Harper F. LaFond, D. Volenberg, J. Schoelz, D. Finke
{"title":"Identification of Potential Grapevine Red Blotch Virus Vector in Missouri Vineyards","authors":"Harper F. LaFond, D. Volenberg, J. Schoelz, D. Finke","doi":"10.5344/ajev.2022.21056","DOIUrl":"https://doi.org/10.5344/ajev.2022.21056","url":null,"abstract":"Grapevine red blotch virus (GRBV), the causal agent of grapevine red blotch disease, has been detected in vineyards across the United States and throughout Missouri. Insect transmission of GRBV in cultivated vineyards of Missouri has not been investigated previously. The objectives of this study were to characterize the potential insect vectors present in four commercial vineyards that had previously been determined to be infected with GRBV, test potential vectors caught in vineyards and surrounding habitats for the presence of GRBV with the use of PCR, and investigate the ability of candidate vectors to acquire and transmit GRBV using controlled greenhouse experiments. Of the vineyard-collected insects tested over the course of this research, one species of treehopper, Entylia carinata, tested positive for GRBV. This species and one other treehopper, Enchenopa binotata, were selected for direct transmission assays. Both species successfully acquired GRBV from infected grapevines and transmitted GRBV to confirmed GRBV-free grapevines. E. carinata has been identified as a promising economic vector after insect samples from vineyards tested positive for GRBV, and monitoring data placed this species as the second-most abundant treehopper captured in traps. We do not consider E. binotata a likely economically significant vector because our monitoring data showed that this species was rare and only found along edge habitat surrounding vineyards, never inside vineyard rows. Samples of the most abundant treehopper, Micrutalis calva, have not tested positive, but its vector status remains unresolved. Further research on rates of secondary spread and transmission by M. calva are required, but these results provide evidence that insect transmission of GRBV is feasible in the region.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"246 - 254"},"PeriodicalIF":1.9,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46897459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Sipiora, A. Cihlar, Samantha Abbate, Whitney Coker, J. Harris, W. Drayton
{"title":"Autonomous Phenological Development in Different Merlot Grapevine Shoots","authors":"M. Sipiora, A. Cihlar, Samantha Abbate, Whitney Coker, J. Harris, W. Drayton","doi":"10.5344/ajev.2022.21033","DOIUrl":"https://doi.org/10.5344/ajev.2022.21033","url":null,"abstract":"The common viticulture practice called “green thinning,” performed to improve uniformity of ripeness, is based on an underlying assumption that shoots (and their respective clusters) on the same grapevine are phenologically autonomous. There is no empirical evidence to support this assumption. The theory of phenological shoot autonomy in grapevines was tested over three seasons in three different Merlot vineyards located in Napa Valley. A trial was established comparing early pruning versus late pruning of spurs on separate vines or applied to the same vine in two forms: opposite cordons on the same vine or alternate spurs on the same vine. Phenological stages were followed on shoots from one vine per replicate for each treatment combination using an updated Eichhorn-Lorenz (E-L) scale from budbreak to end of veraison. The ordinal logistic regression analysis of the median phenological stages for all seasons revealed an effect of pruning date, but not pruning unit. Budbreak was delayed by 10 days the first season, by seven to nine days the second season, and between 10 and 13 days in 2020 with late pruning. Veraison was delayed five to eight days each season with late pruning on both separate vines and same vine treatments. The analysis of fruit composition three to five weeks after veraison was complete (E-L 41) also showed a lower Brix with late pruning on separate vines or the same vine, and that there was no interaction between pruning date and pruning unit in any vintages. Overall, the results support the phenological shoot autonomy theory in grapevines.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"236 - 245"},"PeriodicalIF":1.9,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44557003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Hesler, R. Cox, Rekha Bhandari, G. Loeb, T. Martinson, M. Fuchs
