Graduate Thesis Or Dissertation
 

Effects of Vineyard Managements on Grape and Wine Quality in Response to Grapevine Red Blotch Disease

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/5q47rx17j

Descriptions

Attribute NameValues
Creator
Abstract
  • Grapevine red blotch virus (GRBV) is a single-stranded DNA virus that causes grapevine red blotch disease (GRBD). Symptoms of GRBD include red discoloring of leaf margins and red veins on the underside of the leaves. GRBD affects the plant's metabolism and photosynthetic pathways, and disrupts carbon translocation and chlorophyll concentrations. As a result, vegetative growth is reduced, which causes decreased berry production and delays berry ripening. Both grape berry composition and resulting wine quality can be affected by GRBD. Significant loss in phenolic compounds, such as the pigment anthocyanin, has been reported in GRBD-affected grapes. Final wines from GRBD crops have been reported to have altered volatile aroma profiles, specifically decreased terpene concentrations. These effects can cost the wine industry thousands of dollars per hectare of infected vineyards. Three vineyard management practices were investigated in this project in an attempt to mitigate the effects of GRBD on Oregon Pinot noir grape and wine quality. The first viticulture technique investigated was the exogenous application of abscisic acid (ABA) to the cluster zone of GRBV-affected vines. ABA is an endogenous phytohormone involved in berry development known to increase grape phenolic levels in healthy plants. It was hypothesized that exogenous application of ABA could assist the infected plants in producing normal levels of phenolic compounds important for wine color, astringency, and bitterness. Over the two-year study, no significant increase in wine phenolic content was observed for ABA treated groups. The effects of ABA treatment on the volatile aroma profiles of GRBD-affected wines were inconsistent between the two growing seasons. From the two years' data, it was concluded that ABA was ineffective at mitigating the negative impacts of GRBD on Pinot noir wine composition. The second field treatment investigated grapevine cluster zone leaf removal on GRBD-affected wine. Basal cluster zone leaf removal is a common viticultural technique used in the vineyard to improve berry cluster microclimate and decrease microbial and fungal disease pressure. In this study, the timing and intensity of leaf removal were investigated for its potential to mitigate the negative impact of GRBD. Early leaf removal increased total phenolic content, phenolic acids, and flavan-3-ols in GRBD-affected wines compared to industry standard practices used as a control. The concentration of C13-norisoprenoids in GRBD wines was increased by early leaf removal treatment. The last vineyard management technique investigated in this project was deficit irrigation. Deficit irrigation regimes in vineyards are reported to increase anthocyanin concentrations in grape berries during ripening and wine volatile compounds. In this study, it was determined that irrigation treatments did not increase anthocyanin concentrations to normal levels in GRBD symptomatic grapevines. No significant difference was observed between deficit irrigated GRBD-affected and healthy control grapevines in total phenolic content. Some differences were observed in volatile aroma compounds for the irrigation treatments, although no pattern was present when vintages were compared. Further investigations are needed to confirm any trends in the impacts of deficit irrigation on GRBD in Pinot noir grapevines, and make conclusions on the efficacy of the viticulture practice for the management of the disease. The final study aimed to develop a sensitive analytical method based on head space thin-film solid phase microextraction (HS TF-SPME)-GC-MS for quantifying volatile compounds in wine matrices. Thin-film SPME has a larger surface area than SPME fibers and stir bar sorptive extraction (SBSE) twisters. Additionally, thin films can be constructed with several different polymers, which can preferentially extract compounds of varying polarities. Due to the larger sorbent area and selectivity of extraction polarities, TF-SPME has an advantage over SPME and SBSE techniques. In this study, the efficiency of different thin-film materials was investigated and compared to SBSE for analysis of wine volatile aroma compounds. It was found that the hydrophilic lipophilic balanced-polydimethylsiloxane (HLB/PDMS) had the highest extraction efficiency compared to other thin-film materials and SBSE. In wine samples, HLB/PDMS thin film demonstrated high sensitivity (LOD < 1 µg/L) for the majority of compounds, reproducibility (RSD < 25%), and spike recoveries (> 80%) for all major wine volatile aroma compounds.
License
Resource Type
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Rights Statement
Publisher
Peer Reviewed
Language
Embargo reason
  • Pending Publication
Embargo date range
  • 2022-08-31 to 2023-03-29

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details LingHuang2022.pdf 2022-08-31 Public Download