Physiology and Biochemistry of Cold-hardy Table Grapevines

Grapes are grown worldwide to produce wine, grape juice and are also popular as fresh table grapes or dried raisins. Due to their nutritional value and importance in the multibillion-dollar wine industry, grapes are considered the most commercially important berry crop. Grape production has primarily concentrated on European wine grapes, Vitis vinifera, in the dry, hot Mediterranean and Central Asian climates. V. vinifera is not cold tolerant enough to endure winter temperatures below -15°C. The introduction of several interspecific hybrids (of both wine and table grape) cultivars in the 20th century and selection of a training system has helped propel the expansion of grapevine cultivation in cooler climates such as the Northeastern US and upper midwestern US states. Training and trellising systems are part of viticultural practices that influence many aspects of grapevine growth and productivity. Especially in cool climates like New Hampshire, choosing an appropriate training system will provide the grapevines with good exposure of leaves and berries to sunlight leading to fruits with improved berry composition and higher levels of sugar accumulation as well as increased concentrations of anthocyanins and phenolic compounds. However, there is limited research on the impact of training systems on cold-hardy table grapevine physiology and biochemistry. To address these knowledge gaps research was conducted at the UNH Woodman Horticultural Research Farm in Durham, NH, where cold-hardy grape varieties are growing on two different training systems. Mars and Canadice grape varieties grown on vertical shoot positioning (VSP) and Munson (M) training systems were used. Grapevine physiology and biochemistry were followed throughout three growing seasons using destructive and non-destructive methods to monitor grapevine health. Additionally, considering the current need for alternative environmentally friendly fungicides, plant material from these cold-hardy grape cultivars was tested for their putative antifungal properties. The objectives of this study were to: (1) Determine the physiological and biochemical parameters of Canadice and Mars cold-hardy grape varieties growing on vertical shoot positioning (VSP) and Munson training systems, and (2) Investigate the putative antifungal activity of field-collected grapevine leaves and cell suspension cultures obtained from Canadice and Mars grapevines against Botrytis cinerea. I hypothesized that the training system would influence the SPAD measurements, spectral indices (normalized difference vegetation index, red edge inflection point, moisture stress index, and phenology index), and gas exchange measurements (intercellular carbon dioxide concentration, stomatal conductance, net photosynthesis, transpiration rate, vapor pressure deficit, and water use efficiency) of Mars and Canadice leaves growing on two different training systems. I also hypothesized that the training system would have an effect on the amount of leaf photosynthetic pigments, leaf, juice, and skin metabolomes, titratable acidity and soluble solid contents of Canadice and Mars growing on two different training systems (Chapter 2). I hypothesized that field-collected leaves and cell suspension cultures established from Canadice and Mars grape varieties would contain compounds with antifungal activity against B. cinerea (Chapter 3). For objective 1, physiological parameters were measured with SPAD, spectral analysis, and gas exchange analysis on grapevine leaves throughout three growing seasons (2019, 2020, and 2021). Specifically, I determined the SPAD measurements, the spectral indices normalized difference vegetation index (NDVI), red edge inflection point (REIP), moisture stress index (MSI) and phenology index, and gas exchange measurements to determine intercellular carbon dioxide concentration (Ci), stomatal conductance (gs), vapor pressure deficit (VPD), net photosynthesis (A), transpiration (E), and water use efficiency (WUE). While no differences were found regarding training systems alone, there was a significant interaction of training system with time, suggesting that training system had different effects at different times. For the biochemical parameters, the same leaves that were used to perform SPAD measurements were used to analyze photosynthetic pigments and proton based nuclear magnetic resonance (1H-NMR spectroscopy)-based metabolomics. Consistent with the results of physiological parameters, no differences were found for photosynthetic pigments - chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids - between training systems, but the training system had different effects at different time points. The leaf metabolites studied using 1H-NMR spectroscopy coupled with multivariate statistical analysis did not distinguish samples based on training systems, but sample separation occurred based on phenological stages. The compounds identified showed variations between flowering, veraison, and harvest. Namely, sucrose gradually increased from flowering to harvest. Additionally, the 1H-NMR spectroscopy-based metabolome of grape juice was investigated in grape berries collected from veraison to harvest. Various kinds of metabolites were identified. Fructose, glucose, alanine, threonine, myo-Inositol, and 3-hydroxybutyrate were all shown to increase from veraison to harvest. The amount of fructose and glucose increased over time (between veraison and harvest) and are indicators of berry ripeness. Furthermore, at harvest, grape titratable acidity and total soluble solid content were determined, and berry skin composition was investigated using ultra performance liquid chromatography-mass spectrometry (UPLC-MS) analysis. Distinct sets of metabolites were identified in Mars and Canadice skin samples and were dependent on the training system. For my objective 2, I investigated the putative antifungal activity of Mars- and Canadice-derived products, specifically field-collected grapevine senescent leaves and cell suspension cultures, against B. cinerea. The aim was to gather knowledge that could lead to the development of new botanical fungicides that could be used as an alternative to synthetic fungicides for disease management in vineyards. This approach could contribute to sustainable management practices in the long term. Using grapevine debris (such as canes, wood, and leaves) from V. vinifera to suppress B. cinerea and other plant pathogens has been successfully demonstrated. However, there is limited research evaluating secondary metabolites with antifungal properties from cold-hardy grapevines. Our results show that grapevine-derived extracts have antifungal activity in vitro and in detached berry experiments when challenged with B. cinerea, but the antifungal activity was not translated to in planta experiments. The metabolic profiling of senescent leaves and cell suspension cultures of Mars and Canadice identified an array of compounds, including some reported to have antimicrobial properties. Given the list of compounds that have been identified in cold-hardy grapevine-derived products, future work should examine these unique compounds present in the senescent leaves and cell cultures under controlled experimental conditions. While our results indicated that Mars- and Canadice-derived products have antifungal activity, the materials used in this study were crude extracts. Future studies should focus on using finer grapevine-products to test the efficacy against B. cinerea, not only in vitro, but also using pilot-scale greenhouse trials, and vineyard trials

