On July 18, 2013 at the American Society for Enology and Viticulture, Eastern Section Conference in Winston-Salem, NC I attended the Symposium on Advances in Red Wine Production: Berry to Bottle. The speakers included Diego Barison (NovaVine), Tony Wolf (Virginia Tech), Michael Jones (Scott Laboratories), James Kennedy (Fresno State), James Harbertson (Washington State), Sara Spayd (NC State), and a panel of growers from NC, TN, and VA. The Symposium started off with a welcome from ASEV-ES Chair Fritz Westover.
Fritz Westover gets the Symposium started
The first speaker, Diego Barison gave a talk entitled “Latest News on Red Wine Varieties for Warm Climates”. He spoke on the need for clonal selection to preserve genetic variability, preserve infrequent characteristics, to make more complex wines, and to exhibit weaker genotype by environment interactions. One of his jobs is to look for characteristics that may be suitable for clonal establishment, such as loose clusters that minimize susceptibility to disease. Any new clones are grafted to indicator rootstocks to determine if viruses are present. Eventually microvinification and sensory analyses are carried out to see if the clone is suitable as a wine. Some of the goals he mentioned for his program are grape acidity, ripening period, color, crop load, vigor, clean plant material, adaptability to blending, adaptability to environment, and its cultivated history. He mentioned some new clones derived from Sangiovese, Montepulciano, Teroldego, Aglianico, Negro amaro, and Calabrese that may be available in the future to growers.
Diego Barison from NovaVine
The second speaker was Dr. Tony Wolf and he covered “Canopy Management Advances for Red Wine Grapes”. Canopy management is a set of practices which can be used to alter the number, arrangement and development of shoots in space and time and thereby affect the canopy and cluster microclimate. It is often aimed at improving the architecture of canopies under supra-optimal growth conditions. Common goals of canopy management are: improved fruitfulness, improved grape composition, improved wine quality potential, decreased disease incidence/severity, and to facilitate mechanization. Canopy modification can have direct and indirect effects. A direct effect is one that alters arrangement of leaves and clusters such as training system, pruning, thinning, positioning, and shoot/leaf/cluster removal. Indirect effects are those the affect the canopy density by controlling things like shoot vigor, lateral shoot development, and duration of shoot growth. This is accomplished through management of irrigation, choice of rootstock, site selection, cover cropping, and root containment/root pruning. An indicator of an out-of-balance vine is greater than 1.0 kg of prunings per meter of canopy (about 0.4 lb/ft). Desired canopy goals are 1 square meter of leaf area per kg of fruit and 12-15 shoots per meter. Other desirable attributes of a balanced canopy post-bloom to veraison in red varieties are: about 20% gaps in the canopy, 1 to 1.5 leaf layer, 3-4 shoots per foot (VSP system), 12-20 fully unfolded leaves, 5% or less active shoot tips by veraison, 50% or more cluster exposure to light on East side (less on West; maybe more for high acid varieties), few lateral leaves in the fruiting zone (less than 10 on basal 7 nodes of each shoot by veraison), and 0.3-0.6 kg fruit/meter of canopy.
Tony Wolf discussing canopy management in red wine varieties
Since these were the two “viticulture” talks of the symposium they were primarily the ones I took notes on; however, I do have a few more.
The third speaker was Michael Jones from Scott Labs. He spoke on “Stuck and Sluggish Fermentations”. The primary causes of stuck and sluggish fermentations are: nutrient deficiency, competition from wild yeast/bacteria, lack of survival factors (long-chain fatty acids, sterols), ethanol, temperature, osmotic shock, toxins, inadequate yeast populations, highly clarified must, and pesticide residues.
The next speaker was Jim Kennedy from Fresno State on the topic of “Phenol 101”. I recall this talk was heavy in biochemistry. He described that anthocyanins are largely found in the skin along with flavonols. Hydroxycinnamic acid is in the pulp. The tannins in the grape are made prior to veraison. The tannins mature along with anthocyanins post veraison. Moderate stress tends to increase phenolic quantity and quality, including high sun exposure, low nitrogen, low soil moisture, moderate canopy size, and moderate crop load. Fruit exposure to the sun is positively related to wine quality.
The next two speakers, Jim Harbertson (Washington State) and Sara Spayd (NC State) also spoke about phenols (“Improving Red Wine Color and Phenols” and “Red Wine Phenols in North Carolina”, respectively). However, I did not take any notes. There was also a panel discussion on “Issues in Red Wine Production in the Southeast”.
My colleague Mark Chien from Penn State summarized some of these and other talks from the conference. You can find that here: http://www.pawinegrape.com/uploads/PDF%20files/Temporary%20Files%20-%20delete%20often/asev%20es%2013%20notes.pdf. See the entire program here: http://www.asev-es.org/pdf/2013%20%20Program%20ASEV-ES%20full.pdf.
You might also find Mark’s discussion with Steve Menke (Colorado State) and Sara Spayd of interest on growing fine wines in the East (http://www.pawinegrape.com/uploads/PDF%20files/Temporary%20Files%20-%20delete%20often/Sara%20and%20Stephen%20-%20wine%20quality.docx.pdf).
Generally most of the talks focused on Vitis vinifera varieties, as that is where most of the research has been done. However, there was good info on interspecific hybrids and a little on muscadines as well. I would encourage anyone with an interest to join ASEV-ES. It is relatively inexpensive and the information that comes out of the meeting is great. Plans are in the works to update the webpage, create a newsletter, and get involved with social media (primarily facebook). If you are interested in more information and how to join go here: http://www.asev-es.org/index.php