As part of a wine sales and marketing degree program at Santa Rosa Junior College, I took a viticulture class. I love the earth, and have been organic gardening since I left home in the 1960s. I’ve had a whole chapter of successfully propagating African violets, and I’ve continued to have organic vegetable gardens… I’m connected to the earth, so my vit class was a complete turn on. Part of the curriculum involved learning about grape pest management.
SIDEBAR: After those studies, I continued to believe that I’d logically rather manage pests with natural, organic means; rather than synthesized, inanimate ones.
I figure if Mother Nature didn’t create it, then it’s not going to find symbiosis within my body.
I like reducing things to the lowest common denominator. That worked really well when I was teaching anatomy and physiology for the five years in that chapter of my life. If you believe that inanimate, chemical uses in our growing processes have a role, I’d rather not have your products and will seek other means as often as possible.
Now, there’s a new vine pest problem… My compatriots will find natural means; those who embrace the quickest, easiest way will find synthetic means… and off we all go. It’s called “red blotch.” Leaves just have red blotches on them, and there’s no current explanation, as of November 11, when Napa-based writer Paul Franson submitted his story to Wines & Vines.
Red blotch…
From Wines and Vines, by Paul Franson, 11/07/2012
…[Dr. James] Wolpert said the new malady is not caused by known viruses or other plant diseases. He said that plants at the Oakville Experimental Station show the condition, and that it seems to be spreading there. It may be localized, but he has also noticed similar symptoms elsewhere in Napa Valley. “I don’t mean to be alarmist,” he said, but admitted, “We don’t know what it is yet.” He added that it could be due to unique nutritional or other conditions. Instead of the deep purple of leafroll virus, red blotch causes red leaves with pink/red veins on the reverse side. The reddening appears primarily at the base of the shoots. Of great concern—particularly in a cool year like this one—is that affected vines accumulate lower sugar levels: They have at least 2º Brix less than healthy, green vines. This condition is consistent across the affected vines. The Napa Valley Grapegrowers is working with UC Davis to identify Napa Valley vineyards that may have red blotch. Growers there—or elsewhere—observing these symptoms in their vineyards should contact Wolpert at jawolpert@ucdavis.edu or (530) 754-6245. Copyright © Wines & Vines
UPDATE
From Deborah Golino, the director of Foundation Plant Services, “We have invited Dr. Sudarahana to give a lecture on the topic of ‘Red Blotch’. For those of you with questions about this newly discovered virus, this will be an opportunity to get the latest information.”
THE OPPORTUNITY
A day of learning at UC Davis entitled, “Current Issues In Vineyard Health
ONE MEETING
- WHEN: November 29: Wednesday, 8:30 am – 4:30 pm
- WHERE: UC Davis: DAVINCI BUILDING
- COST: $190 includes lunch and course materials.
- PCA units applied for
- Enroll in section #122VIT204
- Link to enroll
9:00 a.m. ~ Introduction
9:15 a.m. “New Grape Varieties With Pierce’s Disease Resistance” ~ Dr. Andy Walker, Professor, Department of Viticulture and Enology, UC Davis.
10:00 a.m. ~ Break
10:15 a.m. ~ “New Perspectives On The Transmission Of Grapevine Leafroll And Its Management By Control Of The Mealybug Vector” ~ Dr. Kai Blaisdell, Post-doctoral scholar, University of California Berkeley
11:00 a.m.. ~ “Viticulture And The National Plant Diagnostic Network” ~ Richard Hoenisch, Analyst, National Plant Diagnostic Network, Department of Plant Pathology, UC Davis
12:00 p.m. ~ Lunch
1:00 p.m. ~ “What Next Generation Sequencing Will Mean To Grape Growers” ~ Dr. Maher Al Rwahnih, Project Scientist, Department of Plant Pathology, UC Davis.
1:50 p.m. ~ “Red Blotch Disease In Napa – The Research Progresses” ~ Dr. M.R. ‘Sudi’ Sudarshana, Research Biologist, USDA- ARS, Department of Plant Pathology, UC Davis
2:40 ~ Break
3:00 p.m. ~ “The National Clean Plant Network – Healthy Grape Plant Material For Our Future” ~ Dr. Deborah Golino, Cooperative Extension Specialist, Department of Plant Pathology, UC Davis.
4:00 ~ Close
I’m so pleased to see this last session…
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