Spectral Survey of Irrigated Region Corps and Soils

The applications of remote sensing techniques to spectral surveys of irrigation, crops, and soils are reported. Topics discussed include: (1) canopy temperature as an indication of plant water stress, (2) temperature of soils and of crop canopies differing in water conditions, (3) ERTS project, (4) spectrum matching and pattern recognition, (5) photographic procedures and interpretation, (6) interaction of light with plants, and (7) plant physiological and histological factors

Image Processing for Machine Vision Applications

L'abstract è presente nell'allegato / the abstract is in the attachmen

Third Annual Earth Resources Program Review. Volume 2: Agriculture, forestry, and sensor studies

Remote sensing and data reduction techniques for Earth Resources Program applied to agriculture and forestry - conferenc

Development of antimicrobial composite materials for food packaging applications

Due to increasing environmental concerns regarding plastic waste, the development of composite film materials from biodegradable polymers and natural food additives is gaining more attention. Over the last few decades, the safety of synthetic additives that are commonly added as food additives has also been questioned because of their potential toxicity, carcinogenicity and teratogenicity effects. Natural antimicrobial agent could be a promising and versatile component in food packaging materials to improve their physiochemical, antioxidant and antimicrobial properties and hence, improve food quality and shelf life. In this study, novel chitosan/acetylated starch and polyvinyl alcohol/chitosan composite films were developed via a solution casting technique. In addition, a novel Escherichia phage, CAM-21, was isolated from a slurry lagoon at a local dairy farm before incorporating into soy protein isolate-based films. The results indicate that the chitosan/acetylated starch films incorporated with cinnamon and clove essential oils displayed enhanced light, water vapor, and oxygen barrier characteristics, as well as excellent antibacterial activity against spoilage bacteria and the pathogen, Escherichia coli O157:H7, on beef. Polyvinyl alcohol/chitosan films incorporated with aminosilane-modified bacterial nanocellulose and 4-hexylresorcinol exhibited improved mechanical, water vapor barrier, antioxidant, and antimicrobial properties against spoilage bacteria on vacuum packaged refrigerated raw beef. Also, CAM-21 has a broad host spectrum against various serotypes of Shiga toxin-producing E. coli. The growth of E. coli O157:H7 was effectively controlled in phage-treated milk, ground beef and baby spinach. Soy protein isolate films incorporated with CAM-21 showed excellent antimicrobial activity against E. coli O157:H7 in broth and refrigerated beef products. This project demonstrates the potential application of natural antimicrobial agents to produce novel composite films for antimicrobial food packaging.Includes bibliographical references

