A. Bellincontro, Matteo Pollon, S. Río Segade, L. Rolle, F. Mencarelli
Twenty-four sweet Passito wines from Italy were analyzed through gas chromatography-mass spectrometry. Apart from the vinification process, which was unknown, the Passito wines differed in the water loss technique used, the grape variety, and the latitude/orography of provenance. Two volatile organic compound markers, ethyl acetate and furfural, were identified, characterizing wines produced with the technique of Vin Santo, wines from sun drying, and wines from late harvest. These compounds were found at low concentrations in wines produced with grapes dehydrated in “fruttaio” (closed facility), under controlled or uncontrolled conditions. Wines from Muscat varieties had more esters and terpenes, but the wines produced from grapes dehydrated in fruttaio in North Italy, particularly those grown on high mountains, had more than Muscat wines produced in South Italy or using sun drying. Primary and secondary aroma compounds are reported for each wine. A controlled environment during dehydration, preferably at low temperature, better preserves the aroma of grapes for wine production.
{"title":"Volatile Organic Compounds in Sweet Passito Wines as Markers of Grape Dehydration/Withering/Drying Process","authors":"A. Bellincontro, Matteo Pollon, S. Río Segade, L. Rolle, F. Mencarelli","doi":"10.5344/ajev.2020.20034","DOIUrl":"https://doi.org/10.5344/ajev.2020.20034","url":null,"abstract":"Twenty-four sweet Passito wines from Italy were analyzed through gas chromatography-mass spectrometry. Apart from the vinification process, which was unknown, the Passito wines differed in the water loss technique used, the grape variety, and the latitude/orography of provenance. Two volatile organic compound markers, ethyl acetate and furfural, were identified, characterizing wines produced with the technique of Vin Santo, wines from sun drying, and wines from late harvest. These compounds were found at low concentrations in wines produced with grapes dehydrated in “fruttaio” (closed facility), under controlled or uncontrolled conditions. Wines from Muscat varieties had more esters and terpenes, but the wines produced from grapes dehydrated in fruttaio in North Italy, particularly those grown on high mountains, had more than Muscat wines produced in South Italy or using sun drying. Primary and secondary aroma compounds are reported for each wine. A controlled environment during dehydration, preferably at low temperature, better preserves the aroma of grapes for wine production.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"152 - 163"},"PeriodicalIF":1.9,"publicationDate":"2020-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41949561","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}
In Washington, most winegrapes are own-rooted Vitis vinifera, which is susceptible to the plant-parasitic nematodes Meloidogyne hapla and Xiphinema americanum. Using resistant rootstocks to manage nematodes has not been evaluated in Washington vineyards. A long-term vineyard trial was established to evaluate the effects of soil fumigation and rootstock genotype on M. hapla and X. americanum population dynamics and vine growth during vineyard establishment (first three years) in a replant scenario. Vines in an existing V. vinifera Chardonnay vineyard were first treated with foliar glyphosate in fall 2014. Randomized areas within the vineyard were then either fumigated or not with drip-applied metam sodium. Following fumigation, vines were removed. In spring 2015, the vineyard was replanted to Chardonnay on the following rootstocks: 1103 Paulsen, 101-14 Millardet et de Grasset, Teleki 5C, and Harmony. Self-grafted and own-rooted Chardonnay were included. Fumigation reduced M. hapla soil second-stage juvenile (J2) population densities on own-rooted and self-grafted vines for only the first year postfumigation. One year postfumigation, the self-grafted and own-rooted vines had higher population densities of M. hapla J2 than rootstocks. All rootstocks supported measurable densities of M. hapla J2 but were poor hosts relative to V. vinifera. Fumigation effectively reduced population densities of X. americanum for up to 3.5 years. Fumigation also reduced early establishment pruning weights. Vines grown in fumigated areas had lower pruning weights through year 2, but rootstock was the bigger influence on pruning weights by year 3. This trial demonstrates that rootstocks have a more sustained impact on nematode reestablishment and subsequent vine health in a vineyard replant scenario than that of preplant fumigation.
