Phil Brannen
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Downy mildew was confirmed today in west Georgia (see below for photos from the producer). This is the first confirmed report this year, but as I said yesterday, it is likely out there in other locations as well. We will likely see more symptoms of downy mildew this week as the epidemic takes off. If…
Posted in: Uncategorized -
I think most producers are fully aware that recent rainfall events will increase disease levels in wine grapes. I am particularly concerned about fruit rots and downy mildew. In particular, more active materials for downy mildew are needed at this time. Though the contact materials such as Captan and Mancozeb are good materials, I think…
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We are now hitting peak bloom on many of our grape cultivars. Bloom is a critical time for disease management in grapes, and with the rainfall that has occurred this week, we are setting ourselves up for another active downy mildew and rot season. In addition, other diseases, such as powdery mildew, Phomopsis and Botrytis,…
Posted in: Bunch Grapes -
If you are really interested in learning about grapevine trunk diseases, this new journal article is for you (see link). It is a highly scientific article which covers the state of the art relative this topic. We mainly have issues with Botryosphaeria-type diseases, and I include Phomopsis in this category as well. However, we have…
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You may already be aware of this app, but I just found out about it today. The Vineyard Advisor App has been developed by Texas Tech, and it appears to largely be an IPM app. I don’t think it is that helpful in identification, so you have to largely know the organism already to find…
Posted in: Uncategorized -
Crown gall can sometimes be confused with either leaf roll virus or Pierce’s disease. In general, if a plant is a completely brilliant red, this is likely caused by crown gall or some trunk injury. Pierce’s disease and leaf roll viruses can also have reddened leaves or leaf margins, so this is a little confusing…
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Pierce’s disease (PD) is showing up in numerous vineyards on quite a few grape varieties — V. vinifera and hybrids. Vines should be scouted in each vineyard for the three characteristic symptoms of PD: leaf scorch showing marginal chlorosis and necrosis, leafless petioles “match-sticks”, and “green islands” on the canes. In advanced cases, the grapes…
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This information is a out of place relative the season, but I want to share it with you while it is fresh on my mind. Despite a wet year, some producers have experienced significant powdery mildew issues this year — some on the clusters. Powdery mildew contributes to poor grape development, but it also contributes…
Posted in: Pest management Guidelines -
Sour rot is showing up in some Georgia vineyards (see photo below), and this is really no surprise with our environment. The classic vinegar smell in the vineyard helps to identify sour rot, as other rots are somewhat similar as they initially develop. We have issues with this disease complex to some degree in most…
Posted in: Pest management Guidelines -
Presidio is no longer registered for grape downy mildew management. This is unfortunate, but Valent confirmed this information. Presidio will be removed from the SRSFC IPM guide. You can use existing stocks of Presidio, so no worries if you have it on hand at this time. Ranman has confirmed activity against downy mildew, and it…