Black Rot

Black rot is caused by the fungus Guignardia bidwellii and is a very serious grape disease in Connecticut. We had a run in with black rot during the 2013 growing season in our newly planted vineyard. Guignardia bidwellii primarily overwinters in mummified berries on the soil surface or in old clusters still attached to the vine. Ascospores (the sexual overwintering spores), require free water and temperatures of 50 to 90°F (80°F is optimal, germination time is 6 hrs) to germinate. All new growth is susceptible to attack during the growing season including young leaf laminae, petioles, shoots, tendrils and peduncles. A single ascospore infection can result in the development of millions of secondary conidia in the vineyard.
A Cornell Cooperative Extension Disease Identification Sheet No. 102GFSG-D4 published in 2003 by Wayne Wilcox is very helpful. I found the lifecyle of the fungus in that online publication.:¹

Good sanitation practices in the vineyard can reduce the black rot inoculum. These practices include:

• Remove all mummies during the dormant pruning process
• Cultivate beneath the vines near budbreak to bury any mummies
• Improve control by canopy management practices that promote air circulation for drying of the leaves and fruit

For much more information, the first reference below, is the link to the publication written by Wayne Wilcox. It contains pictures of grape leaves, fruit and stems infected by black rot and is an excellent reference

References:
1. Wayne Wilcox, Black Rot, Cornell Cooperative Extension.
2. Roger C Pearson and Austin C. Goheen, Compendium of Grape Diseases, APS Press, Published by the American Phytopathological Society, 3340 Pilot Knob Rd., St. Paul, MN 55121.
3. Virginia Tech Online Guide To GRAPEVINE DISEASES.
4. Mizuho Nita and Mike Ellis, Integrated Management of Grape Diseases, Ohio State University, Department of Plant Pathology.

2011 Failla Pinot Noir Sonoma Coast

We had this 2011 Failla Pinot Noir Sonoma Coast with roast elk, potatoes and shiitake mushrooms. We purchased this bottle of Failla from the same place that we were able to find the 2008 Brewer Clifton Pinot Noir. What a lucky day that was!
We first heard about Failla wines and winemaker Ehren Jordan from Greg and Linda Pearl of Pearlessence Vineyards. The wine was clear and burgundy in color and reminded me of the cool climate Pinot noirs of Prince Edward County. To me, it tasted like sour cherries that are baked in a pie with good acidity and was the perfect compliment to our dinner.

Downy Mildew

I'm still in my self education mode regarding the fungi that can infect our vines. Earlier, I blogged about powdery mildew in Strategies to Control Powdery Mildew: Part I and followed up with Strategies to Control Powdery Mildew: Part 2. I'm also collecting the blogs that deal with fungal diseases under the tab Fungal Diseases of Grapevines.
Next fungal disease: downy mildew. Downy mildew in grapes is caused by the fungus Plasmopara viticola, an oomycete in the order Peronosporales. Spring and summer rainfall at temperatures above 50ºF releases the oospores which is the primary inoculum. The oospores form a single germ tube terminating in a sporangium that constitutes the means of secondary spread of the pathogen, when they produce zoospores. The zoospore is a small swimming spore that needs water for dissemination and grape leaf stomata for entry and penetration into the inner tissues of the vine.
These zoospores initiate secondary infections which can occur in as little as two hours of wetting at 77°F or up to 9 hours at 43°F. Infections are usually visible as lesions in about 7 to 12 days, depending on temperature and humidity.
I found a very well annotated life cycle of downy mildew at The Ohio State site. The site credits the New York State Agriculture Experiment Station. Figure taken from Grape IPM Disease Identification Sheet No. 1.

Symptoms on leaves are small yellow lesions also known as oil spots. Young berries are also highly susceptible to downy mildew. They appear grayish when infected causing gray rot and become covered with a downy felt of fungus sporulation. Berries become less susceptible as they mature, but rachis infections can spread into older berries causing brown rot, having no fungus sporulation.
More information can be found in the references listed below.

References:
1. APSnet Downy Mildew of Grapes.
2. Downy Mildew Plasmopara viticola Michigan State University AgBioResearch.
3. UC Davis IPM Online Grape Downy Mildew.

Skyping with Rodney Strong Winemaker Justin Seidenfeld at The Wine Store

Last night, we went to The Wine Store in Westerly to be part of Skyping with Justin Seidenfeld, the winemaker at Rodney Strong. The idea behind the Skyping was to taste 4 different Rodney Strong wines, the 2012 Charlotte's Home Sauvignon blanc, the 2012 Chalk Hill Chardonnay, the 2010 Knotty Vines Zinfandel and the 2010 Symmetry Meritage while Justin explained how the wines were made. Justin began the tasting with an explanation and the location of the vineyards that Rodney Strong wines are made from, since only great grapes make great wines.
I asked the question about the impact of the California drought on the vines, but Justin wasn't too concerned since their water is derived from well water. What their water is mostly used for is to protect the vines during bud break if a frost event occurs. The vines are sprayed with water which freezes, causing an exothermic reaction that releases heat, thereby protecting the young growth. Justin explained that they are in the middle of changing over from water to wind in order to become sustainable and green during these spring frost events. James Morrison poured the first wine which was the 2012 Charlotte's Home Sauvignon blanc and Justin explained that the wine was made in oak with batonnage. The vineyard is named after Rodney Strong's wife Charlotte. The next wine we tasted was the 2012 Chalk Hill Chardonnay. The wine is made in new French oak, again with batonnage. Justin also mentioned that when he went to Domaine Leflaive he learned that they put the finished wine in stainless steel tanks on it's lees until it is bottled. I could taste the oak in the Chardonnay, but it was very well integrated. We next had the Zinfandel and finished the tasting with the 2010 Symmetry

Meritage which Justin explained was a blend of the 5 Bordeaux grapes, Cabernet sauvignon, Cabernet franc, Merlot, Petit verdot and Malbec. We were able to ask Justin many more questions and he entertained us with stories about Rodney Strong. Justin is able to experiment with various grapes and is developing his own cuveé! He also explained how the weather conditions affected the ripening of the different varietals which leads to the differences in the various vintages. Justin explained that they also do tastings of other maker's wines in order to compare how their wines taste alongside their peers as well as how they compare with aspirational wines. It was an educational and entertaining evening. Kudos to James and Shannon for hosting such a good time!