{"title":"Spatial Roguing Reduces the Incidence of Leafroll Disease and Curtails Its Spread in a Finger Lakes Cabernet franc Vineyard","authors":"S. Hesler, R. Cox, Rekha Bhandari, G. Loeb, T. Martinson, M. Fuchs","doi":"10.5344/ajev.2022.22004","DOIUrl":"https://doi.org/10.5344/ajev.2022.22004","url":null,"abstract":"Leafroll is one of the most economically important viral diseases of grapevines worldwide. Grapevine leafroll-associated virus 1 (GLRaV-1) and grapevine leafroll-associated virus 3 (GLRaV-3) are prevalent in New York vineyards in which low-density grape mealybug populations reside. A five-year experiment was performed in a commercial Cabernet franc vineyard in the Finger Lakes region of New York to test the influence of spatial roguing, i.e., the elimination of virus-infected vines and their two immediate within-row neighbors on each side, on the annual incidence of GLRaV-1 and GLRaV-3. In a second treatment, spatial roguing was combined with insecticides. Vines eliminated in both spatial roguing treatments were replaced by clean vines derived from virus-tested stocks. The objective of this study was to reduce temporal virus incidence to less than 1% over two consecutive years and limit virus spread. In both spatial roguing treatments, virus incidence was reduced from 5% in 2016 to less than 1% in 2020 to 2021. Among vines in the insecticide-free, non-rogued control treatment, virus incidence increased from 5 to 16% from 2016 to 2021. Insecticides applied in 2016 to 2021 helped significantly reduce grape mealybug populations to near zero annually, while populations in the untreated control vines were 57- to 257-fold higher during the same period. However, insecticides contributed relatively little to limit the number of newly infected vines. Together, these findings highlight the salient contribution of roguing to an overall leafroll disease management response in a vineyard with low disease incidence and low grape mealybug abundance. To our knowledge, this is the first report on the effectiveness of spatial roguing at reducing the annual incidence of leafroll disease in a vineyard.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"226 - 235"},"PeriodicalIF":1.9,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44252111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Silvana Cecilia Ledesma, M. C. Rubio, Pedro Aredes-Fernández
{"title":"New Rapid, Simple, and Cheap Methods to Determine Tyramine in Fermented Beverages and Culture Medium","authors":"Silvana Cecilia Ledesma, M. C. Rubio, Pedro Aredes-Fernández","doi":"10.5344/ajev.2022.21055","DOIUrl":"https://doi.org/10.5344/ajev.2022.21055","url":null,"abstract":"Fermented beverages are frequently contaminated with biogenic amines, produced by lactic acid bacteria that exhibit decarboxylase activity. Wine spoilage can occur when increased tyramine concentrations creates a product harmful to consumers. Determination of tyramine is important because it elevates blood pressure, which might cause a migraine attack in susceptible persons. We developed two rapid, inexpensive, and simple methods, a colorimetric technique and a thin-layer chromatography technique, to determine tyramine concentrations in culture medium and wine without complicated extraction procedures. The new colorimetric method showed high correlation between absorbance and tyramine concentrations from 1.0 to 100 mg/L in Moeller culture broth and red wine (r2 = 0.9995 and 0.9988, respectively). Thin-layer chromatography (nTLC) with a new visualization reagent also demonstrated a high correlation among tyramine concentrations between 5.0 and 100 mg/L and absorbance, with an r2 of 0.988. Both new methods showed a high correlation with high-performance liquid chromatography (colorimetric method, r2 = 0.9995; nTLC, r2 = 0.9982) and exhibited good tyramine recovery (>83%). The detection limit of the two new methods was comparable with existing analytical methods. The new assays are simple, inexpensive, and do not require any laborious pre-treatment of the samples. Both methods are suitable for routine analysis to quickly and safely monitor tyramine in a research or wine quality control laboratory. The methods were validated in various matrices: in culture media frequently used in microbiology laboratories, in common Argentine wine varietals, such as Cabernet Sauvignon and Torrontés, and in other fermented beverages, such as sparkling wine, cider, and craft beer.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"196 - 201"},"PeriodicalIF":1.9,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41850062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yibin Lan, Jiaming Wang, Emily Aubie, Marnie Crombleholme, A. Reynolds
