TABLE 1.Yield, quality and development statistics for 10 varieties of grapes grown at Valley Road Vineyard in 2002.

Cultivar	Budburst	Bloom	Veraison	Harvest	Total # clusters	Total Wt (g)	Wt (g)/ Cluster	% of plants	Brix/ TA
Cabernet Franc	4/15	6/11	8/14	9/23	2469	173,505	70.2	88.9	5.03
Chardonnay	4/12	6/8	8/7	9/7	1642	67,394	41.0	95.6	3.12
Gewurztraminer	4/15	6/12	8/4	9/7	2452	135,248	55.2	87.8	4.15
Lemberger	4/12	6/14	8/2	10/11	1566	140,981	90.0	81.1	2.72
Pinot Blanc	4/15	6/10	8/14	9/9	1406	88,277	62.8	68.9	3.53
Pinot Gris	4/15	6/10	8/2	9/13	2165	95,452	44.1	81.1	4.76
Pinot Meunier	4/15	6/12	8/1	9/13	3475	144,451	41.6	75.6	4.26
Pinot Noir	4/15	6/10	8/9	9/9	2536	133,855	52.8	90.0	3.62
Semillon	4/15	6/11	8/7	9/4	1994	201,205	100.9	98.9	3.37
White Riesling	4/15	6/11	8/17	10/11	3030	193,804	64.0	88.9	4.17

Notes:
1) % plants refers to the % of plants (out of 90) producing grapes
2) Chardonnay yields were affected by frost at budburst resulting in unusually small and thin clusters.
3) Lemberger and White Riesling were affected by frost one week before harvest causing some fruit dehydration.
4) Chardonnay and Lemberger showed significant infection by powdery mildew. The vineyard has not been sprayed with fungicide since its beginning. Next year we will spray with sulfur.

The 2002 harvest year at the University of Nevada’s Valley Road Vineyard has been one of the most productive and highest quality to date. The figures contained herein, along with their explanations, will give an overall look at the success of our vineyard last year. One should not make too much of the yield data as our vineyard suffered in the early years from over-watering and cold damage. Winter survival was reduced as a result of over-watering. This has caused considerable variation in plant age and size throughout the vineyard, thus impacting the yield data. Some varieties suffered more than others. Since regulated-deficit irrigation has been introduced there has been a noticeable increase in survival of all varieties and consequently an increase in uniformity, but it will take several years for this variability to be overcome.

One of the most popular quantitative yardsticks to measure must or juice quality is the ratio of sugars to acids, or the soluble solids to titratable acidity ratio (Brix/TA). Years ago, Amerine and Ough at UC Davis recommended ratios between 3 and 3.5 for optimal juice. Winemakers today often go too much higher ratios to get enhanced flavor compounds in the fruit. A ratio of 3 should be considered a minimum value for optimal grapes. In 2002, all of our collected musts and juices exhibited outstanding Brix/TA ratios, and are currently undergoing further analysis to determine the effect of drought-stressed and well-watered grapes on wine quality and flavor.

FIGURE 1. The effect of regulated-deficit irrigation (DS) on the must and juice quality of ten varieties of grapes grown at the Valley Road Vineyard (2002).

A general trend between drought-stressed and well-watered grapes cannot be observed, indicating that drought-stress did not have a significant impact on the Brix/TA ratio of our grapes. Some varieties show a higher Brix/TA ratio among drought-stressed vines, while others show a lower ratio. It is likely that the surmised increase in wine quality among drought-stressed vines is not related to the Brix/TA ratio, but to some other metabolic components or flavor compounds.