Determining the Impacts of Dormant Pruning Methods and Nitrogen Fertilization on Pinot Noir Bud Fruitfulness and Yield

View the project final report

Commodities

• Fruits: grapes

Practices

• Crop Production: fertilizers, nutrient management, dormant pruning
• Education and Training: extension, on-farm/ranch research

Vineyard sustainability requires attention to cultural practices and the labor to implement them in order to remain economically viable. Crop yield and quality are also major determinants of economic viability and need to be evaluated in sustainable vineyard systems. Currently grape growers in Oregon are faced with narrow profit margins as the cost to produce wine grapes is high due to 1) low yields and 2) significant manual labor required to implement cultural practices in the small family vineyards in the state. We explored vineyard management practices that had potential to boost yield and/or improve manual labor efficiency in Oregon vineyards. Two field experiments separately evaluated dormant pruning practices and nitrogen fertilization.

Many Oregon vineyards are cane pruned rather than spur pruned, as yield is thought to be reduced due to low fruitfulness of basal buds left during spur pruning. However, spur pruning is of interest to growers since it can significantly reduce manual labor hours per acre during pruning and can be mechanized for further cost savings. In terms of nitrogen fertilization, it is often avoided in vineyards to prevent excess vine growth which can cause reduced wine quality, but vines are often N-deficient and lead to other wine quality issues such as low N in fruit and sometimes low yield. In order to help develop management guidelines for growers, we studied the impacts of pruning practices and nitrogen fertilization on Pinot noir bud fruitfulness, a component of yield. This research will be used to develop guidelines for growers in the region to produce more consistent yields over time while also fine-tuning practices that may effectively manage nutrient and labor inputs.

Objective 1: Determine how yield potential and final harvest yields are affected by cane and spur pruning.

Sub Objective 1: Obtain labor efficiency data from collaborating grower to determine the differences in observation between the two pruning methods. 

Objective 2: Determine how nitrogen fertilization of an N-deficient vineyard impacts yield potential (fruitfulness and fruit set) and final harvest yields.