The impact of grapevine red blotch virus (GRBV) on Vitis vinifera L. manifests predominantly as reductions in gas exchange, berry total soluble solids, and anthocyanins. Disease management is currently restricted by incomplete understanding of virus spread and is thus limited to vine removal. The present study investigated the potential of irrigation and cluster thinning to improve fruit quality in GRBV-infected Pinot noir vines. Two irrigation levels—grower standard and supplemental (2x grower standard)—were applied in a factorial combination with two cluster thinning levels—thinned to one cluster/shoot (at peppercorn-sized berries) and nonthinned (control)—on two different rootstocks: Riparia Gloire and 3309C. Vine growth, disease severity, and fruit composition were observed for three years to understand the potential effects of the treatments on GRBV-infected vines. Supplemental irrigation attenuated the proportion of red leaves, but thinning did not have a consistent effect. Supplemental irrigation increased yield by 16 to 23% and berry mass by 9 to 10% between rootstocks. Thinning clearly decreased yield, but it also increased berry mass by 4 to 11% between rootstocks. Supplemental irrigation increased gas exchange in 2020, yet thinning slightly reduced gas exchange. These impacts on gas exchange did not affect total soluble solids in the fruit at harvest. Increases in berry sugar content indicate that sugar import increased commensurately with berry size as a function of both increased irrigation and cluster thinning. Crop load (Ravaz index) exhibited a correlation with berry sugar for the Riparia Gloire rootstock only, suggesting that crop load adjustment has a limited impact on ripening for GRBV-infected vines. Neither irrigation nor thinning significantly impacted anthocyanin concentration, and the impact on other secondary metabolites was inconsistent. The respective increase or decrease in yield may determine whether the limited improvements of supplemental irrigation and thinning on fruit quality in GRBV-infected vines are beneficial.
{"title":"Cluster Thinning Does Not Improve Fruit Composition in Grapevine Red Blotch Virus-infected Vitis vinifera L.","authors":"Cody R. Copp, A. Kc, A. Levin","doi":"10.5344/ajev.2021.21016","DOIUrl":"https://doi.org/10.5344/ajev.2021.21016","url":null,"abstract":"The impact of grapevine red blotch virus (GRBV) on Vitis vinifera L. manifests predominantly as reductions in gas exchange, berry total soluble solids, and anthocyanins. Disease management is currently restricted by incomplete understanding of virus spread and is thus limited to vine removal. The present study investigated the potential of irrigation and cluster thinning to improve fruit quality in GRBV-infected Pinot noir vines. Two irrigation levels—grower standard and supplemental (2x grower standard)—were applied in a factorial combination with two cluster thinning levels—thinned to one cluster/shoot (at peppercorn-sized berries) and nonthinned (control)—on two different rootstocks: Riparia Gloire and 3309C. Vine growth, disease severity, and fruit composition were observed for three years to understand the potential effects of the treatments on GRBV-infected vines. Supplemental irrigation attenuated the proportion of red leaves, but thinning did not have a consistent effect. Supplemental irrigation increased yield by 16 to 23% and berry mass by 9 to 10% between rootstocks. Thinning clearly decreased yield, but it also increased berry mass by 4 to 11% between rootstocks. Supplemental irrigation increased gas exchange in 2020, yet thinning slightly reduced gas exchange. These impacts on gas exchange did not affect total soluble solids in the fruit at harvest. Increases in berry sugar content indicate that sugar import increased commensurately with berry size as a function of both increased irrigation and cluster thinning. Crop load (Ravaz index) exhibited a correlation with berry sugar for the Riparia Gloire rootstock only, suggesting that crop load adjustment has a limited impact on ripening for GRBV-infected vines. Neither irrigation nor thinning significantly impacted anthocyanin concentration, and the impact on other secondary metabolites was inconsistent. The respective increase or decrease in yield may determine whether the limited improvements of supplemental irrigation and thinning on fruit quality in GRBV-infected vines are beneficial.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"73 1","pages":"56 - 66"},"PeriodicalIF":1.9,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42127886","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}