在华盛顿，大多数酿酒葡萄都是自根葡萄，容易受到植物寄生线虫单倍根结线虫和美洲细齿线虫的影响。华盛顿葡萄园尚未对使用抗性砧木管理线虫进行评估。建立了一项长期的葡萄园试验，以评估土壤熏蒸和砧木基因型在重新种植的情况下，在葡萄园建立期间（前三年）对M.hapla和X.americanum种群动态和葡萄生长的影响。2014年秋季，一个现有的霞多丽葡萄园中的葡萄首次用叶面草甘膦处理。然后，葡萄园内的随机区域要么进行熏蒸，要么不进行滴涂超美钠的熏蒸。熏蒸后，葡萄藤被移走。2015年春季，葡萄园在以下砧木上重新种植霞多丽：1103 Paulsen、101-14 Millardet de Grasset、Teleki 5C和Harmony。包括自嫁接和自生根霞多丽。熏蒸仅在熏蒸后的第一年内降低了自根和自嫁接葡萄藤上的M.hapla土壤第二阶段幼树（J2）种群密度。熏蒸一年后，自嫁接和自根葡萄藤的M.hapla J2种群密度高于砧木。所有砧木都支持可测量的M.hapla J2密度，但相对于葡萄来说是较差的寄主。熏蒸有效地降低了美洲X.的种群密度长达3.5年。熏蒸还降低了早期设施的修剪重量。在熏蒸地区生长的葡萄在第二年的修剪重量较低，但在第三年，砧木对修剪重量的影响更大。这项试验表明，在葡萄园重新种植的情况下，砧木对线虫重建和随后的葡萄藤健康的影响比种植前熏蒸更持久。
{"title":"Field Performance of Winegrape Rootstocks and Fumigation during Establishment of a Chardonnay Vineyard in Washington","authors":"Katherine E East, I. Zasada, J. Tarara, M. Moyer","doi":"10.5344/ajev.2020.20023","DOIUrl":"https://doi.org/10.5344/ajev.2020.20023","url":null,"abstract":"In Washington, most winegrapes are own-rooted Vitis vinifera, which is susceptible to the plant-parasitic nematodes Meloidogyne hapla and Xiphinema americanum. Using resistant rootstocks to manage nematodes has not been evaluated in Washington vineyards. A long-term vineyard trial was established to evaluate the effects of soil fumigation and rootstock genotype on M. hapla and X. americanum population dynamics and vine growth during vineyard establishment (first three years) in a replant scenario. Vines in an existing V. vinifera Chardonnay vineyard were first treated with foliar glyphosate in fall 2014. Randomized areas within the vineyard were then either fumigated or not with drip-applied metam sodium. Following fumigation, vines were removed. In spring 2015, the vineyard was replanted to Chardonnay on the following rootstocks: 1103 Paulsen, 101-14 Millardet et de Grasset, Teleki 5C, and Harmony. Self-grafted and own-rooted Chardonnay were included. Fumigation reduced M. hapla soil second-stage juvenile (J2) population densities on own-rooted and self-grafted vines for only the first year postfumigation. One year postfumigation, the self-grafted and own-rooted vines had higher population densities of M. hapla J2 than rootstocks. All rootstocks supported measurable densities of M. hapla J2 but were poor hosts relative to V. vinifera. Fumigation effectively reduced population densities of X. americanum for up to 3.5 years. Fumigation also reduced early establishment pruning weights. Vines grown in fumigated areas had lower pruning weights through year 2, but rootstock was the bigger influence on pruning weights by year 3. This trial demonstrates that rootstocks have a more sustained impact on nematode reestablishment and subsequent vine health in a vineyard replant scenario than that of preplant fumigation.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"113 - 125"},"PeriodicalIF":1.9,"publicationDate":"2020-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42640509","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. Al Rwahnih, A. Diaz-Lara, K. Arnold, M. Cooper, Rhonda J. Smith, G. Zhuang, M. Battany, L. Bettiga, A. Rowhani, D. Golino
Grapevine Pinot gris virus (GPGV) was discovered in 2012 by high throughput sequencing (HTS) analysis of Pinot gris vineyards in Italy. GPGV is often symptomless but has also been associated with chlorotic mottling and leaf deformation. In 2015, this new member of the genus Trichovirus was first reported in the United States, in California. To assess the incidence of GPGV throughout grapegrowing regions in California, we tested multiple vineyards using real-time quantitative reverse transcription PCR. HTS and phylogenetics were used to evaluate the genetic diversity of GPGV strains recovered. GPGV was detected in 170 out of 716 (23%) grapevine samples, including white and red grape varieties, from several commercial vineyards and one nursery increase block. Moreover, GPGV was identified in three different counties (Yolo, Solano, and Napa) situated in northern California. In the case of Napa County, a widespread distribution of GPGV was determined. During the survey, symptomatic and asymptomatic plants tested positive for GPGV; however, characterized isolates shared close homology (>97% identity) with asymptomatic reference isolates, which was confirmed by phylogenetics. HTS revealed that GPGV-positive grapevines were also infected with other viruses and viroids. Finally, the relationship between GPGV infection and symptom expression is discussed.
