Thesis
Berry shrivel disorder in Vitis vinifera wine grapes
Washington State University
Master of Science (MS), Washington State University
2012
Handle:
https://hdl.handle.net/2376/102148
Abstract
Berry Shrivel (BS) is a ripening disorder in Vitis vinifera wine grapes that imparts negative quality attributes to berries, such as low pH, low sugar content, poor color and reduced yield. BS has no known causal agent, be it physiological stress or pathogen. This research attempted to find ways of inducing or mitigating/preventing BS, track the onset and progression of related senescence within rachis and berry tissues and further identify compositional irregularities associated with BS. Induction was attempted through mechanical and chemical manipulation of the rachis vasculature, although to no avail. Specifically, mechanical removal of rachis phloem did not induce similar symptoms as BS, which may prove a previously held theory of rachis phloem senescence being the cause of BS symptoms, incorrect. Cold nights and magnesium deficiency were also utilized as induction treatments without success. Vineyard yield, across years, was associated the proportion of BS-afflicted clusters in a vineyard. Mesocarp senescence was associated with visual shriveling and it mesocarp viability decreased before visual symptoms or noticeable changes in berry firmness occurred. Mesocarp senescence began between the seeds and the receptacle-berry junction (RBJ), closest to the seeds. The progression of the senescence was similar to the extent of visual shriveling and occurred in a basipetal fashion, towards the RBJ. Compositionally, the glucose:fructose ratio was significantly lower in BS berries and the extent of visual and compositional symptom development seemed to be more acute in the distal berries of BS-afflicted rachises. Distal berries of both BS and normally developing clusters contained significantly higher amounts of tartaric acid. An unexpected observation was that periderm development on the rachis peduncle may be related to natural girdling of rachises, late in the season.
Metrics
6 File views/ downloads
14 Record Views
Details
- Title
- Berry shrivel disorder in Vitis vinifera wine grapes
- Creators
- Richard Thorval Hoff
- Contributors
- Markus Keller (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Horticulture, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525158001842
- Language
- English
- Resource Type
- Thesis