The choice of planting density is a key decision for grapegrowers to make before vineyard establishment, with long-term implications. The field trial described here, with drip-irrigated, machine-pruned Concord juice grapes, tested the effects of two between-row distances (2.44 m and 2.74 m) and four within-row distances (0.91, 1.83, 2.74, and 3.66 m), resulting in planting densities ranging from 997 to 4485 vines/ha, on yield formation and fruit composition. Canopy size, yield components, and fruit composition were measured over six years, starting in year 3 after planting. While in the first cropping season the yield with 0.91 m and 1.83 m vine spacing (11.8 t/ha) was twice that with 2.74 m and 3.66 m (5.6 t/ha), on average over the five subsequent years, the yield of 0.91-m vines was 38% lower (18.2 t/ha) than at the other planting distances (29.2 t/ha). During the last four years, the average yield of vines planted with 2.44 m between rows was 2 t/ha greater than that at 2.74 m. The yield potential and fruit quality of closely spaced vines (0.91 m) was compromised by their vigorous growth, high canopy density, and poor microclimate, which resulted in fewer clusters/vine, fewer berries/cluster, lower cluster weights, and more bunch-stem necrosis. Leaf death in the canopy interior was associated with nutrient remobilization and high potassium and pH in the juice from 0.91-m vines. Juice total soluble solids, titratable acidity, and color remained unaffected by planting density. These results show that planting juice grapes at high density in irrigated and highly mechanized vineyards is detrimental to both cropping potential and fruit quality.
{"title":"High Planting Density Reduces Productivity and Quality of Mechanized Concord Juice Grapes","authors":"M. Keller, L. Mills","doi":"10.5344/ajev.2021.21014","DOIUrl":"https://doi.org/10.5344/ajev.2021.21014","url":null,"abstract":"The choice of planting density is a key decision for grapegrowers to make before vineyard establishment, with long-term implications. The field trial described here, with drip-irrigated, machine-pruned Concord juice grapes, tested the effects of two between-row distances (2.44 m and 2.74 m) and four within-row distances (0.91, 1.83, 2.74, and 3.66 m), resulting in planting densities ranging from 997 to 4485 vines/ha, on yield formation and fruit composition. Canopy size, yield components, and fruit composition were measured over six years, starting in year 3 after planting. While in the first cropping season the yield with 0.91 m and 1.83 m vine spacing (11.8 t/ha) was twice that with 2.74 m and 3.66 m (5.6 t/ha), on average over the five subsequent years, the yield of 0.91-m vines was 38% lower (18.2 t/ha) than at the other planting distances (29.2 t/ha). During the last four years, the average yield of vines planted with 2.44 m between rows was 2 t/ha greater than that at 2.74 m. The yield potential and fruit quality of closely spaced vines (0.91 m) was compromised by their vigorous growth, high canopy density, and poor microclimate, which resulted in fewer clusters/vine, fewer berries/cluster, lower cluster weights, and more bunch-stem necrosis. Leaf death in the canopy interior was associated with nutrient remobilization and high potassium and pH in the juice from 0.91-m vines. Juice total soluble solids, titratable acidity, and color remained unaffected by planting density. These results show that planting juice grapes at high density in irrigated and highly mechanized vineyards is detrimental to both cropping potential and fruit quality.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"358 - 370"},"PeriodicalIF":1.9,"publicationDate":"2021-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47215242","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}
C. Squeri, I. Diti, I. Rodschinka, S. Poni, P. Dosso, C. Scotti, M. Gatti
The best Lambrusco wines are often obtained by blending a representative of the Lambrusco family (i.e., Lambrusco Salamino) with a smaller fraction of Ancellotta, a teinturier variety possessing an extraordinary quality of accumulating color. Because of the economic importance of the Lambrusco business and the rising interest in precision viticulture, a two-year trial was carried out in seven vineyard plots growing both the named varieties. A RapidEye satellite image taken on 9 Aug 2018 led to vigor maps based on unfiltered normalized difference vegetation index (NDVI). In both years, ground truthing was performed on the test vines chosen within each vigor area for soil features, vegetative growth, yield, grape, and final wine composition. For data pooled over sites and years, Ancellotta showed a very clear response to NDVI-based vigor mapping, as low vigor areas always achieved improved ripening in terms of higher total soluble solids (+1.24 Brix), color and phenols (+0.36 mg/kg and +0.44 mg/kg, respectively), and lower malate (-1.79 g/L) versus high vigor. Such a behavior was shown even in those cases where NDVI of different vigor levels and pruning weight were not closely correlated and, most notably, low vigor matched with a slightly higher yield as compared to high vigor plots. Overall, the high-yielding Lambrusco Salamino was less responsive in terms of vine performance and grape composition versus intravineyard variability. This study highlights that in Ancellotta, adjusting the vine balance toward ostensible lower vigor (i.e., pruning weight ≤1 kg/m) would result in a superior choice in terms of improved ripening and wine profiles would not be detrimentally affected by the yield level which, in fact, increased in some cases.
