MSU Workshop to Teach Grape Pruning Basics

The Mississippi State University Extension Service invites grape growers in the state to a pruning workshop to be held Feb. 3 in Beaumont.

The event will cover the basics of vine anatomy and pruning techniques for bunch grapes and muscadines. After the presentations, in-field demonstrations will show participants correct pruning techniques. Novice and seasoned growers are invited to attend.

The event will be held at the MSU Beaumont Horticultural Unit in Perry County from 10 a.m. to noon. There is no cost to attend, and no preregistration is required. Registration will begin at 9:30 a.m. Participants are encouraged to dress for the weather expected, as part of the workshop will be spent outdoors.

The Beaumont Horticultural Unit is located at 478 Highway 15 in Beaumont. Contact Eric Stafne at 601-403-8939 or eric.stafne@msstate.edu for more information.

Measuring Grapevine Growth

For three seasons I have had a study going on how grapevines respond to producing a crop in the season after they were planted.  In 2013 I planted three cultivars — Blanc du bois, Villard blanc, and Miss blanc.  In that first season I was able to get them trained onto the cordon wire (single wire high curtain system). In season two I had three different treatments: removal of blooms, removal of fruit at veraison, and harvested fruit.  In season three, all vines were harvested (some even going to produce a commercial product, but that is a discussion for a later post) and today I measured trunk calipers.  I have not analyzed the data yet, but I will look at cultivar and treatment effects on vine trunk size.  Below is a photo of the process:

Caliper measurements on a grapevine trunk

Caliper measurements on a grapevine trunk

I have a little more data to collect and then I will be able to start analyzing the data and writing up the results. This study was also done in Oklahoma before I moved to Mississippi, only with different cultivars. It will be interesting to see how the results compare. Growing grapes is expensive and growers need to start recovering expenses quickly. If grapes can be harvested starting one year earlier then the time to recover initial capital outlay will be shortened.  However, we need to make sure that has no lasting impact on vine health, thus this study. Since I couldn’t find any other studies like it in the literature I decided to answer the question myself.  And soon, I will find out the results.  It is exciting!

Netting Grapevines Against Birds

Last year I had problems with birds destroying some grapes before I had the chance to harvest them (full disclosure: I had several conferences last year that I attended while it was close to harvest time.  I rolled the dice that the fruit would still be there when I got back — no such luck). This year I am taking no chances!  Last week the bird netting went up on two of the four rows in the vineyard and this week the other two will be covered as well.  Since the vineyard is so small, it was relatively easy to put the netting over the rows and secure it.  Below are a few photos (taken by Richelle Stafne) of the process.

Throwing the netting over the row.  It helps to be tall.

Throwing the netting over the row. It helps to be tall.

Pulling the netting over the vines to make sure it covers the canopy.

Pulling the netting over the vines to make sure it covers the canopy.

Securing the netting by using zip ties. Other materials can be used such as string, twine, or bread ties. The netting was tied to the irrigation wire with the zip ties.

Securing the netting by using zip ties. Other materials can be used such as string, twine, or bread ties. The netting was tied to the irrigation wire with the zip ties.

The job is finished and we admire our efforts while sweating in 90+F heat and humidity.

The job is finished and we admire our efforts while sweating in 90+F heat and humidity.

The netting will remain on until harvest.  Once all fruit is harvested it will be removed and stored for next year.  Netting is an added expense to the vineyard and it makes management more difficult, but it is a necessity to protect the fruit from birds. There are different kinds of netting, some will last longer than others (and hence are more expensive), so it depends on an individual managers needs which kind to purchase.  Tractor implements are available to help with this process in large-scale operations.

2013 ASEV-ES Red Wine Symposium

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

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

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

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

 

The VitisGen Project

Vitisgen (http://www.vitisgen.org/index.html) is a large, multi-disciplinary, collaborative project focused on decreasing the time, effort and cost involved in developing the next generation of grapes. Vitisgen incorporates cutting edge genomics technology and socioeconomic research into the traditional grape breeding and evaluation process, which will speed up the ability to identify important genes related consumer-valued traits like disease resistance, low temperature tolerance and enhanced fruit quality. Identifying these genes will help grape breeding programs from around the world to more rapidly develop new grape varieties that will appeal to a wide range of consumers, while also addressing grower and producer needs. Additionally, the scientific resources developed during the project will allow scientists and breeders to address other issues and needs that have regional significance, like salinity or drought tolerance.

Vitisgen represents a new model of scientific collaboration. The integration of the needs of multiple interests—breeders, growers, fruit processors and consumers—into a single outcome will result in novel grape varieties that are beneficial to producers, processors and consumers.

I am part of this project on the extension and outreach team (http://www.vitisgen.org/teams.html#extension).  Read more about VitisGen extension here (http://www.vitisgen.org/extension.html).  This project has tremendous potential to revolutionize grapevine breeding and help reduce the time needed to get new cultivars out to growers.  I encourage  you to take a look and feel free to write me with any feedback you have.