Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Investigation of fresh grapevine organs using infrared spectroscopy and chemometrics
Thesis (PhDAgric)--Stellenbosch University, 2022.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Stellenbosch : Stellenbosch University
2022
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613776324329472 |
|---|---|
| access_status_str | Open Access |
| author | Van Wyngaard, Elizma |
| author2 | Aleixandre-Tudo, Jose Luis |
| author_browse | Aleixandre-Tudo, Jose Luis Van Wyngaard, Elizma |
| author_facet | Aleixandre-Tudo, Jose Luis Van Wyngaard, Elizma |
| author_sort | Van Wyngaard, Elizma |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDAgric)--Stellenbosch University, 2022. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/126364 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:41:31.332Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/126364 Investigation of fresh grapevine organs using infrared spectroscopy and chemometrics Van Wyngaard, Elizma Aleixandre-Tudo, Jose Luis Blancquaert, Erna Nieuwoudt, Helene Stellenbosch University. Faculty of AgriSciences. Dept. of Viticulture & Oenology & Institute for Wine Biotechnology. Grapes -- Analysis Grapes -- Growth Plant phenomorphology Plant phenology -- Physiological effect Infrared spectroscopy -- Technique Chemometrics -- Data processing Plant morphology -- Measurement UCTD Thesis (PhDAgric)--Stellenbosch University, 2022. ENGLISH ABSTRACT: Innovative technologies are constantly emerging to implement precision viticulture and develop sustainable agricultural practices. Infrared spectroscopy is one such technology known for rapid sample measurement and economic viability. Infrared techniques can measure various sample formats, including fresh plant material. Infrared research on fresh grapevine organs is limited with the scope of these studies often restricted to a single organ. This study proposed the in-depth exploration of the spectral properties of multiple fresh grapevine organs, at various phenological stages, across the growing season. The organ’s spectra may provide information on chemical, physical, and morphological composition during the season. First, the study investigated differences in the spectral properties of fresh grapevine organs using infrared spectroscopy and chemometrics. Clustering analyses showed distinct differences between grapevine organs and some variation among phenological stages. Further investigation per organ exhibited evident dissimilarities between phenological stages for shoots and berries. Additionally, differences among lignification stages for shoots were found. Furthermore, the classification of the observed differences was attempted. Accurate classification per grapevine organ, lignification, and some phenological stages were reported. The application of variable selection improved these predictions, especially for organ type and lignification stage. Clustering and classification analyses supplied novel information on fresh grapevine organs during the growing season. Thereafter, the novel prediction of physical attributes in fresh grapevine organs was explored. Various chemometric methods and three infrared techniques were applied to predict berry and shoot diameter, and shoot and leaf weight. These chemometric methods included linear and non-linear regression, spectral pre-processing, and variable selection. Accurate prediction of berry diameter, and moderate to good prediction of shoot diameter were reported. The predictions of shoot and leaf weight yielded moderate to poor calibrations. Near infrared techniques performed better than mid infrared, while linear and non-linear regression methods showed similar prediction results with pre-processing and variable selection only leading to marginal differences. Physical attribute predictions supply information on grapevine growth, berry development, and yield. Lastly, a novel model optimisations strategy for viticultural and spectral data was explored. Calibrations with a small reference dataset were developed for nitrogen, carbon, and hydrogen. These calibrations were applied to predict the reference compounds in larger datasets. The larger datasets were utilised to construct global and specialised calibrations per grapevine organ, phenological stage, and lignification. Overall, the larger datasets provided improved prediction accuracy compared to the initial calibrations built with the reduced reference data. Substantial improvement in predictability was observed for specialised calibrations per organ compared to global calibrations containing all organs. Several of the calibrations per phenological stage also showed improvement, while a slight decrease in prediction accuracy was seen for others. Lignification calibrations yielded improved accuracy for unlignified predictions. Increased predictability was noted for some lignified and dormant calibrations while others showed decreased accuracy. The ability of specialised calibrations to yield more accurate results compared to global calibrations validated our hypothesis. In future viticultural, and wider agricultural, infrared applications the development of specialised calibrations should be considered. The novel contributions of this study could lead to future in-field vineyard applications. These applications could facilitate the implementation of precision viticulture and lead more sustainable farming practices. AFRIKAANSE OPSOMMING: Nuwe innoverende tegnologië ontwikkel voordurend vir die implementering van presisie wingerdbou en die ontwikkeling van volhoubare