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From the Lake Erie Regional Grape Program Crop Update of 4/4/01

Cultural Practices - Dr. Terry Bates

With the Easter season and growing season upon us, I thought it would be an appropriate time review the Ten Commandments of Concord Production in Western New York. I hope you will allow me the latitude to blur the lines between church and state without offense (to church or state), for there is none intended.

Breaking the first three commandments are cardinal sins against viticulture because they have to do not with the physical management of the vineyard but with the mental understanding of viticulture. Breaking the last seven commandments represent mortal sins against viticulture because in doing so, you slowly kill the growth and production of Concord grapevines.

1. Thou shall be educated in viticulture.
   "Grape growing is a specialists' business, for the culture of the grape is unlike that of any other fruit" (U. P. Hedrick, 1924). How many times have your heard that knowledge is power. Viticulture is no exception. Knowledge of viticulture gives us the ability to make thoughtful management decisions. We may not always make the right or most profitable decision but with thoughtfulness we will make the right decision more often and make mistakes less often.
2. Thou shall not rely solely on tradition.
   "Grape-growing is not, however, an art wholly governed by rules of the past to be carried on by common laborers who use hands only, but is one in which its followers may make use of science and may put thought, skill and taste into their work" (U. P. Hedrick, 1924). Tradition is good. Tradition is important. Understanding tradition passes along the knowledge and experience of those that came before us. Understanding the science behind tradition also enables us to eliminate the poor or irrelevant practices and further develop the successful practices.
3. Thou shall work together for improvement.
   A "major hazard to New York grape growing" is "a deterioration of the present high level of respect between growers, and processors, and research, whether public or industrial" (N. J. Shaulis, 1956). As I have visited the other grape growing regions of the United States, I have observed something very unique about the NY Concord industry. We are the underdog of the grape world. Outsiders do not respect our trade because we "are an industry that grows a beast of a grape in a hostile climate that is too cold and too humid with too short of a growing season" (Anonymous West Coaster). I see it in an opposite light. The fact that we are successful in our industry shows the level of our viticulture skill, a skill that we did not develop in isolation. We, all in our own way, are trying to improve the production and quality of our industry. The fact that we have different opinions to discuss will help change and improve our current situation. However, we cannot let our difference of opinions degrade the respect between growers, processors, extension, and research and inhibit our ability to learn.
4. Thou shall focus on growing a vine that sufficiently fills the trellis with leaves before worrying about the crop.
   Vine size, vine size, vine size. I do not care if you balance prune, prune to a single bud number, or leave excessive buds and fruit thin later in the season. If you do not grow a big vine and fill the trellis with leaves you can forget about maximizing yield and quality. "If your vines have less than two pounds of cane prunings you should diagnose, or have diagnosed, the factors which cause this stunting" (N. J. Shaulis, 1956). Later research would bump this requirement up to about 0.3 pounds of dormant cane pruning per foot of canopy (that is 2.5 - 3.0 pounds on HRU at 8 x 9 spacing).
5. Thou shall not plant Concord grapevines in a swamp.
   "No cultivated grape endures a wet soil; all demand drainage. A few sorts may thrive for a time in moist, heavy land, but more often they do not live though they may linger" (U. P. Hedrick, 1924). Some rootstocks are tolerant of wet feet in the spring but none are resistant to year long wetness. Concord roots do not perform well in waterlogged situations. Drainage, either natural or provided through tile, is need for high Concord production.
6. Thou shall not starve Concord grapevines for water (or) Thou shall not let weeds thrive in the vineyard from bloom to veraison.
   Separate and combined research efforts by Shaulis, Pool, Lakso, and Dunst emphasize the need for adequate weed control, especially in the period from bloom to veraison. Concord vines need lots of water. Some researchers in Washington have estimated that a Concord vine with a full canopy on a clear sunny day will use up to one liter of water per hour per vine. We get 2 to 3 inches of rain a month during the growing season. The vines need that water not only for photosynthesis but for nutrient availability and uptake. Mulch and irrigation can be used to enhance the effects of good weed control (but not replace it).
7. Thou shall not starve Concord vines by mistreating their roots.
   Grapevine nutrition is not always easy to understand or to manage. For the most part in our soils, all of the nutrients that the vines need for adequate production is in the soil. However, the nutrients can be either unavailable because of soil pH or low soil water (or) the nutrients can be out of balance because of the addition of other fertilizers (or) the nutrients can be available but root growth and activity can be low because the vines have been overcropped or mistreated in some way. Two things a manager can work on is nutrient availability and/or stimulating root growth and activity. The amount of yearly nitrogen application, lime based vs potassium based fertilizer recommendations, soil vs petiole tests (and when to take them) are all traditional questions that we continue to challenge and understand (see #2).
8. Thou shall control crop.
   Undercropping and overcropping are equally sinful and appropriate cropping involves assessing vine health, vineyard potential, carryover effects, and current season growing conditions. Control crop through pruning, thinning, or a combination of the two. There is more literature on the subject than I can cover here.
9. Thou shall use the proper timing, material, and volume of water to environmentally control Concord pests.
   How about that for a political statement. I will defer to the pest guys on the specifics of pest control.
10. Thou shall divide the canopy only when excessive vine size can be achieved and maintained.
    GDC is a weapon that we have in our arsenal that can improve both yield and quality. The key, as in commandment number 4, is Vine Size! When excessive vine size can be ACHIEVED and MAINTAINED, then GDC is a powerful tool in taking production to the next level. GDC is more expensive, it uses more water, it requires more nutrients, and it can be inhibited by overcropping just like any other grapevine system.

Happy Easter!