Monitoring Aspergillus Flavus Progression and Aflatoxin Accumulation in Inoculated Maize (Zea Mays L.) Hybrids

Aflatoxins are a secondary metabolite produced by the fungus Aspergillus flavus. A. flavus has been known to infect several crops including tree nuts, peanuts, rice, cotton and maize. Aflatoxins have been found to cause tumors with aflatoxin B1 being the most carcinogenic biologically produced substance known to man. Therefore, the FDA has restricted the amount of aflatoxin in maize for human consumption to 20 ppb (ng/g). An estimated $225 million are lost each year in the United States due to aflatoxin contamination in maize crops alone. Agriculture is a vital part of Mississippi’s economy, and maize is one of its largest crops. The purpose of this research is to track the correlations between aflatoxin accumulation and Aspergillus flavus fungal biomass for the first several weeks after inoculation, as well as the spreading of the fungus and the aflatoxin throughout the inoculated ear of maize. This will allow for better understanding of the pathogen-host interactions and how the fungus progresses over time. GA209 x T173 is the aflatoxin accumulation susceptible maize hybrid, GA209 x Mp313E is the susceptible and resistant hybrid, and Mp717 x Mp313E is the resistant maize hybrid to aflatoxin accumulation. These maize hybrids were each inoculated with toxin producing Aspergillus flavus NRRL 3357 and water as a control 21 days after silk maturation. Collections of the inoculated maize cobs were made 3, 7, 14, 21, 28, 35, and 60 days after inoculation. Maize samples were collected and analyzed for aflatoxin and DNA concentration. The extracted aflatoxin was analyzed using an LC/MS. The fungal biomass was determined by performing quantitative real time polymerase chain reaction (PCR). GA209xT173 and Mp717xMp313E showed no aflatoxin production two days after inoculation. The resistant maize hybrid lead in aflatoxin accumulation the last two years but had the least amount of fungal biomass for second and third years of the experiment The production of aflatoxin seems to begin decelerating after 21 days after inoculation. Resistance characteristics are more to prevent fungal infection. Fungal biomass was significantly higher in the susceptible hybrid GA209xT173 compared to the other hybrids. However, fungal spread was significantly higher in Mp313ExT173 and Mp717xMp313E

Detection, Control and Contamination of Mycotoxins

The objective of this collection is to illustrate the most recent research on the development of novel and/or rapid methods for mycotoxin determination, and to propose new strategies for monitoring and/or reducing mycotoxin contamination. Innovative sample preparation techniques or protocols and the possibility of multiclass mycotoxin detection will be very positively considered for possible inclusion in this Special Issue. Both methods based on (bio)sensors and chromatography with various detectors (including mass spectrometry) are welcome. Applications of already published methods on new matrices without any modification will not be accepted. However, extensive studies and monitoring on the spread of contamination through the food production chain could be of interest for this collection

