Thesis
Impacts of late-season soil and foliar nitrogen fertilizer supplements on wine grape yeast assimilable nitrogen (Yan) and canopy growth in Vitis vinifera L. Riesling
Washington State University
Master of Science (MS), Washington State University
08/2014
DOI:
https://doi.org/10.7273/000004300
Handle:
https://hdl.handle.net/2376/125295
Abstract
Nitrogen (N) application type and timing in Vitis vinifera L. wine grape production has been extensively studied in various grape growing regions and on countless cultivars. Due to the central role of N in vine growth and development, N status in the vineyard is carefully monitored and followed. Vines that are N deficient are provided with additional N to stimulate N metabolism and protein synthesis, but vines that have access to surplus N however, respond with excessive vegetative growth, which can lead to a reduction in yield, reduced fruit quality, and/or a hospitable environment for pests and diseases due to increased canopy density. Since wine grapes in central Washington are historically low in yeast assimilable nitrogen (YAN), the objective of this study was to evaluate the impact of supplemental post-véraison nitrogen (N) applications of organic or conventional sourced fertilizer, via soil and foliar, on irrigated 'Riesling' wine grape. In 2011 and 2012 N applications were made by either soil (simulated drip) or foliarly at the rates of 0, 17, or 34 kg/ha N in a commercial vineyard. Fruit was harvested within 2 days of commercial harvest from each plot and quality measurements taken included: yield, oBrix, TA, pH, average cluster weight, and cluster count. In addition, a subsample of fruit was collected for YAN and aromatic compound analysis. Small lot wines were made and fermentation rate was monitored. Soil NO3-N and tissue total N concentrations resulted in no evidence in treatment effects, but possible climatic effects between years. No indication of significant differences in canopy vigor resulting from N fertilizer applications could be found in 2011 or 2012, but many differences were found between years, which are possibly related to climatic differences. Results from 2011 indicate that foliar N applications and organic soil applied N, at 34 kg/ha N rate, increased YAN, but this did not hold true for 2012. Overall, differences between years are being attributed to climatic differences, and not from treatment effects.
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Details
- Title
- Impacts of late-season soil and foliar nitrogen fertilizer supplements on wine grape yeast assimilable nitrogen (Yan) and canopy growth in Vitis vinifera L. Riesling
- Creators
- Margaret McCoy
- Contributors
- Joan R Davenport (Advisor) - Washington State University, Crop and Soil Sciences, Department of
- Awarding Institution
- Washington State University
- Academic Unit
- Crop and Soil Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Identifiers
- 99900896400201842
- Language
- English
- Resource Type
- Thesis