{"title":"Incidence and Genetic Diversity of Grapevine Pinot gris Virus in California","authors":"M. Al Rwahnih, A. Diaz-Lara, K. Arnold, M. Cooper, Rhonda J. Smith, G. Zhuang, M. Battany, L. Bettiga, A. Rowhani, D. Golino","doi":"10.5344/ajev.2020.20044","DOIUrl":"https://doi.org/10.5344/ajev.2020.20044","url":null,"abstract":"Grapevine Pinot gris virus (GPGV) was discovered in 2012 by high throughput sequencing (HTS) analysis of Pinot gris vineyards in Italy. GPGV is often symptomless but has also been associated with chlorotic mottling and leaf deformation. In 2015, this new member of the genus Trichovirus was first reported in the United States, in California. To assess the incidence of GPGV throughout grapegrowing regions in California, we tested multiple vineyards using real-time quantitative reverse transcription PCR. HTS and phylogenetics were used to evaluate the genetic diversity of GPGV strains recovered. GPGV was detected in 170 out of 716 (23%) grapevine samples, including white and red grape varieties, from several commercial vineyards and one nursery increase block. Moreover, GPGV was identified in three different counties (Yolo, Solano, and Napa) situated in northern California. In the case of Napa County, a widespread distribution of GPGV was determined. During the survey, symptomatic and asymptomatic plants tested positive for GPGV; however, characterized isolates shared close homology (>97% identity) with asymptomatic reference isolates, which was confirmed by phylogenetics. HTS revealed that GPGV-positive grapevines were also infected with other viruses and viroids. Finally, the relationship between GPGV infection and symptom expression is discussed.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"164 - 169"},"PeriodicalIF":1.9,"publicationDate":"2020-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49128503","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}
J. Schoelz, D. Volenberg, M. Adhab, Zhiwei Fang, V. Klassen, C. Spinka, M. Al Rwahnih
In 2017 a survey was initiated of vineyards throughout Missouri for the presence of 19 different grapevine viruses. A total of 400 samples were collected from 25 grape cultivars, with a sample consisting of 16 petioles (four petioles from four different vines). Sampling within vineyard blocks was random, without regard to the presence or absence of symptoms. After nucleic acids were extracted from petiole samples, nucleic acid samples were analyzed using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) to detect viral RNA/DNA. At least one virus was detected in 90% of the samples. The most common virus detected in the survey was grapevine rupestris stem pitting-associated virus, which was found in 59% of the samples, followed by grapevine leafroll-associated virus 3 (53%), grapevine red blotch virus (35%), grapevine virus E (31%), grapevine leafroll-associated virus 2 (19%), grapevine virus B (17%), grapevine fleck virus (13.5%), grapevine leafroll-associated virus-2 Redglobe (9%), grapevine vein clearing virus (8%), grapevine virus A (0.5%), and grapevine leafroll-associated virus 4 strain 5 (0.2%). Two or more viruses were detected in ~65% of the samples, with an upper limit of seven viruses detected in one sample. An analysis of the survey results indicated that each grapevine cultivar appears to be infected by specific virus combinations that are, for the most part, unique to that cultivar.
