Graduate Thesis Or Dissertation
 

The effect of nitrogen, irrigation, and cultivation on Pinot noir juice and wine composition from the Willamette Valley, Oregon

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/6t053k65d

Descriptions

Attribute NameValues
Creator
Abstract
  • This study investigated how manipulating vineyard nitrogen status, irrigation levels and cultivation practices would effect nutrient composition, and anthocyanin and phenolic accumulation in Pinot noir juice and wine from a commercial Willamette Valley Oregon vineyard. Pinot noir fruit was sourced from a vineyard trial in the Benton Lane Vineyard, located in the Southern Willamette Valley in 1999 and 2000. Treatments were applied in a factorial design varying irrigation, cultivation, and nitrogen applications. Irrigation was applied in both years post lag phase. Tilling was carried out early spring in alternate rows to promote nitrogen utilisation and reduce water and nutrient competition from vineyard grasses. Three nitrogen treatments were applied: zero nitrogen, soil nitrogen applied early spring both years at 39.2kg N/ha as urea, foliar nitrogen applied both years at the onset of ripening, and at verasion at 2.98 kg N/ha as wettable urea. Dry treatments in 1999, and 2000 had lower yields (kg/vine), smaller berry weights, higher seed weights, and greater seed weight to berry weight ratios compared to Irrigated treatments. I hypothesised that wine made from Dry treatments would have higher anthocyanins and phenolics. Ammonia (mg N/L), nitrogen from alpha amino acids (mg N/L), and yeast assimilable nitrogen content (mg N/L) were consistently higher in Dry treatments throughout the trial. No differences in pH and titratable acidity were observed in either year between Irrigated and Dry treatments. Skin anthocyanin and total phenols were found to be higher in Dry treatment berries both years, as were wine anthocyanins, colour intensity, and hue. Analysis using HPLC of 1999 wines made from the trial indicated Dry treatments had significantly higher malvidin and polymeric anthocyanin when compared to Irrigated treatments supporting our hypothesis. Berry dehydration and concentration in Dry treatments were attributed to smaller berry weights concentrating nutrients and anthocyanins. In 1999, Tilling had lower yield (kg/vine) than No-Till treatments. A delayed effect occurred in the second year and yield was higher in Tilled treatments in 2000. In both years, Tilling treatments had higher berry weights, seed weights and greater percentage seed weight per berry compared to No-Till treatments. Total soluble solids (0Brix), ammonia, nitrogen from alpha amino acids, and yeast assimilable nitrogen were higher in Till treatments in both years. No significant differences or trends between cultivation treatments were observed for titratable acidity, pH, malic acid concentration, alcohol, anthocyanins, phenolics, colour intensity and hue in either year. Soil Nitrogen (SN) treatments in 1999 and 2000 had significantly lower yields, seed weights, and a higher percentage seed weight per berry due to small berries compared to Zero Nitrogen (ZN) and Foliar Nitrogen (FN) treatments. It was hypothesised that wines made from SN treatments would have greater colour intensity and anthocyanins than ZN and FN treatments. Ammonia levels were lower in SN treatments, however, nitrogen from alpha amino acids (NOPA) was higher in SN treatments yielding higher net yeast assimilable nitrogen content (YANC) in both years. The ZN treatments had lower juice pH, higher titratable acidity and malate concentration compared to FN and SN treatments in 1999 and 2000. No significant difference was observed in soluble solids or alcohol content in any treatment. Soil Nitrogen treatments both years had significantly higher skin anthocyanins and phenolics. Wines from SN treatments tended to have higher anthocyanins, phenolics, colour intensity and hue in both years compared to ZN and FN wines. Analysis by HPLC in 1999 indicated SN wines were significantly higher in polyphenols and polymeric anthocyanins supporting our hypothesis. These results indicate that irrigation and soil nitrogen treatments had positive effects on wine quality.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Scamax Scan+ V.1.0.32.10766 on a Scanmax 412CD by InoTec inPDF format. LuraDocument PDF Compressor V.5.8.71.50 used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details WALLKATHERINE2003.pdf 2017-08-19 Public Download