{"title":"Effects of Frozen Materials Other Than Grapes on Red Wine Volatiles. Mitigation of Floral Taints by Yeast Strains","authors":"Yibin Lan, Jiaming Wang, Emily Aubie, Marnie Crombleholme, A. Reynolds","doi":"10.5344/ajev.2022.22005","DOIUrl":"https://doi.org/10.5344/ajev.2022.22005","url":null,"abstract":"“Floral taint”, a unique sensory defect that has been detected in red wines in North America, is caused by frozen leaves and petioles (materials other than grapes; MOG) introduced during mechanical harvest. Responsible volatiles are likely terpenes, norisoprenoids, and esters. Objectives of this study were to investigate volatile compounds that may cause floral taint and to evaluate yeast strains that could mitigate the problem for a series of different leaf- and petiole-based MOG levels. Replicate Cabernet franc fermentations (2017 to 2019) combined MOG treatments ([wt/wt]: 0, 0.5%, and 2% leaf blades, and 0, 1%, and 5% petioles) with three yeast strains (CSM, EC1118, and FX10). Increases in leaf and petiole levels resulted in primarily linear increases in many aroma compounds, particularly terpenes. Increases in leaf addition increased concentrations of nine (2017), 12 (2018), or 17 terpenes (2019). Increased petioles led to linear increases in 13 (2017), 12 (2018), or 15 terpenes (2019). Norisoprenoids and salicylates were also responsive. Yeast effects varied with leaf and petiole levels and with season. Fermentations with 2% leaves displayed yeast-related differences in nine, four, and 10 terpenes, and four, two, and nine esters in 2017, 2018, and 2019, respectively. Fermentations with 5% petioles displayed yeast-related differences in three, six, and eight terpenes, and three, two, and five esters in 2017, 2018, and 2019, respectively. Yeasts EC1118 and FX10 produced the least terpenes at all leaf and petiole levels, while CSM produced the most. Results suggest that incorporation of frozen MOG to fermentations will result in elevated concentrations of terpenes, norisoprenoids, and salicylates associated with floral taint, and that specific yeast strains may diminish this problem.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"117 - 133"},"PeriodicalIF":1.9,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44755738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chelsea A. Pardini, Ana Espínola‐Arredondo, M. Moyer
{"title":"Cooperation and Compensation to Mitigate Fungicide Resistance","authors":"Chelsea A. Pardini, Ana Espínola‐Arredondo, M. Moyer","doi":"10.5344/ajev.2022.21052","DOIUrl":"https://doi.org/10.5344/ajev.2022.21052","url":null,"abstract":"We evaluated grapegrowers’ awareness of fungicide resistance and willingness to adjust fungicide use practices to mitigate this problem in vineyards. We conducted a pilot study surveying a small group of grapegrowers in the United States to assess their knowledge about fungicide resistance and willingness to adjust fungicide use based on the effect that use had on their own farm and their neighboring farms’ profits. We found that though growers are generally willing to adjust their fungicide use practices if assisted with the mitigation of resistance, they were less willing to do so when that adjustment would negatively affect their profits. We also evaluated their willingness to adjust their fungicide use when lost profits were remediated with compensation. To understand the relationship between their willingness to change their practices with compensation and their baseline willingness to do so (without compensation), we conducted a logistic regression. Given the small sample inference, we used bootstrapped estimates and observed an increase on growers’ willingness to adjust their fungicide use when compensation was available. Our analysis underscores the importance of monetary compensation as an incentive to fight against fungicide resistance.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"190 - 195"},"PeriodicalIF":1.9,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47848791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yibin Lan, Jiaming Wang, Emily Aubie, Marnie Crombleholme, A. Reynolds