{"title":"A Survey of Viruses Found in Grapevine Cultivars Grown in Missouri","authors":"J. Schoelz, D. Volenberg, M. Adhab, Zhiwei Fang, V. Klassen, C. Spinka, M. Al Rwahnih","doi":"10.5344/ajev.2020.20043","DOIUrl":"https://doi.org/10.5344/ajev.2020.20043","url":null,"abstract":"In 2017 a survey was initiated of vineyards throughout Missouri for the presence of 19 different grapevine viruses. A total of 400 samples were collected from 25 grape cultivars, with a sample consisting of 16 petioles (four petioles from four different vines). Sampling within vineyard blocks was random, without regard to the presence or absence of symptoms. After nucleic acids were extracted from petiole samples, nucleic acid samples were analyzed using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) to detect viral RNA/DNA. At least one virus was detected in 90% of the samples. The most common virus detected in the survey was grapevine rupestris stem pitting-associated virus, which was found in 59% of the samples, followed by grapevine leafroll-associated virus 3 (53%), grapevine red blotch virus (35%), grapevine virus E (31%), grapevine leafroll-associated virus 2 (19%), grapevine virus B (17%), grapevine fleck virus (13.5%), grapevine leafroll-associated virus-2 Redglobe (9%), grapevine vein clearing virus (8%), grapevine virus A (0.5%), and grapevine leafroll-associated virus 4 strain 5 (0.2%). Two or more viruses were detected in ~65% of the samples, with an upper limit of seven viruses detected in one sample. An analysis of the survey results indicated that each grapevine cultivar appears to be infected by specific virus combinations that are, for the most part, unique to that cultivar.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"73 - 84"},"PeriodicalIF":1.9,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48821082","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 purpose of this study was to empirically estimate machine and labor costs for mechanization of viticultural processes and to assess the relative effect of mechanization options on viticultural costs. By identifying three external factors that determined the degree of optimal mechanization of three major viticultural processes, we developed a systematic typology of 12 unique vineyard types. To estimate the effects of the factors and processes on production costs, we analyzed the variance of more than 3400 single working time records of five German wine estates across three years with fixed and random effects. Mechanization of general viticultural processes, harvesting, and pruning strongly affected viticultural costs. Minimal pruning provided a cost savings potential of 58% for vineyards that permitted mechanized harvesting. Very steep slopes suffered significant cost disadvantages of up to 164% that could only partially be compensated by mechanization. We identified opportunities for wine producers to improve their economic profitability by increasing viticultural mechanization. The methodological framework developed can be applied to other wine regions with different cost settings and the analysis of big data sets from digitalization of viticulture. The results can aid wine producers and policymakers to choose cost-efficient viticultural systems and provide benchmarks to compare labor intensity.