{"title":"The High-Yielding Lambrusco (Vitis vinifera L.) Grapevine District Can Benefit from Precision Viticulture","authors":"C. Squeri, I. Diti, I. Rodschinka, S. Poni, P. Dosso, C. Scotti, M. Gatti","doi":"10.5344/ajev.2021.20060","DOIUrl":"https://doi.org/10.5344/ajev.2021.20060","url":null,"abstract":"The best Lambrusco wines are often obtained by blending a representative of the Lambrusco family (i.e., Lambrusco Salamino) with a smaller fraction of Ancellotta, a teinturier variety possessing an extraordinary quality of accumulating color. Because of the economic importance of the Lambrusco business and the rising interest in precision viticulture, a two-year trial was carried out in seven vineyard plots growing both the named varieties. A RapidEye satellite image taken on 9 Aug 2018 led to vigor maps based on unfiltered normalized difference vegetation index (NDVI). In both years, ground truthing was performed on the test vines chosen within each vigor area for soil features, vegetative growth, yield, grape, and final wine composition. For data pooled over sites and years, Ancellotta showed a very clear response to NDVI-based vigor mapping, as low vigor areas always achieved improved ripening in terms of higher total soluble solids (+1.24 Brix), color and phenols (+0.36 mg/kg and +0.44 mg/kg, respectively), and lower malate (-1.79 g/L) versus high vigor. Such a behavior was shown even in those cases where NDVI of different vigor levels and pruning weight were not closely correlated and, most notably, low vigor matched with a slightly higher yield as compared to high vigor plots. Overall, the high-yielding Lambrusco Salamino was less responsive in terms of vine performance and grape composition versus intravineyard variability. This study highlights that in Ancellotta, adjusting the vine balance toward ostensible lower vigor (i.e., pruning weight ≤1 kg/m) would result in a superior choice in terms of improved ripening and wine profiles would not be detrimentally affected by the yield level which, in fact, increased in some cases.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"267 - 278"},"PeriodicalIF":1.9,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71029516","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}
Menglong Liu, Yichao Song, Hongyong Liu, Meiling Tang, Yuxin Yao, H. Zhai, Zhen Gao, Yuan-peng Du
Insufficient sunlight during veraison to maturity of winegrapes is a primary factor that inhibits production of phenolic compounds. In this study, a novel thinning technique called cluster tip removal (CTR) was applied to inflorescences of Vitis vinifera L. Marselan grapes, and the berry composition, phenolic profiles, and antioxidant activities of berry skins and wines were determined. CTR of inflorescences reduced cluster compactness, lowered titratable acidity, and increased total soluble solids in berries. CTR also increased concentrations of total phenolics, anthocyanins, tannins, and flavonoids in the pedicel end of berry skins and enhanced concentrations of 12 phenolic compounds. It also increased the concentrations of total flavanols and anthocyanins in wines. CTR berries and wines also had increased antioxidant capacities. Finally, expression of phenolic-related genes was upregulated in the skin of CTR berries.