Non-destructive evaluation of external and internal table grape quality

Thesis (PhDAgric)--Stellenbosch University, 2021.ENGLISH ABSTRACT: Determining the correct harvest maturity parameters of table grapes is an essential step before harvesting. The chemical analysis of table grapes to determine harvest and quality parameters such as total soluble solids (TSS), titratable acidity (TA) and pH, is very time-consuming, expensive, and destructive. Developing faster and more cost-effective methods to obtain the information can benefit the table grape industry by reducing losses suffered at the postharvest stage. There are multitudes of factors that can influence table grape postharvest quality leading to huge losses. These losses are exacerbated even further by the long list of postharvest external and internal defects that can occur, including browning in all its various manifestations. The application of cutting-edge technologies such as Fourier Transform Near-Infrared (FT-NIR) spectroscopy that can accurately assess the external and internal quality of fruit is, therefore, essential. This particularly concerns the identification of defects or assessment of the risks of defects that are likely to develop during post storage. The aim of this application would thus be to evaluate these new technologies to monitor table grape quality non-destructively, before, during, and/or after harvest. This study, therefore, focussed on the development and optimisation of faster, cost- effective, and fit-for-purpose methods to monitor harvest maturity and quality of table grapes in the vineyard before harvesting and during packaging and cold storage. Harvest of three different cultivars, namely, Thompson Seedless, Regal Seedless and Prime, happened over two seasons (2016 and 2017) from six different commercial vineyards. Five of these vineyards were in the Western Cape (two in the Hex River Valley, three in Wellington) and one in the Northern Cape (Kakamas), South Africa. Harvest occurred twice at each vineyard, at optimum ripeness and two weeks later (after the optimum harvest date). The incidence and intensity of browning on each berry on a bunch were evaluated for different defects and browning phenotypes. Quantitative harvest maturity and indicative quality parameters such as TSS, TA and pH, as well as the sensory-related parameters – sugar:acid ratio (TSS:TA ratio) and BrimA, were investigated by scanning whole table grape bunches contactless with Bruker’s MATRIX-F spectrometer in the laboratory. Partial Least Squares (PLS) regression was used to build prediction models for each parameter. Two different infrared spectrometers, namely the Bruker Multipurpose Analyser Fourier Transform Near-Infrared (MPA FT-NIR) and MicroNIR Pro 1700 were also used to determine TSS on whole table grape berries. The MicroNIR Pro 1700 was utilised in the vineyard and the laboratory and the MPA only in the laboratory. The same spectral dataset used to build the quantitative models was used to build classification models for two browning phenotypes, namely chocolate browning and friction browning. Partial Least Squares Discriminant Analysis (PLS-DA) and Artificial Neural Networks (ANN) were used for the classification tasks. Key results showed that the incidence and intensity of different defects and browning phenotypes such as sulphur dioxide (SO2) damage were prevalent on all three white seedless table grape cultivars. The incidences of fungal infection, sunburn and abrasion damage were high on Regal Seedless and Thompson Seedless in 2016. Contact browning, mottled browning and friction browning and bruising damage had higher incidences in 2017 than in 2016. Overall, the intensity of defects was very high in 2016 except on Regal Seedless from Hex River Valley. Prime from Kakamas and Wellington had the highest intensity of defects in 2017, which appeared on the grapes after 7 weeks