{"title":"Effects of Viticultural Mechanization on Working Time Requirements and Production Costs","authors":"L. Strub, A. Kurth, S. Loose","doi":"10.5344/ajev.2020.20027","DOIUrl":"https://doi.org/10.5344/ajev.2020.20027","url":null,"abstract":"The purpose of this study was to empirically estimate machine and labor costs for mechanization of viticultural processes and to assess the relative effect of mechanization options on viticultural costs. By identifying three external factors that determined the degree of optimal mechanization of three major viticultural processes, we developed a systematic typology of 12 unique vineyard types. To estimate the effects of the factors and processes on production costs, we analyzed the variance of more than 3400 single working time records of five German wine estates across three years with fixed and random effects. Mechanization of general viticultural processes, harvesting, and pruning strongly affected viticultural costs. Minimal pruning provided a cost savings potential of 58% for vineyards that permitted mechanized harvesting. Very steep slopes suffered significant cost disadvantages of up to 164% that could only partially be compensated by mechanization. We identified opportunities for wine producers to improve their economic profitability by increasing viticultural mechanization. The methodological framework developed can be applied to other wine regions with different cost settings and the analysis of big data sets from digitalization of viticulture. The results can aid wine producers and policymakers to choose cost-efficient viticultural systems and provide benchmarks to compare labor intensity.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"46 - 55"},"PeriodicalIF":1.9,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47467757","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}
Oak barrels are often used to flavor and color wine, beer, and distilled beverages. However, microorganisms can penetrate into the wood, making cleaning and sterilization difficult. This can lead to undesired microbial growth in the contents of the barrel during subsequent use. Information on heat penetration into barrel staves during steam treatment and associated thermal inactivation rates is scarce. Therefore, we incorporated heat transfer and Arrhenius-type death kinetics to build a mathematical model to predict the killing rate of the microorganisms when steam sterilizing a wooden barrel. First, we used this model to predict temperature profiles in barrel staves as a function of distance from the steamed surface and time of steaming. We then evaluated the thermal inactivation of microorganisms at 0.8 cm into the stave (the maximum wine penetration depth into a stave) to calculate the time needed to achieve a 5-log reduction in live cells. Using this approach, we found that the required sterilization times for Brettanomyces bruxellensis, Saccharomyces cerevisiae, and Leuconostoc mesenteroides are 9 min, 12 min, and 200 min, respectively. This result is useful for winemakers to determine how long they desire to steam a barrel to prevent growth and contamination of key microbes in their wine.
{"title":"Prediction of Effective Steam Sterilization Times for Wine Barrels Using a Mathematical Modeling Approach","authors":"Ruiye Yao, Grace Kwong, K. Miller, D. Block","doi":"10.5344/ajev.2020.20047","DOIUrl":"https://doi.org/10.5344/ajev.2020.20047","url":null,"abstract":"Oak barrels are often used to flavor and color wine, beer, and distilled beverages. However, microorganisms can penetrate into the wood, making cleaning and sterilization difficult. This can lead to undesired microbial growth in the contents of the barrel during subsequent use. Information on heat penetration into barrel staves during steam treatment and associated thermal inactivation rates is scarce. Therefore, we incorporated heat transfer and Arrhenius-type death kinetics to build a mathematical model to predict the killing rate of the microorganisms when steam sterilizing a wooden barrel. First, we used this model to predict temperature profiles in barrel staves as a function of distance from the steamed surface and time of steaming. We then evaluated the thermal inactivation of microorganisms at 0.8 cm into the stave (the maximum wine penetration depth into a stave) to calculate the time needed to achieve a 5-log reduction in live cells. Using this approach, we found that the required sterilization times for Brettanomyces bruxellensis, Saccharomyces cerevisiae, and Leuconostoc mesenteroides are 9 min, 12 min, and 200 min, respectively. This result is useful for winemakers to determine how long they desire to steam a barrel to prevent growth and contamination of key microbes in their wine.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"101 - 105"},"PeriodicalIF":1.9,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46063582","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 diurnal changes in vine water status and the appropriate time of day to measure leaf water potential (LWP) and stem water potential (SWP) were examined in Willamette Valley vineyards with north-south (N-S) oriented rows employing a single curtain, vertically shoot-positioned (VSP) canopy. Measurements of LWP and SWP were performed on Chardonnay and Pinot noir grapevines on seven cloudless days between bloom and harvest over two years. On warm days, LWP reached the daily minimum value by midday (1300 hr) and remained there for a longer duration when vines experienced moderate water stress (LWP < -1.20 MPa) than minor water stress (LWP > -1.20 MPa). However, on cool days, LWP reached the daily minimum later in the day (1400 hr to 1500 hr) in both stressed and unstressed vines. SWP reached the daily minimum level late in the day (1400 hr to 1600 hr) under all conditions and even increased between late morning and midday on two occasions. Thus, measuring SWP at midday consistently underestimates the greatest level of water stress experienced by vines in N-S oriented, VSP canopies. Results of this study show that LWP can be determined over a four-hour period starting at midday on warm sunny days when vines experience a moderate level of water stress: conditions when it is most critical to assess vine water status to schedule irrigation. SWP should be measured in the two-hour period between 1500 hr and 1700 hr under all conditions tested here in N-S oriented, VSP canopies.