{"title":"Effects of Flower Cluster Tip Removal on Phenolics and Antioxidant Activity of Grape Berries and Wines","authors":"Menglong Liu, Yichao Song, Hongyong Liu, Meiling Tang, Yuxin Yao, H. Zhai, Zhen Gao, Yuan-peng Du","doi":"10.5344/ajev.2021.20072","DOIUrl":"https://doi.org/10.5344/ajev.2021.20072","url":null,"abstract":"Insufficient sunlight during veraison to maturity of winegrapes is a primary factor that inhibits production of phenolic compounds. In this study, a novel thinning technique called cluster tip removal (CTR) was applied to inflorescences of Vitis vinifera L. Marselan grapes, and the berry composition, phenolic profiles, and antioxidant activities of berry skins and wines were determined. CTR of inflorescences reduced cluster compactness, lowered titratable acidity, and increased total soluble solids in berries. CTR also increased concentrations of total phenolics, anthocyanins, tannins, and flavonoids in the pedicel end of berry skins and enhanced concentrations of 12 phenolic compounds. It also increased the concentrations of total flavanols and anthocyanins in wines. CTR berries and wines also had increased antioxidant capacities. Finally, expression of phenolic-related genes was upregulated in the skin of CTR berries.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"298 - 306"},"PeriodicalIF":1.9,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45803169","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}
C. Medina-Plaza, N. Dokoozlian, R. Ponangi, T. Blair, D. Block, A. Oberholster
The composition of skin cell wall material from Pinot noir and Cabernet Sauvignon grape berries from four different regions in California was investigated to determine relationships between cell wall composition and phenolic extractability observed under winemaking conditions. Multiple vineyards (sites) per region were studied. Cell wall composition analysis included determining total soluble sugars, proteins, noncellulosic glucose, cellulose, lignin, lipids, total polyphenolic content, soluble polysaccharides, and uronic acid, as well as isolation efficiency. Results indicated that cell wall material (CWM) composition is mainly site-specific, with some effect due to variety and little to no effect from the growing region. Grape phenolics analyzed included monomeric flavan-3-ols, anthocyanins, polymeric phenols, and polymeric pigments and could be used to distinguish between varieties. Grapes grown in the same region exhibited similar phenolic extractability, indicating a significant effect of the growing area, as well as a synergistic effect between CWM composition and grape phenolics. CWM composition analysis indicated that demethylation of pectin favored the release of phenolics, while lignin content correlated negatively with the phenolics extracted. Proteins showed a negative correlation with polymeric phenols, whereas no correlation was found with polymeric pigments. Anthocyanin extractability was highly affected by its content within grape skins, more so than other phenolics that are present in both the skins and seeds.
{"title":"Correlation between Skin Cell Wall Composition and Polyphenol Extractability of Pinot noir and Cabernet Sauvignon Grapes","authors":"C. Medina-Plaza, N. Dokoozlian, R. Ponangi, T. Blair, D. Block, A. Oberholster","doi":"10.5344/ajev.2021.20045","DOIUrl":"https://doi.org/10.5344/ajev.2021.20045","url":null,"abstract":"The composition of skin cell wall material from Pinot noir and Cabernet Sauvignon grape berries from four different regions in California was investigated to determine relationships between cell wall composition and phenolic extractability observed under winemaking conditions. Multiple vineyards (sites) per region were studied. Cell wall composition analysis included determining total soluble sugars, proteins, noncellulosic glucose, cellulose, lignin, lipids, total polyphenolic content, soluble polysaccharides, and uronic acid, as well as isolation efficiency. Results indicated that cell wall material (CWM) composition is mainly site-specific, with some effect due to variety and little to no effect from the growing region. Grape phenolics analyzed included monomeric flavan-3-ols, anthocyanins, polymeric phenols, and polymeric pigments and could be used to distinguish between varieties. Grapes grown in the same region exhibited similar phenolic extractability, indicating a significant effect of the growing area, as well as a synergistic effect between CWM composition and grape phenolics. CWM composition analysis indicated that demethylation of pectin favored the release of phenolics, while lignin content correlated negatively with the phenolics extracted. Proteins showed a negative correlation with polymeric phenols, whereas no correlation was found with polymeric pigments. Anthocyanin extractability was highly affected by its content within grape skins, more so than other phenolics that are present in both the skins and seeds.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"328 - 337"},"PeriodicalIF":1.9,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46035115","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}
The electronic configuration of oxygen (O2) does not allow it to react directly with wine reductants such as polyphenols. It relies on the catalytic intervention of iron (Fe), which redox cycles between its ferrous (Fe(II)) and ferric (Fe(III)) states. O2 oxidizes Fe(II) to Fe(III), and Fe(III) then oxidizes polyphenols. Low concentrations of copper accelerate oxidation, and nucleophiles, especially sulfite, promote polyphenol oxidation. In wine that is protected from air, Fe exists mainly as Fe(II), but the Fe(III):Fe(II) concentration ratio increases immediately on air exposure, stabilizing at varying speeds and values. The oxidation of Fe(II) in air-saturated model wine and the reduction of Fe(III) by a catechol under nitrogen in model wine were examined separately to better understand the oxidative process. The Fe(III) produced when Fe(II) reacted with O2 slows the reaction. As in wine, it was important to include sulfite to remove the intermediate hydrogen peroxide, which also oxidizes Fe(II). The reaction was pseudosecond-order in Fe(II), indicating that the transfer of both electrons to O2 is rate determining. Similarly, when Fe(III) was reduced by the catechol, the Fe(II) produced inhibited the reaction, which overall followed a pseudosecond-order rate law in Fe(III). The rate of Fe(II) oxidation was slower than the rate of Fe(III) reduction, but when the reactions occurred together, as in wine oxidation, Fe(III) and Fe(II) concentrations equilibrated such that their rates equalized. Under the conditions studied, this occurred at 32% Fe(III). This equilibrium was attained quickly, as is the case in red wine. These findings on the oxidative process should help explain the relationships between wine composition, redox state, and Fe(III):Fe(II) concentration ratios.