{"title":"Effects of Frozen Materials Other Than Grapes on Red Wine Aroma Compounds. Impacts of Harvest Technologies","authors":"Yibin Lan, Jiaming Wang, Emily Aubie, Marnie Crombleholme, A. Reynolds","doi":"10.5344/ajev.2022.22006","DOIUrl":"https://doi.org/10.5344/ajev.2022.22006","url":null,"abstract":"An undesirable sensory attribute (“floral taint”) has been detected in red wines in North America, caused by leaves and petioles (materials other than grapes [MOG]) introduced during mechanical harvest after killing frosts. From 2017 to 2019, several harvest strategies were evaluated on Ontario Cabernet franc: hand harvest (HH), conventional machine harvesting (MECH), Braud-New Holland Opti (OPTI), Gregoire GL8, MECH + optical sorting (MECH+OS), and MECH with preharvest leaf removal (MECH+BLR). Concentrations of 41 odor-active compounds were quantified by gas chromatography-mass spectrometry. Harvest treatment effects varied by season. In 2017, HH resulted in lowest ethyl isobutyrate (MECH+BLR), ethyl nonoate, cis-linalool oxide (plus MECH and OPTI), trans-linalool oxide (plus MECH+OS), β-citral, and cis- and trans-rose oxide (plus MECH and OPTI). Ethyl hexanoate was lowest in MECH, and MECH+BLR, isoamyl hexanoate was lowest in all treatments except HH, and α-ionone was lowest in MECH and MECH+BLR. In 2018, HH resulted in the lowest β-damascenone, ethyl salicylate (plus OPTI and Gregoire), citronellol (plus Gregoire), cis- and trans-rose oxide (plus Gregoire), and eugenol (plus Gregoire). Isobutyl acetate, isoamyl hexanoate, and nerol were additionally reduced by Gregoire, and isopropylmethoxypyrazine was reduced by all treatments except HH. In 2019, harvest strategy affected 27 of 41 compounds, including 11 esters and 12 terpenes. Treatments leading to lowest concentrations were HH (nine compounds), MECH (eight compounds), MECH+BLR (10 compounds), OPTI (21 compounds), Gregoire (10 compounds), and MECH+OS (22 compounds). Wines from fruit that had undergone a killing frost contained different concentrations of 14 and eight compounds (2018), and 17 and 13 compounds (2019) for Cabernet franc and Cabernet Sauvignon, respectively. Results suggest that specific harvest technologies can reduce MOG and associated increases in aroma compounds, although seasonal differences may occur.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"134 - 147"},"PeriodicalIF":1.9,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48989583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hannah M. Charnock, G. Cairns, G. Pickering, Belinda Kemp
{"title":"Production Method and Wine Style Influence Metal Profiles in Sparkling Wines","authors":"Hannah M. Charnock, G. Cairns, G. Pickering, Belinda Kemp","doi":"10.5344/ajev.2022.21051","DOIUrl":"https://doi.org/10.5344/ajev.2022.21051","url":null,"abstract":"The elemental composition of wine provides important information about origin, authenticity, and sensory considerations. Although various wine regions and varieties of still wines have been extensively studied, limited research has evaluated the metal profiles of sparkling wines, which can be produced via the bottle-fermented traditional method (TM) or the tank-fermented Charmat method (CM) in both rosé and non-rosé styles. In this study, 73 commercial sparkling wines from Canada’s Niagara Peninsula were analyzed by inductively coupled plasma-optical emission spectrometry and inductively coupled plasma-mass spectrometry to quantify 28 metal ions (silver [Ag], aluminum [Al], arsenic [As], boron [B], barium [Ba], beryllium [Be], calcium [Ca], cadmium [Cd], cobalt [Co], chromium [Cr], copper [Cu], iron [Fe], potassium [K], magnesium [Mg], manganese [Mn], molybdenum [Mo], sodium [Na], nickel [Ni], lead [Pb], antimony [Sb], selenium [Se], tin [Sn], strontium [Sr], titanium [Ti], thallium [Tl], uranium [U], vanadium [V], zinc [Zn]). All metal levels were below internationally regulated maximum limits. Higher mean levels of Cr, Ni, and Sr (0.021 ± 0.008 mg/L, 0.018 ± 0.004 mg/L, and 0.32 ± 0.07 mg/L, respectively) and lower mean levels of B (3.0 ± 0.6 mg/L) were identified in CM compared with TM wines. Cr and Ni are of particular interest because of their association with stainless steel contact during CM production. In addition, the results identified higher mean levels of K (613 ± 153 mg/L) and lower mean levels of Cu (0.034 ± 0.036 mg/L) in rosé wines compared with non-rosé style wines. These results represent the first investigation of metal content in Canadian sparkling wines and identify important elemental differences related to production technique that can inform future authenticity assessments.