{"title":"Appropriate Time to Measure Leaf and Stem Water Potential in North-South Oriented, Vertically Shoot-Positioned Vineyards","authors":"T. Tian, R. Schreiner","doi":"10.5344/ajev.2020.20020","DOIUrl":"https://doi.org/10.5344/ajev.2020.20020","url":null,"abstract":"The diurnal changes in vine water status and the appropriate time of day to measure leaf water potential (LWP) and stem water potential (SWP) were examined in Willamette Valley vineyards with north-south (N-S) oriented rows employing a single curtain, vertically shoot-positioned (VSP) canopy. Measurements of LWP and SWP were performed on Chardonnay and Pinot noir grapevines on seven cloudless days between bloom and harvest over two years. On warm days, LWP reached the daily minimum value by midday (1300 hr) and remained there for a longer duration when vines experienced moderate water stress (LWP < -1.20 MPa) than minor water stress (LWP > -1.20 MPa). However, on cool days, LWP reached the daily minimum later in the day (1400 hr to 1500 hr) in both stressed and unstressed vines. SWP reached the daily minimum level late in the day (1400 hr to 1600 hr) under all conditions and even increased between late morning and midday on two occasions. Thus, measuring SWP at midday consistently underestimates the greatest level of water stress experienced by vines in N-S oriented, VSP canopies. Results of this study show that LWP can be determined over a four-hour period starting at midday on warm sunny days when vines experience a moderate level of water stress: conditions when it is most critical to assess vine water status to schedule irrigation. SWP should be measured in the two-hour period between 1500 hr and 1700 hr under all conditions tested here in N-S oriented, VSP canopies.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"64 - 72"},"PeriodicalIF":1.9,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48563162","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. Arancibia, Emiliano Malovini, C. Agüero, F. Buscema, R. Alonso, M. Walker, L. Martínez
Preference host is an important factor affecting population dynamics in plant-insect interactions. In this research, the two main phylloxera genotypes found in Argentina (gB and gD) were tested on Vitis vinifera cvs. Cabernet Sauvignon, Malbec, Pedro Giménez, Chardonnay, Cereza, Criolla Grande, and rootstocks 1103 Paulsen, 101-14 Mgt, and SO4 using an excised root assay. Statistical analysis showed that survivorship was affected by the interaction of Cultivar and Time, while hatching was influenced by the interaction of Cultivar and Phylloxera genotype. Cultivar also influenced maximum number of adults, developmental time, as well as gross and net reproductive rates. Phylloxera genotype gB developed faster than gD, however, no other significant differences were found between both genotypes. Principal component analysis showed that Pedro Giménez and Criolla Grande grouped closely with high values of reproduction-related variables, suggesting they are the most preferable hosts, followed by Cabernet Sauvignon; while Cereza, Malbec, and Chardonnay were less suitable. None of the rootstocks allowed the establishment of phylloxera colonies. This study will help improve the biological understanding of phylloxera in Argentina and help develop tools for its management.
