{"title":"南北向垂直种植葡萄园叶片和茎干水势测量的适宜时机","authors":"T. Tian, R. Schreiner","doi":"10.5344/ajev.2020.20020","DOIUrl":null,"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":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5344/ajev.2020.20020","citationCount":"4","resultStr":"{\"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\":null,\"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\":null,\"pages\":null},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2020-10-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.5344/ajev.2020.20020\",\"citationCount\":\"4\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"American Journal of Enology and Viticulture\",\"FirstCategoryId\":\"97\",\"ListUrlMain\":\"https://doi.org/10.5344/ajev.2020.20020\",\"RegionNum\":3,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"BIOTECHNOLOGY & APPLIED MICROBIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"American Journal of Enology and Viticulture","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.5344/ajev.2020.20020","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
Appropriate Time to Measure Leaf and Stem Water Potential in North-South Oriented, Vertically Shoot-Positioned Vineyards
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.
期刊介绍:
The American Journal of Enology and Viticulture (AJEV), published quarterly, is an official journal of the American Society for Enology and Viticulture (ASEV) and is the premier journal in the English language dedicated to scientific research on winemaking and grapegrowing. AJEV publishes full-length research papers, literature reviews, research notes, and technical briefs on various aspects of enology and viticulture, including wine chemistry, sensory science, process engineering, wine quality assessments, microbiology, methods development, plant pathogenesis, diseases and pests of grape, rootstock and clonal evaluation, effect of field practices, and grape genetics and breeding. All papers are peer reviewed, and authorship of papers is not limited to members of ASEV. The science editor, along with the viticulture, enology, and associate editors, are drawn from academic and research institutions worldwide and guide the content of the Journal.