{"title":"Toward Understanding the Mechanism of Wine Oxidation","authors":"J. Danilewicz","doi":"10.5344/ajev.2021.21008","DOIUrl":"https://doi.org/10.5344/ajev.2021.21008","url":null,"abstract":"The electronic configuration of oxygen (O2) does not allow it to react directly with wine reductants such as polyphenols. It relies on the catalytic intervention of iron (Fe), which redox cycles between its ferrous (Fe(II)) and ferric (Fe(III)) states. O2 oxidizes Fe(II) to Fe(III), and Fe(III) then oxidizes polyphenols. Low concentrations of copper accelerate oxidation, and nucleophiles, especially sulfite, promote polyphenol oxidation. In wine that is protected from air, Fe exists mainly as Fe(II), but the Fe(III):Fe(II) concentration ratio increases immediately on air exposure, stabilizing at varying speeds and values. The oxidation of Fe(II) in air-saturated model wine and the reduction of Fe(III) by a catechol under nitrogen in model wine were examined separately to better understand the oxidative process. The Fe(III) produced when Fe(II) reacted with O2 slows the reaction. As in wine, it was important to include sulfite to remove the intermediate hydrogen peroxide, which also oxidizes Fe(II). The reaction was pseudosecond-order in Fe(II), indicating that the transfer of both electrons to O2 is rate determining. Similarly, when Fe(III) was reduced by the catechol, the Fe(II) produced inhibited the reaction, which overall followed a pseudosecond-order rate law in Fe(III). The rate of Fe(II) oxidation was slower than the rate of Fe(III) reduction, but when the reactions occurred together, as in wine oxidation, Fe(III) and Fe(II) concentrations equilibrated such that their rates equalized. Under the conditions studied, this occurred at 32% Fe(III). This equilibrium was attained quickly, as is the case in red wine. These findings on the oxidative process should help explain the relationships between wine composition, redox state, and Fe(III):Fe(II) concentration ratios.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"338 - 345"},"PeriodicalIF":1.9,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43365337","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}
Cold climate interspecific hybrid grapevines (CCIHG) selected for their superior midwinter cold hardiness have expanded grape production to cold climate regions. However, extreme weather events, such as polar vortexes and the high frequency of fall and spring freezes, often result in yield and vine losses. The main objective of this study was to evaluate changes in bud cold hardiness of five CCIHG cultivars grown in the upper Midwest to identify relative risk for freeze damage throughout the dormant period and to adapt a bud cold hardiness prediction model to CCIHG cultivars grown in cold climate regions. Bud cold hardiness was evaluated biweekly throughout the dormant period by measuring lethal temperatures for buds using differential thermal analysis (DTA). CCIHG cultivars in our study had an early acclimation response with increased levels of cold hardiness before the occurrence of freezing temperatures. Maximum levels of hardiness (-28 to -30°C) were observed both years in February; however, deeper levels of freezing stress resistance, probably attained by freeze dehydration, were not detected using DTA. CCIHG cultivars had a rapid deacclimation response that was accelerated with additional chilling accumulation during spring. The reparametrizing of a discrete-dynamic cold hardiness prediction model by expanding the range of ecodormant threshold temperatures for CCIHG resulted in predictions with an average root mean square error (RMSE) = 1.01. Although CCIHG cultivars have superior midwinter bud cold hardiness, fast deacclimation responses increase the risk of freeze damage during spring, thus this trait should be evaluated for future CCIHG cultivar release. The development of tools such as the discrete-dynamic cold hardiness prediction model for CCIHG cultivars will aid growers in decision-making to minimize damage and yield and vine losses.