{"title":"Evaluation of Two Phylloxera Genotypes in Argentina on Six Vitis vinifera Cultivars and Three Rootstocks","authors":"C. Arancibia, Emiliano Malovini, C. Agüero, F. Buscema, R. Alonso, M. Walker, L. Martínez","doi":"10.5344/ajev.2020.20038","DOIUrl":"https://doi.org/10.5344/ajev.2020.20038","url":null,"abstract":"Preference host is an important factor affecting population dynamics in plant-insect interactions. In this research, the two main phylloxera genotypes found in Argentina (gB and gD) were tested on Vitis vinifera cvs. Cabernet Sauvignon, Malbec, Pedro Giménez, Chardonnay, Cereza, Criolla Grande, and rootstocks 1103 Paulsen, 101-14 Mgt, and SO4 using an excised root assay. Statistical analysis showed that survivorship was affected by the interaction of Cultivar and Time, while hatching was influenced by the interaction of Cultivar and Phylloxera genotype. Cultivar also influenced maximum number of adults, developmental time, as well as gross and net reproductive rates. Phylloxera genotype gB developed faster than gD, however, no other significant differences were found between both genotypes. Principal component analysis showed that Pedro Giménez and Criolla Grande grouped closely with high values of reproduction-related variables, suggesting they are the most preferable hosts, followed by Cabernet Sauvignon; while Cereza, Malbec, and Chardonnay were less suitable. None of the rootstocks allowed the establishment of phylloxera colonies. This study will help improve the biological understanding of phylloxera in Argentina and help develop tools for its management.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"94 - 100"},"PeriodicalIF":1.9,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45257148","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}
Dominique N Ebbenga, E. Burkness, M. Clark, W. Hutchison
Spotted-wing drosophila, Drosophila suzukii (Matsumura), is an invasive species to Minnesota that was first recorded in 2012. Since its arrival it has become a major pest of stone fruit and berry crops, including winegrapes. High fecundity and short generation times have allowed D. suzukii to flourish and spread throughout North America and Europe in a relatively short period of time. Laboratory and field trials were conducted between 2017 and 2019 to determine the risk of injury from D. suzukii in Minnesota winegrape varieties and to assess acetic acid (AA) levels in wine and juice samples from cold-hardy winegrape varieties in Minnesota. Results from risk of injury studies in 2017 and 2018 demonstrated a low risk of direct injury to intact grape berries. Winemakers, however, are concerned about the potential risk of D. suzukii infestations increasing AA-producing bacteria (e.g., Acetobacter spp.), known to expedite the development of sour rot in grapes. AA trials in 2017 and 2019 demonstrated significant increases in AA for select grape varieties as fly density increased. However, the 2018 AA trials with modified infestation protocols did not result in significant differences in AA. Our results are discussed within the context of improving integrated pest management programs for D. suzukii.
{"title":"Risk of Spotted-Wing Drosophila Injury and Associated Increases in Acetic Acid in Minnesota Winegrapes","authors":"Dominique N Ebbenga, E. Burkness, M. Clark, W. Hutchison","doi":"10.5344/ajev.2020.20008","DOIUrl":"https://doi.org/10.5344/ajev.2020.20008","url":null,"abstract":"Spotted-wing drosophila, Drosophila suzukii (Matsumura), is an invasive species to Minnesota that was first recorded in 2012. Since its arrival it has become a major pest of stone fruit and berry crops, including winegrapes. High fecundity and short generation times have allowed D. suzukii to flourish and spread throughout North America and Europe in a relatively short period of time. Laboratory and field trials were conducted between 2017 and 2019 to determine the risk of injury from D. suzukii in Minnesota winegrape varieties and to assess acetic acid (AA) levels in wine and juice samples from cold-hardy winegrape varieties in Minnesota. Results from risk of injury studies in 2017 and 2018 demonstrated a low risk of direct injury to intact grape berries. Winemakers, however, are concerned about the potential risk of D. suzukii infestations increasing AA-producing bacteria (e.g., Acetobacter spp.), known to expedite the development of sour rot in grapes. AA trials in 2017 and 2019 demonstrated significant increases in AA for select grape varieties as fly density increased. However, the 2018 AA trials with modified infestation protocols did not result in significant differences in AA. Our results are discussed within the context of improving integrated pest management programs for D. suzukii.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"106 - 112"},"PeriodicalIF":1.9,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42691316","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}
