging summer time conditions that promotes develpment of major fungal diseases such as downy mildew, powdery mildew, black rot, Phomopsis cane and leaf spot, and Botrytis, we often focus our discussion on these diseases.  However, we should not forget about trunk diseases that can affect the life of grapevines. Some of the examples are: Botryosphaeria canker, Petri disease (aka Esca), Crown Gall, and Eutypa dieback. In addition, some of the other pathogens such as Phomopsis are also capable of infecting woody tissues.  

These diseases typically cause damages to the infected vines in a long timespan. Thus, the infection today may not cause any obvious damage until a few years from now. These pathogens act more like a “silent killer” and can shorten the life of the vine by 5-10 years. Thus, the prevention of these diseases will benefit you in a long run. On the other hand, if you have younger vines (up to 5 years or so), these diseases can progress rapidly and cause a decline of the infected vine within a year or two. 




Since these pathogens limit the movement of water and nutrients by infecting xylem and phloem, typical symptoms of these diseases are discoloration of leaves and shoots.  However, often time it is very difficult to diagnose what is going on because many of symptoms are very similar to each other.

To address these issues, our lab have a collaborative project with Dr. Kendra Baumgartner's group at USDA/ARS in Davis, CA.  We obtained USDA/NIFA Specialty Crop Research Initiative grant in 2012 to investigate more on these important diseases.  The primary focus of our group is to develop extension tools that can help diagnostics as well as development of management strategies.

If you are interested in our activities, please visit our project site (Note: we are still working on the hosting site, I am hoping to have it published by mid-April 2014).  In the future, our plan is to provide 1) Mobile/Web application for trunk disease diagnostics, 2) Updated factsheets for major trunk diseases, 3) Develop a new trunk disease database, 4) Offer webiners and video clips on trunk disease management, and 5) Offer in-service trainings for extension agents, crop consultants, certified pesticide applicators, etc. 

Also as a part of the project activities, I have uploaded trunk disease management guide for VA.  Please take a look at it. 

Comments

  1. The second picture depicting vine leafs with brown areas and brownish wilting leaves caught my eye. I've got this in a few areas of my vineyard and at first I thought I was fighting Downey Mildew, but these leaves didn't really look like the Downy Mildew pictures in my IPM Scouting Guide. I took pictures and was going to try and find someone that could identify what's going on. I marked the infected shoots and have been observing that there doesn't seem to be any spread to adjacent non-infected shoots on the same vine cordon. I would like to learn more and hopefully there is a way to not loose the vines or at least learn how to best manage and prevent the spread. Can you point me in the right direction to get some assistance? My vines are located in the Catlett, Virginia area.

    ReplyDelete
  2. Hi Michael,
    The best way is to send some samples (unfortunately, it has to be trunk tissue to isolate the pathogen) to VT's plant disease clinic. If you contact your local extension agent, they will assist for the submission of your sample. If you do, please put my name, along with your extension agent's name on the form so that I will also receive a report from them.

    If it is indeed Esca (aka Petri disease, black goo), chances are you can re-train the vine by cutting the infected area and promote basal buds to come out. (I.e., if you notice suckers coming out this year, you may want to keep it.) This pathogen is relatively slow growing, thus, if you rotate your trunk every 4-5 years, I think you can manage the vine. If you have further questions, please shoot me an email.

    ReplyDelete

Post a Comment

Please leave your comment here. In order to avoid spam messages, l moderate comments, thus it may take a few hours for your comment to be posted on the page.

Popular posts from this blog

2021 Pest Management Guides for grapes (UPDATED 24 March 2021)

Updated: Links below are for the 2021 edition of Pest Management Guides. The first one is for home gardens, and the second is for commercial productions. I asked them to provide by chapter (= crop) and they made changes. :) 1) Visit the page by clicking one of the links below. (It is rather a slow page. Please be patient.) 2) Scroll down until you see "Links to individual chapters." Grapes are chapter 3 for both Home (Home Fruits) and Commercial Crops (Grapes) 3) Once you get to the site, click "PDF", then "Preview", and it will open a new window.  4) Scroll down a bit, and click "Download Version" to download the file to your computer.  2021 Home Grounds  Pest   Management   Guide 2021 Horticulture and Forest  Pest   Management   Guide

Prepare for a potential rain event for this weekend.

Looks like a tropical storm Marco is moving westward, but Laura may hit our areas during this weekend. The current forecast shows (opens a new window with a link to Weather.com) potential movement to Virginia and surrounding states around this Saturday (8/29). Many white cultivars will be either ready to pick or getting very close to harvest, and red cultivars may have several weeks to go, depends on where you are what you grow. At this point in the season, the target diseases are late-season fruit rots (Botrytis, ripe rot, bitter rot, etc.) and downy mildew (on leaves). For whites, it may be a decision of when to pick, but not what to spray. If you decided to wait until the storm is over, there are several materials with a very short PHI that you may want to consider, such as Oso/Ph-D or Elevate for Botrytis and a phos acid for downy mildew. FYI: when we tested in the field, Oso plus Double Nickel combination worked well against sour rot. For reds, it will depend on when and what you

Downy, Botrytis, sulfur burn, and open house

With recent rain events and warm and humid nights, the risk of downy mildew and Botrytis are probably high in many areas of Virginia. For example, I counted seven days (at Winchester, VA) and eleven days (at Rustburg and Scottsville, VA), with downy mildew infection events in the past two weeks according to the NEWA model ( http://newa.cornell.edu/ ). It is very important to keep your vines protected, and if you think you need to have a kick-back activity against downy mildew to counteract the recent rain event that your previous spray might not have provided good coverage, add a phosphorous acid material such as Prophyt or Phostrol.  Please refer to this list of materials with short PHI since some of the cultivars are getting very close to harvest. Note: although both sulfur and copper have a short PHI, we typically do not recommend spraying these materials within 3-4 weeks of harvest due to its potential negative impacts on the fermentation or wine quality.  When some of us ended up