Project Number: 5358-21000-034-00
Project Type: Appropriated

Start Date: Nov 16, 2003
End Date: Nov 15, 2008

Objective:
Develop irrigation practices that support sustainable production of high quality wine and juice grapes. Determine effects of the variations in temperature found in the field environment on budburst, flowering, and fruit quality of grapevines. Develop and test an automated method for estimating yield in grapevines. Evaluate non-grafted wine grape varieties and clones grown in a cool, semiarid climate for horticultural characteristics, berry composition, and wine quality. 1. Establish and maintain a planting of cultivated, virus-free grape germplasm from sources worldwide for evaluating and testing in the Pacific Northwest. This planting will support objective 3. 2. Evaluate germplasm periodically to ensure that it continues to be free of viruses. 3. Evaluate interactions of biotic and abiotic environmental factors with cultural practices on the yield and fruit quality of grapevine. Biotic factors include plant diseases, such as crown gall or virus diseases.

Approach:
A number of approaches will be pursued to better understand grapevine production and fruit quality in the irrigated production areas of the Pacific Northwest. Variety and clonal differences will be assessed under deficit irrigation. Fruit quality parameters, including anthocyanins and volatiles, will be quantified by refractometer, high-performance liquid chromatography, and gas chromatography-mass spectroscopy, as appropriate. Sensory analysis will follow established protocols. Heat-balance sap flow gauges and whole-vine enclosures will be used to directly measure transpiration and photosynthesis. Growth variables will be assessed by standard metrics. A novel method of yield estimation will be developed by exploiting the mechanics of the trellis system. Formerly 5358-21000-025-00D (11/03).