of cold storage. Prediction models were successfully developed for TSS, TA, TSS:TA, pH, and BrimA minus acids on intact table grape bunches using FT-NIR spectroscopy in a contactless measurement mode, and applying spectral pre-processing techniques for regression analysis with PLS. The combination of Savitzky-Golay first derivative coupled with multiplicative scatter correction on the original spectra delivered the best models. Statistical indicators used to evaluate the models were the number of latent variables (LV) used to build the model, the prediction correlation coefficient (R2p) and root mean square error of prediction (RMSE). For the respective parameters TSS, TA, TSS:TA ratio, pH, and BrimA, the number of LV used when the models were build according to a random split of the calibration and validation set were 6, 4, 5, 5 and 10, the R2p = 0.81, 0.43, 0.66, 0.27, and 0.71, and the RMSEP = 1.30 °Brix, 1.09 g/L, 7.08, 0.14, and 1.80. When 2016 was used as the calibration set and 2017 as the validation set in model building the number of LV used were 9, 5, 5, 4 and the R2p = 0.44, 0.06, 0.17, 0.05, and 0.05 and the RMSEP = 3.22 °Brix, 2.41 g/L, 14.53, 0.21, and 8.03 for for the respective parameters. Determining TSS of whole table grape berries in the vineyard before and after harvesting using handheld and benchtop spectrometers on intact table grape berries showed that spectra taken in the laboratory with the MicroNIR were more homogenous than those taken in the vineyard with the same spectrometer, over the two years investigated. The results obtained with the MPA were not as good as those obtained with the MicroNIR in the laboratory were. The model constructed with the combined data of 2016 and 2017 taken in the laboratory with the MicroNIR had the best statistics in terms of R2p (0.74) and RPDp (1.97). The model constructed with the 2017 data obtained in the laboratory with the MicroNIR had the lowest prediction error (RMSEP = 1.13°Brix). Good models were obtained using PLS-DA and ANN to classify bunches as either clear or as having chocolate browning and friction browning based on the spectra obtained from intact table grape bunches with the MATRIX-F spectrometer. The classification error rate (CER), specificity and sensitivity were used to evaluate the models constructed using PLS-DA and the kappa score was used for ANN. The CER for chocolate browning (25%) was better than that of friction browning (46%) after Weeks 3 and 4 in cold storage for both class 0 (absence of browning) and class 1 (presence of browning). Both the specificity and sensitivity of class 0 and class 1 of friction browning were not as good as for chocolate browning. With ANN, the testing kappa score to classify table grape bunches as clear or having chocolate browning or friction browning showed that chocolate browning could be classified with the strong agreement after Weeks 3 and 4 and Weeks 5 and 6 and that friction browning could be classified with moderate agreement after three and four weeks in cold storage. Classification of chocolate browning and friction browning phenotypes was done using PLS-DA and ANN and the result showed that both types of browning can be classified with moderate agreement. The implications of the results of this study for the table grape industry are that the industry can move beyond just assessing methods and techniques in the laboratory towards implementation in the vineyard and the packhouse. Much quicker decisions regarding grape quality and destination of export can now be made using a combination of the MicroNIR handheld and MATRIX-F instruments for onsite quality measurement and the models to predict internal (e.g. TSS) and external (browning) quality attributes.AFRIKAANSE OPSOMMING: Die bepaling van die korrekte oesrypheidsparameters van tafeldruiwe is 'n noodsaaklike stap voor oes. Chemiese ontleding van tafeldruiwe om oes- en