landbou praktyke. Infrarooi spektroskopie is een van hierdie tegnologië, wat bekend is vir die vinnige meet van monsters en vir ekonomiese nuttigheid. Infrarooi tegnieke kan verskeie monsterformate meet, insluitend vars plant matriaal. Infrarooi navorsing op vars wingerd organe is baie beperk en die omvang van hierdie studies sluit gereeld net ‘n enkele orgaan in. Hierdie studie stel die in-diepte verkenning van die spektrale eienskappe van verskeie vars wingerd organe voor by veskillende fenologiese stadiums tydens die groeiseisoen. Die organe se spektra kan informasie voorsien van die chemiese, fisiese, en morfologiese komposisie tydens die seisoen. Eerstens het hierdie studie die verskille in die spektrale eienskappe van die vars wingerd organe ondersoek met infrarooi spektroskopie en chemometrie. Groepering analise het pertinente verskille tussen die wingerd organe gewys, en sommige variasie tussen die fenologiese stadiums. Verdere ondersoek per orgaan het duidelike verskille tussen die fenologiese stadiums getoon vir wingerd lote en korrels. Additionele verskille tussen lignifikasie stadiums is gevind vir wingerd lote. Die klassifikasie van die waargeneemde verskille is aangepak. Akkurate klassifikasie per wingerd orgaan, lignifikasie, en sommige fenologiese stadiums is gerapporteer. Die toepassing van veranderlike seleksie het die klassifikasie verbeter, spesifiek vir orgaan tipe en lignifikasie stadium. Groepering en klassifikasie analise het nuwe informasie voorsien van vars wingerd organe gedurende die groeiseisoen. Daarna is die nuwige voorspelling van fisiese eienskappe in vars wingerd organe verken. Verkeie chemometriese metodes en drie infrarooi tegnieke is ingespan vir die voorspelling van korrel en loot deursnee, en loot en blaar gewig. Hierdie chemometriese metodes het liniêre en nie-liniêre regressie, spektrale voorverwerking, en veranderlike seleksie ingesluit. Akkurate voorspellings vir korrel deursnee en matig tot goeie voorspellings vir loot deursnee is gevind. Die voorspelling van loot en blaar gewig het matig tot swak kalibrasies opgelewer. Naby-infrarooi tegnieke het better presteer as middel infrarooi, terwyl liniêre en nie-liniêre regressie metodes soortgelyke resultate gelewer het. Spektrale voorverwerking en veranderlike seleksie het net tot marginale verskille gelei. Fisiese eienskap voorspellings voorsien informasie van wingerd groei, korrel ontwikkelling, en druiwe opbrengs. Laastens is ‘n nuwige optimiserings strategie ondersoek vir wingerkundige en spektrale data. Kalibrasies vir ‘n klein verwysingsdatastel is ontwikkel vir stikstof, koolstof, en waterstof. Hierdie kalibrasies is gebruik om die verwysings verbindings te voorspel in groter datastelle. Die groter datastelle is toe benut om globale en gespesialiseerde kalibrasies te bou per wingerd orgaan, fenologiese stadium, en lignifikasie. Oor die algemeen het die groter datastelle beter voorspellingsakkuraatheid gehad in vergelyking met die oorsproklike kalibrasies gebou met die kleiner verwysingsdatastel. Aansienlike verbeterings in voorspelling is waargeneem vir die gespesialiseerde kalibrasies per orgaan in vergelyking met die globale kalibrasies wat al die organe ingesluit het. Verskeie van die kalibrasies per fenologiese stadium het verbeteringe gewys, terwyl ander effense afnames in voorspellingsakkuraatheid getoon het. Lignifikasie kalibrasies het beter akkuraatheid opgelewer vir ongelignifiseerde voorspellings. Verhoogde voorspellings is net gesien vir sommige van die gelignifiseerde en dormante kalibrasies, terwyl ander n afname gewys het. Die vermoë van gespesialiseerde kalibrasies om meer akkurate resultate te produseer in vergelyking met globale kalibrasies valideer ons hipotese. In toekomstige wingerkunde, en wyer lanboukundige, infrarooi toepassings moet die ontwikkeling van gespesialiseerde kalibrasies oorweeg word. Die nuwige bydrae van hierdie studie kan lei tot toekomstige wingerd toepassing direk in die veld. Hierdie toepassings kan die implementering van presisie wingerdbou fasiliteer en lei tot meer volhoubare landbou praktyke. Doctoral 2022-11-17T20:05:44Z 2023-01-23T06:54:12Z 2022-11-17T20:05:44Z 2022-12 Thesis http://hdl.handle.net/10019.1/126364 en Stellenbosch University xv, 123 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Grapes -- Analysis Grapes -- Growth Plant phenomorphology Plant phenology -- Physiological effect Infrared spectroscopy -- Technique Chemometrics -- Data processing Plant morphology -- Measurement UCTD Van Wyngaard, Elizma Investigation of fresh grapevine organs using infrared spectroscopy and chemometrics |
| title | Investigation of fresh grapevine organs using infrared spectroscopy and chemometrics |
| title_full | Investigation of fresh grapevine organs using infrared spectroscopy and chemometrics |
| title_fullStr | Investigation of fresh grapevine organs using infrared spectroscopy and chemometrics |
| title_full_unstemmed | Investigation of fresh grapevine organs using infrared spectroscopy and chemometrics |
| title_short | Investigation of fresh grapevine organs using infrared spectroscopy and chemometrics |
| title_sort | investigation of fresh grapevine organs using infrared spectroscopy and chemometrics |
| topic | Grapes -- Analysis Grapes -- Growth Plant phenomorphology Plant phenology -- Physiological effect Infrared spectroscopy -- Technique Chemometrics -- Data processing Plant morphology -- Measurement UCTD |
| url | http://hdl.handle.net/10019.1/126364 |
| work_keys_str_mv | AT vanwyngaardelizma investigationoffreshgrapevineorgansusinginfraredspectroscopyandchemometrics |