The Effect of Vine Spacing at Oakville on Yields, Fruit Composition, and Wine Quality

¹ Department of Viticulture and Enology University of California, Davis

A spacing trial with White Riesling and Cabernet Sauvignon failed to produce evidence to support the continued close spacing of vines. Although a higher yield per unit area during the first several crops might be anticipated, both on a theoretical and physiological basis, this did not materialize. On the basis of the yields per unit of land area alone, there was no significant difference between the spacings. The same has been true of the compositional balance of the fruit and the quality scores of the subsequent wines.

The above influence of spacing on individual vine yields, and this in turn on the number of vines required to produce a ton of grapes, is of tremendous significance. The capital outlay in the planting, staking, and training of a vineyard is directly proportional to the number of vines planted per unit area. Similarly, all future operations of the vineyard are the more favorable economically as the number of vines are reduced, as long as the reduction does not diminish yields or necessitate more costly supports.

On the basis of these findings, the planting distances for this area that provide ample space for modern cultural implements and harvesting equipment would be the 12-foot rows. Within the rows, the 6- and 8-foot spacings have produced vines capable of bearing large crops. The 6 x 12 foot spacing would be adapted for vines of moderate vigor, and the 8 x 12 foot for vines of great vigor. Wider spacing would likely be beset with problems in pruning in the early life of the vineyard, and with more expense in trellises to support the large amount of bearing wood that is necessary to take care of the capacity for production of very widely spaced vines.