kwaliteitsparameters te bepaal, soos totale oplosbare vaste stowwe (TOVS), titreerbare suur (TS) en pH, is baie tydrowend, duur en vernietigend. Die ontwikkeling van vinniger en kostedoeltreffender maniere om die inligting te bekom, kan die tafeldruifbedryf bevoordeel deur verliese wat in die na-oesstadium gely word, te verminder. Dit sluit die menigte faktore in wat die gehalte van tafeldruiwe ná oes kan beïnvloed en tot verliese lui. Hierdie verliese word nog verder vererger deur die lang lys van verskillende na-oes-verwante gebreke wat kan voorkom, insluitend verbruining in al sy verskillende manifestasies. Die toepassing van toonaangewende tegnologieë soos Fourier-transform-naby- infrarooi (FT-NIR) spektroskopie wat die eksterne en interne kwaliteit van vrugte akkuraat kan beoordeel, is dus noodsaaklik. Dit is veral die identifisering van gebreke, of die beoordeling van die risiko's van gebreke, wat waarskynlik tydens die opberging kan ontstaan. Die doel van hierdie toepassing was dus om hierdie nuwe tegnologieë te evalueer om die kwaliteit van tafeldruiwe nie-vernietigend te monitor, voor, tydens en/of ná oes. Hierdie studie het dus gefokus op die ontwikkeling en optimalisering van vinniger, koste- effektiewe en geskikte doeleindes om oesrypheid en kwaliteit van tafeldruiwe in die wingerd te monitor voor oes en tydens verpakking en koelopberging. Druiwe-oes van drie verskillende kultivars (Thompson Seedless, Regal Seedless en Prime) het gedurende twee jare (2016 en 2017) uit ses verskillende kommersiële wingerde plaasgevind. Vyf van hierdie wingerde was in die Wes-Kaap (twee in die Hexriviervallei, drie in Wellington) en een in die Noord-Kaap (Kakamas), Suid-Afrika. Die oes het twee keer by elke wingerd plaasgevind, dit wil sê op die beste rypheid en twee weke later ná die optimale oesdatum. Die voorkoms en intensiteit van verbruining op elke korrel op 'n tros is op verskillende defekte en verbruiningsfenotipes geëvalueer. Kwantitatiewe oesrypheid en kwaliteitsindikatiewe parameters, naamlik TOVS, TS en pH, sowel as sensoriese verwante parameters suiker:suur-verhouding (TOVS:TS- verhouding) en BrimA is ondersoek deur heel tafeldruiftrosse sonder kontak met die Bruker se MATRIX-F-spektrometer in die laboratorium te skandeer. Gedeeltelike minste kwadrate (GMK) regressie is gebruik om modelle vir die parameters te bou. Twee verskillende infrarooi- spektrometers naamlik (a) die Bruker Multipurpose Analyzer Fourier Transform Near-Infrared (MPA FT-NIR) en (b) MicroNIR Pro 1700 is ook gebruik om TOVS op heel tafeldruifkorrels te bepaal. Die MicroNIR Pro 1700 is in die wingerd en in die laboratorium gebruik en die MPA slegs in die laboratorium. Met behulp van dieselfde spektrale datastel as die een wat gebruik word om die kwantitatiewe modelle op te stel, is klassifikasiemodelle vir twee verskillende verbruiningsfenotipes (sjokoladeverbruining en wrywingverbruining) gebou. Hierdie keer is gedeeltelike minste-kwadrate-diskriminant-analise (GMK-DA) en kunsmatige neurale netwerke (KNN) gebruik. Die belangrike resultate het getoon dat die voorkoms en intensiteit van verskillende defekte en verbruiningsfenotipes soos swaeldioksied (SO2)-skade op al drie wit pitlose tafeldruifkultivars voorgekom het. Die voorkoms van swaminfeksie, sonbrand en skaafskuur was hoog op Regal Seedless en Thompson Seedless in 2016. Kontak-, gevlekte- en wrywing verbruining sowel as kneusplekke het in 2017 'n hoër voorkoms as in 2016 gehad. Oor die algemeen was die intensiteit van defekte baie hoog in 2016 behalwe op Regal Seedless vanaf die Hexriviervallei. Prime van Kakamas en Wellington het in 2017 die hoogste intensiteit van gebreke gehad wat ná 7 weke se koelopberging op die druiwe verskyn het. Die suksesvolle ontwikkeling van modelle vir TOVS, TS, TOVS:TS verhouding, pH en BrimA op heel tafeldruiftrosse met behulp van FT-NIR-spektroskopie is bewys as inderdaad moontlik – veral