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"162 - 174"},"PeriodicalIF":1.9,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41808464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fruit Zone Shading to Control Grape Berry Temperature: A Modeling Study","authors":"M. A. Ponce de León, B. Bailey","doi":"10.5344/ajev.2022.21054","DOIUrl":"https://doi.org/10.5344/ajev.2022.21054","url":null,"abstract":"Recent increases in average air temperatures and heat wave intensity can present challenges in maintaining grape productivity and quality. As a result, growers are exploring approaches to protect berries from excessive temperatures, however, they can be costly and time-consuming to experimentally evaluate, and results may not be generalizable. In this work, we developed and evaluated a new 3-D model that can predict metrics related to berry temperature and light interception in response to varying vineyard architecture, topography, and shade cloth density. The resulting modeling tool was applied to better understand and evaluate a range of potential vineyard design and management practices for mitigation of elevated berry temperatures in vertically trained grapevines. Model validation showed close agreement between predicted and measured temperature dynamics, which responded appropriately to the application of shade cloth. In a simulation experiment, row spacing, row orientation, slope grade and aspect, and shade cloth density were varied to evaluate their effect on berry and canopy light interception, berry temperature spikes, and integrated berry heat accumulation. On flat terrain, a northeast-southwest row orientation provided the best compromise of berry light and temperature balance between opposing vine faces while avoiding excessive berry temperatures, while north-south rows provided good daily symmetry but had risk of high afternoon berry temperatures. The efficacy of shade cloth in mitigating excessive temperatures depended strongly on all variables considered. Slopes with southern or western exposure increased the imbalance in and risk of high berry temperatures, which in some cases could not be well-managed by shade cloth. Overall, the modeling tool appears capable of providing quantitative guidance for vineyard design and management where excessive berry temperatures are of concern.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"175 - 189"},"PeriodicalIF":1.9,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49622874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Sams, R. Bramley, Luis Sanchez, N. Dokoozlian, C. Ford, V. Pagay
{"title":"Remote Sensing, Yield, Physical Characteristics, and Fruit Composition Variability in Cabernet Sauvignon Vineyards","authors":"B. Sams, R. Bramley, Luis Sanchez, N. Dokoozlian, C. Ford, V. Pagay","doi":"10.5344/ajev.2021.21038","DOIUrl":"https://doi.org/10.5344/ajev.2021.21038","url":null,"abstract":"Soil texture, topographical data, fruit zone light measurements, yield components, and fruit composition data were taken from 125 locations in each of four Vitis vinifera L. cv. Cabernet Sauvignon vineyards in the Lodi region of California during the 2017, 2018, and 2019 seasons. Data were compared against three sources of normalized difference vegetation index (NDVI) with different spatial resolutions: Landsat 8 (LS8NDVI; 30 m), Sentinel-2 (S2NDVI; 10 m), and manned aircraft (at high resolution, HR) with the interrow removed (HRNDVI; 20 cm). The manned aircraft also captured canopy temperature (CT) derived from infrared (thermal) wavelengths (HRCT; 40 cm) for additional comparisons. HRNDVI was inversely related to HRCT, as well as to several chemical components of fruit composition including tannins and anthocyanins. While some constituents of fruit composition such as anthocyanins may be related to NDVI, canopy temperature, and/or indirect measurements collected in the field, results presented here suggest that yield and fruit composition have a strong seasonal response and therefore environmental conditions should be considered if more accurate predictions are desired. Furthermore, freely available public satellite data sources with mixed canopy and interrow pixels, such as Sentinel-2 and Landsat 8, provided similar information related to predicting specific fruit composition parameters compared to higher resolution imagery from contracted manned aircraft, from which the interrow signal was removed. Growers and wineries interested in predicting fruit composition that accounts for spatial variability may be able to conserve resources by using publicly available imagery sources and small numbers of targeted samples to achieve this goal.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"93 - 105"},"PeriodicalIF":1.9,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43989927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}