Scott C Frost, J. Sánchez, Caroline P. Merrell, R. Larsen, H. Heymann, J. Harbertson
Adjusting the soluble solids of the prefermentation must is a tool by which winemakers can manipulate the flavor profile of a wine. Total soluble solids (TSS) are often modified prior to fermentation by chaptalization or the addition of water, but can be modified also in the vineyard, by allowing the fruit to further mature on the vine. This work presents the effects of harvest maturity and prefermentation TSS on the flavor profile of Cabernet Sauvignon (CS) and Syrah (SY) wines. Fruit from each cultivar was harvested at three approximate maturity targets: 20 Brix (unripe), 24 Brix (ripe), and 28 Brix (overripe). Must from each harvest was first divided, then the TSS was adjusted to match each of the target maturities; for example, portions of the 24 Brix harvest were adjusted to 20 or 28 Brix. Descriptive analysis found 10 attributes that varied significantly among the CS wines and 14 attributes which varied significantly among the SY wines. Harvest maturity primarily impacted the CS aroma profile, as wines produced from unripe fruit showed increased green aroma, but wines produced from ripe/overripe fruit showed increased jammy berries aroma. Increasing the prefermentation TSS of the CS must increased the intensity of bitterness, hotness, and viscosity, but decreased the sourness. The SY wine flavor profile was impacted heavily by increasing the prefermentation TSS, which showed greater intensities of astringency, ethanol aroma, hot mouthfeel, jammy fruit aroma, rose aroma, solvent aroma, ethanol aroma, and viscous mouthfeel. SY fruit maturity significantly affected astringency and earthy aroma, but an interactive effect between harvest maturity and TSS was found for sulfur, cabbage aroma, and bitterness.
{"title":"Sensory Evaluation of Syrah and Cabernet Sauvignon Wines: Effects of Harvest Maturity and Prefermentation Soluble Solids","authors":"Scott C Frost, J. Sánchez, Caroline P. Merrell, R. Larsen, H. Heymann, J. Harbertson","doi":"10.5344/ajev.2020.20035","DOIUrl":"https://doi.org/10.5344/ajev.2020.20035","url":null,"abstract":"Adjusting the soluble solids of the prefermentation must is a tool by which winemakers can manipulate the flavor profile of a wine. Total soluble solids (TSS) are often modified prior to fermentation by chaptalization or the addition of water, but can be modified also in the vineyard, by allowing the fruit to further mature on the vine. This work presents the effects of harvest maturity and prefermentation TSS on the flavor profile of Cabernet Sauvignon (CS) and Syrah (SY) wines. Fruit from each cultivar was harvested at three approximate maturity targets: 20 Brix (unripe), 24 Brix (ripe), and 28 Brix (overripe). Must from each harvest was first divided, then the TSS was adjusted to match each of the target maturities; for example, portions of the 24 Brix harvest were adjusted to 20 or 28 Brix. Descriptive analysis found 10 attributes that varied significantly among the CS wines and 14 attributes which varied significantly among the SY wines. Harvest maturity primarily impacted the CS aroma profile, as wines produced from unripe fruit showed increased green aroma, but wines produced from ripe/overripe fruit showed increased jammy berries aroma. Increasing the prefermentation TSS of the CS must increased the intensity of bitterness, hotness, and viscosity, but decreased the sourness. The SY wine flavor profile was impacted heavily by increasing the prefermentation TSS, which showed greater intensities of astringency, ethanol aroma, hot mouthfeel, jammy fruit aroma, rose aroma, solvent aroma, ethanol aroma, and viscous mouthfeel. SY fruit maturity significantly affected astringency and earthy aroma, but an interactive effect between harvest maturity and TSS was found for sulfur, cabbage aroma, and bitterness.","PeriodicalId":7461,"journal":{"name":"American Journal of Enology and Viticulture","volume":"72 1","pages":"36 - 45"},"PeriodicalIF":1.9,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42435985","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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