as GMK met verskillende spektrale voorverwerkingstegnieke gepaard gaan. Statistiese aanwysers wat gebruik is om die modelle te evalueer, was die aantal latente veranderlikes (LV) wat gebruik is om die model te bou, die voorspellingskorrelasiekoëffisiënt (R2p) en wortelgemiddelde vierkante voorspellingsfout (WGVVF). Die kombinasie van die eerste afgeleide Savitzky-Golay tesame met die vermenigvuldigende verstrooiingskorreksie op die oorspronklike spektra het die beste modelle gelewer. Statistiese aanwysers wat gebruik is om die modelle te evalueer, was die aantal latente veranderlikes (LV) wat gebruik is om die model te bou, die voorspellingskorrelasiekoëffisiënt (R2p) en wortelgemiddelde vierkante voorspellingsfout (RMSE). Vir die onderskeie parameters TSS, TA, TSS: TA-verhouding, pH en BrimA, was die aantal LV wat gebruik is toe die modelle volgens 'n ewekansige verdeling van die kalibrasie- en valideringstel gebou is, 6, 4, 5, 5 en 10, die R2p = 0,81, 0,43, 0,66, 0,27 en 0,71, en die RMSEP = 1,30 ° Brix, 1,09 g / l, 7,08, 0,14 en 1,80. Toe 2016 as die kalibrasiestel gebruik is en 2017 as die validasieset in modelbou, was die aantal gebruikte LV 9, 5, 5, 4 en die R2p = 0,44, 0,06, 0,17, 0,05 en 0,05 en die RMSEP = 3,22 ° Brix, 2,41 g / l, 14,53, 0,21 en 8,03 vir die onderskeie parameters. Die bepaling van TOVS van heel tafeldruifkorrels in die wingerd voor en ná oes oor twee jaar met behulp van hand- en tafelbladspektrometers het getoon dat spektra wat in die laboratorium met die MicroNIR geneem is meer homogeen was as dié wat in die wingerd met dieselfde spektrometer geneem is. Die resultate wat met die MPA behaal is, was nie so goed soos met die MicroNIR in die laboratorium nie. Die model wat saamgestel is met die gekombineerde data van 2016 en 2017 wat in die laboratorium met die MicroNIR geneem is, het die beste statistieke gehad in terme van die R2p (0.74) en die RPDp (1.97). Die model wat opgestel is met die 2017 data wat in die laboratorium met die MicroNIR verkry is, het die laagste voorspellingsfout (RMSEP = 1.13°Brix) gehad. Goeie modelle is verkry met behulp van GMK-DA en KNN om trosse as skoon te klassifiseer, of as sjokoladeverbruining en wrywingsverbruining gebaseer op die spektra van die heel tafeldruiftrosse wat met die MATRIX-F-spektrometer geneem is. Die klassifikasiesyfer (KS), spesifisiteit en sensitiwiteit is gebruik om die modelle wat met behulp van GMK-DA saamgestel is, te evalueer en die kappa-telling is vir KNN gebruik. Die KS vir sjokoladeverbruining (25%) was beter as dié van wrywingsverbruining (46%) vir week 3 en week 4 vir beide klas 0 (afwesigheid van verbruining) en klas 1 (teenwoordigheid van verbruining). Beide die spesifisiteit en sensitiwiteit van klas 0 en klas 1 vir wrywingverbruining was nie so goed soos vir sjokoladeverbruining nie. Met KNN het die toetskappa-telling om tafeldruiftrosse as skoon of sjokoladeverbruining of wrywingsverbruining te klassifiseer, getoon dat sjokoladeverbruining tydens Week 3 en Week 4 en Week 5 en Week 6 met 'n matige ooreenstemming geklassifiseer kan word en dat wrywingsverbruining met matige ooreenstemming tydens Week 3 en Week 4 geklassifiseer kan word. Die implikasies van hierdie resultate vir die tafeldruifbedryf is van so 'n aard dat die bedryf nou verder kan gaan as om net metodes en tegnieke in die laboratorium te beoordeel, maar kan beweeg na implementering in die wingerd en die pakhuis. Die neem van baie vinniger besluite rakende die kwaliteit van die druiwe, dit wil sê in watter klas druiwe geplaas kan word en na watter uitvoermark druiwe gestuur kan word, is nou moontlik. Veel vinniger besluite rakende druiwekwaliteit en bestemming van uitvoer kan nou geneem word met behulp van 'n kombinasie van die MicroNIR-hand- en MATRIX-F-instrumente vir kwaliteitsmeting in situ en die modelle om interne (bv. TOVS) en eksterne (verbruining) kwaliteitseienskappe te voorspel.Doctora