Among the factors affecting the quality of wine, few
are more
important than the pruning decisions that occur in the vineyard over the winter months. Vineyard manager Norbert Fiebig can be found between the vine rows at Van Duzer 5-6 hours a day for three and one-half months where he single handedly prunes each vine on the 77-acre vineyard.
Having worked on the property for 20 years, Fiebig has developed a good instinct for pruning after observing the effect of pruning decisions on the quality of the fruit crop and the sustainable health of the vines. “I’m looking for a balanced vineyard where every vine has strong, but not excessive, growth.”
A native of Germany, Fiebig collected degrees in viticulture and enology before moving to Oregon in 1984. He admits that he may be unusual among vineyard managers in handling the primary pruning himself, but explains that, “If I make the right pruning decisions, there will be fewer problems later… with crop thinning, excessive canopy, and crop yield.”
Grapes are produced only on shoots growing from fresh, one-year-old fruiting canes. Consequently, explains Fiebig, “the cuts I make this year will affect not only this year’s crop but the following year as well.
Fiebig visually assesses each vine in determining how many canes to leave. “If the vine produced too much vigor during the last growing season, I leave 2 canes to be tied and 2 standing up.” The standing up vines are “growth diversion” canes which absorb the vine’s excess vigor during the first few months of growth and will later be trimmed away.
At the other extreme, says Fiebig, “with vines exhibiting signs of too much fruit the previous year, I leave two half-canes.” A half-cane contains 6-8 fruit buds compared to 12 on a full cane. The cutting back helps the overextended vine restart a balanced growth cycle.
Observers can see for themselves the wisdom of the pruning decisions in August. A vineyard with early-yellowing leaves indicates that vines are out of balance, struggling to both produce fruit and sustain the vine.
In February, a large crew helps Fiebig tie the canes to the trellis wires. Van Duzer typically sees bud break in mid April. In May, following one to two months of growth, the crew returns to remove the “growth diversion” canes after they have done their job of absorbing the vines’ excess energy.
Source: Van Duzer Vineyards, January 2005