{"title":"Cold Hardiness of Cold Climate Interspecific Hybrid Grapevines Grown in a Cold Climate Region","authors":"M. North, B. Workmaster, A. Atucha","doi":"10.5344/ajev.2021.21001","DOIUrl":"https://doi.org/10.5344/ajev.2021.21001","url":null,"abstract":"Cold climate interspecific hybrid grapevines (CCIHG) selected for their superior midwinter cold hardiness have expanded grape production to cold climate regions. However, extreme weather events, such as polar vortexes and the high frequency of fall and spring freezes, often result in yield and vine losses. The main objective of this study was to evaluate changes in bud cold hardiness of five CCIHG cultivars grown in the upper Midwest to identify relative risk for freeze damage throughout the dormant period and to adapt a bud cold hardiness prediction model to CCIHG cultivars grown in cold climate regions. Bud cold hardiness was evaluated biweekly throughout the dormant period by measuring lethal temperatures for buds using differential thermal analysis (DTA). CCIHG cultivars in our study had an early acclimation response with increased levels of cold hardiness before the occurrence of freezing temperatures. Maximum levels of hardiness (-28 to -30°C) were observed both years in February; however, deeper levels of freezing stress resistance, probably attained by freeze dehydration, were not detected using DTA. CCIHG cultivars had a rapid deacclimation response that was accelerated with additional chilling accumulation during spring. The reparametrizing of a discrete-dynamic cold hardiness prediction model by expanding the range of ecodormant threshold temperatures for CCIHG resulted in predictions with an average root mean square error (RMSE) = 1.01. Although CCIHG cultivars have superior midwinter bud cold hardiness, fast deacclimation responses increase the risk of freeze damage during spring, thus this trait should be evaluated for future CCIHG cultivar release. The development of tools such as the discrete-dynamic cold hardiness prediction model for CCIHG cultivars will aid growers in decision-making to minimize damage and yield and vine losses.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"318 - 327"},"PeriodicalIF":1.9,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48748481","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}
Grapevine red blotch virus (GRBV) negatively impacts vine physiology and fruit quality in Vitis vinifera L. by reducing photosynthetic rate, total soluble solids (TSS), and berry anthocyanin concentration. Currently, growers have few management strategies beyond removal of infected vines, which may be particularly costly in vineyards with high disease incidence. The present study was established in 2018 in a GRBV-infected Pinot noir vineyard in southern Oregon to investigate whether reducing vine stress with cultural practices could dampen the impact of the disease on vine physiology and fruit quality. The effects of control and supplemental levels of irrigation and fertilizer on vine growth and physiology, disease severity, and fruit composition were observed over three years. Supplemental irrigation affected vine physiology and fruit composition in 2019 and 2020, but fertilization had no significant effect over three years. Photosynthetic rate, vegetative growth, vine yield, berry weight, TSS, and titratable acidity were increased with supplemental irrigation while disease severity (symptomatic leaves per vine) was reduced. Supplemental irrigation did not have consistent effects on secondary metabolites, though an increase in anthocyanin concentration was observed in 2020 despite an increase in berry size. Irrespective of applied water amounts, maintaining a higher vine water status effectively increased photosynthesis and canopy size, which resulted in greater sugar accumulation. Ultimately, these results suggest that maintaining a high vine water status (Ψstem > -0.8 MPa) may mitigate some of the negative effects of GRBV on vine physiology and fruit composition.
{"title":"Irrigation Improves Vine Physiology and Fruit Composition in Grapevine Red Blotch Virus-Infected Vitis vinifera L.","authors":"Cody R. Copp, A. Levin","doi":"10.5344/ajev.2021.21007","DOIUrl":"https://doi.org/10.5344/ajev.2021.21007","url":null,"abstract":"Grapevine red blotch virus (GRBV) negatively impacts vine physiology and fruit quality in Vitis vinifera L. by reducing photosynthetic rate, total soluble solids (TSS), and berry anthocyanin concentration. Currently, growers have few management strategies beyond removal of infected vines, which may be particularly costly in vineyards with high disease incidence. The present study was established in 2018 in a GRBV-infected Pinot noir vineyard in southern Oregon to investigate whether reducing vine stress with cultural practices could dampen the impact of the disease on vine physiology and fruit quality. The effects of control and supplemental levels of irrigation and fertilizer on vine growth and physiology, disease severity, and fruit composition were observed over three years. Supplemental irrigation affected vine physiology and fruit composition in 2019 and 2020, but fertilization had no significant effect over three years. Photosynthetic rate, vegetative growth, vine yield, berry weight, TSS, and titratable acidity were increased with supplemental irrigation while disease severity (symptomatic leaves per vine) was reduced. Supplemental irrigation did not have consistent effects on secondary metabolites, though an increase in anthocyanin concentration was observed in 2020 despite an increase in berry size. Irrespective of applied water amounts, maintaining a higher vine water status effectively increased photosynthesis and canopy size, which resulted in greater sugar accumulation. Ultimately, these results suggest that maintaining a high vine water status (Ψstem > -0.8 MPa) may mitigate some of the negative effects of GRBV on vine physiology and fruit composition.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"307 - 317"},"PeriodicalIF":1.9,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49380801","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}
Meredith J. Persico, Donald E. Smith, M. Centinari
Spring freeze events pose a threat to vineyard productivity worldwide. We compared two methods to delay grapevine budbreak for freeze avoidance and evaluated their effects on phenology, yield components, fruit composition, and postharvest parameters, including wine chemistry, carbohydrate storage, and bud freeze tolerance. The two methods to delay budbreak were a vegetable oil-based adjuvant (Amigo) applied to dormant buds at 8% and 10% (v/v) and late pruning applied when apical buds reached approximately Eichhorn-Lorenz stage 7. Treatments were applied in 2018 and 2019 on two Vitis vinifera cultivars, Lemberger and Riesling, and compared to a control treatment with no delayed budbreak strategy. Amigo and late pruning delayed budbreak compared to control vines in both years and cultivars. The delay in budbreak varied from three to six days for Amigo 8%, five to eight days for Amigo 10%, and 10 to 11 days later for late pruning. In 2019, there was a freezing event near budbreak. Compared to control vines, late-pruned Lemberger vines had less shoot damage when measured during the growing season and greater yield at harvest. Delayed budbreak treatments did not influence wine chemistry either year or consistently affect carbohydrate storage or bud freeze tolerance in the following dormant season. However, in Riesling, late pruning reduced cluster and berry weight by up to 34 and 22%, respectively, compared to control vines. Furthermore, Amigo 10% may decrease bud survival when applied to Riesling vines. In general, late pruning delayed budbreak more effectively and mitigated freeze damage better than Amigo application without negatively affecting vine health or wine composition; however, the cultivar-dependent effect of late pruning on cluster weight is a consideration prior to adoption.
{"title":"Delaying Budbreak to Reduce Freeze Damage: Seasonal Vine Performance and Wine Composition in Two Vitis vinifera Cultivars","authors":"Meredith J. Persico, Donald E. Smith, M. Centinari","doi":"10.5344/ajev.2021.20076","DOIUrl":"https://doi.org/10.5344/ajev.2021.20076","url":null,"abstract":"Spring freeze events pose a threat to vineyard productivity worldwide. We compared two methods to delay grapevine budbreak for freeze avoidance and evaluated their effects on phenology, yield components, fruit composition, and postharvest parameters, including wine chemistry, carbohydrate storage, and bud freeze tolerance. The two methods to delay budbreak were a vegetable oil-based adjuvant (Amigo) applied to dormant buds at 8% and 10% (v/v) and late pruning applied when apical buds reached approximately Eichhorn-Lorenz stage 7. Treatments were applied in 2018 and 2019 on two Vitis vinifera cultivars, Lemberger and Riesling, and compared to a control treatment with no delayed budbreak strategy. Amigo and late pruning delayed budbreak compared to control vines in both years and cultivars. The delay in budbreak varied from three to six days for Amigo 8%, five to eight days for Amigo 10%, and 10 to 11 days later for late pruning. In 2019, there was a freezing event near budbreak. Compared to control vines, late-pruned Lemberger vines had less shoot damage when measured during the growing season and greater yield at harvest. Delayed budbreak treatments did not influence wine chemistry either year or consistently affect carbohydrate storage or bud freeze tolerance in the following dormant season. However, in Riesling, late pruning reduced cluster and berry weight by up to 34 and 22%, respectively, compared to control vines. Furthermore, Amigo 10% may decrease bud survival when applied to Riesling vines. In general, late pruning delayed budbreak more effectively and mitigated freeze damage better than Amigo application without negatively affecting vine health or wine composition; however, the cultivar-dependent effect of late pruning on cluster weight is a consideration prior to adoption.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"346 - 357"},"PeriodicalIF":1.9,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48665507","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}
Patricia López-García, D. Intrigliolo, M. A. Moreno, A. Martínez-Moreno, J. F. Ortega, E. Pérez-Álvarez, R. Ballesteros
Multispectral and conventional cameras (red, green, blue [RGB] imager) onboard unmanned aerial vehicles (UAVs) provide very high spatial, temporal, and spectral resolution data. To evaluate the capacity of these techniques to assess vineyard water status, we carried out a study in a cv. Monastrell vineyard located in southeastern Spain in 2018 and 2019. Several irrigation strategies were applied, including different water quality and quantity regimes. Flights were performed using conventional and multispectral cameras mounted on the UAV throughout the growth cycle. Several visible and multispectral vegetation indices (VIs) were determined from the images with only vegetation (without soil and shadows, among others). Stem water potential was measured by pressure chamber, and the water stress integral (Sψ) was obtained during the season. Simple linear regression models that used VIs and green cover canopy (GCC) to predict Sψ were tested. The results indicate that visible VIs best correlated with Sψ. The green leaf index (GLI), visible atmospherically resistant index (VARI), and GCC showed the best fits in 2018, with R2 = 0.8, 0.72, and 0.73, respectively. When the best model developed with the 2018 data was applied to the 2019 data set, the model fit poorly. This suggests that on-ground measurements of vine stress must be taken each growing season to redevelop a model that predicts water stress from UAV-based imaging.
{"title":"Assessment of Vineyard Water Status by Multispectral and RGB Imagery Obtained from an Unmanned Aerial Vehicle","authors":"Patricia López-García, D. Intrigliolo, M. A. Moreno, A. Martínez-Moreno, J. F. Ortega, E. Pérez-Álvarez, R. Ballesteros","doi":"10.5344/ajev.2021.20063","DOIUrl":"https://doi.org/10.5344/ajev.2021.20063","url":null,"abstract":"Multispectral and conventional cameras (red, green, blue [RGB] imager) onboard unmanned aerial vehicles (UAVs) provide very high spatial, temporal, and spectral resolution data. To evaluate the capacity of these techniques to assess vineyard water status, we carried out a study in a cv. Monastrell vineyard located in southeastern Spain in 2018 and 2019. Several irrigation strategies were applied, including different water quality and quantity regimes. Flights were performed using conventional and multispectral cameras mounted on the UAV throughout the growth cycle. Several visible and multispectral vegetation indices (VIs) were determined from the images with only vegetation (without soil and shadows, among others). Stem water potential was measured by pressure chamber, and the water stress integral (Sψ) was obtained during the season. Simple linear regression models that used VIs and green cover canopy (GCC) to predict Sψ were tested. The results indicate that visible VIs best correlated with Sψ. The green leaf index (GLI), visible atmospherically resistant index (VARI), and GCC showed the best fits in 2018, with R2 = 0.8, 0.72, and 0.73, respectively. When the best model developed with the 2018 data was applied to the 2019 data set, the model fit poorly. This suggests that on-ground measurements of vine stress must be taken each growing season to redevelop a model that predicts water stress from UAV-based imaging.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"285 - 297"},"PeriodicalIF":1.9,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42334424","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}
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