Effects of nutrient and water stress on vegetative and reproductive growth in Vitis vinifera L.

Two watering and two nutrient regimes were applied to small vines established in pots and grown under greenhouse conditions. With water, a comparison was made between water adequacy (WH) and intermittent water stress (WL); with nutrition, between nutrient sufficiency (NH) using fertiliser-enhanced potting medium and insufficiency (NL) with one-fifth fertiliser application. NL reduced major growth parameters - shoot length, stem weight and leaf weight - more than did WL. Both NL and WL reduced node and leaf number, but only NL reduced internode length, leaf area and weight. WL had bigger effects when combined with NH than with NL. WL, especially when combined with NH, advanced maturity by ten days. Effects of W and N on pH, malic acid, tartaric acid and total soluble solids (°Brix) were different. The °Brix values were similar in WH and WL, but were less in NH than in NL. The treatments interacted in pH, malate and tartrate: pH was highest in WL/NH and lowest in WH/NH; malate tended to be less at both WL and NL, while tartrate concentration tended to become smaller from WH to WN but greater from NL to NH. No significant changes in the levels of citric acid, anthocyanin or reducing sugars were observed as a consequence of any treatment. Thus, although levels of stress due to WL or NL may have been different, the differences in the effects on several variables indicate that there is no general response to stress but that responses vary according to the factor inducing the stress. The level of reduction in variables measuring vegetative growth was 2– to 3-fold greater than induced changes in juice composition. Advancement of maturity would suggest a potential value of intermittent water stress combined with adequate nutrition in areas with short seasons. Low-nutrient soils might be desirable in areas where other factors are likely to induce strong growth.     

Towards a simple indicator of water stress in grapevine (Vitis vinifera L.) based on the differential sensitivities of vegetative growth components

Responses of grapevine vegetative growth components to mild, medium and severe soil water deficits were used to identify simple and sensitive indicators for early diagnosis of water stress. Soil water deficit was characterised as the fraction of transpirable soil water (FTSW) remaining in a water‐depleted rootzone. Growth components included the number of emerged leaves on first (Ist) and second (IInd) order lateral branches, the leaf area and internode length of each phytomer of Ist order lateral branches, and the frequency of IInd order lateral branching. These components were measured in a greenhouse on Shiraz (syn. Syrah) grapevines, over a 38‐day period of stabilised soil water regimes. Leaf emergence rate, final leaf area and final internode length of lateral branches I were relatively insensitive to mild and medium water deficits. They only decreased in response to severe water deficits. The frequency of IInd order lateral branching showed a similar trend, but was inhibited at severe water deficits. The leaf emergence rate of lateral branches II was highly sensitive to FTSW, and decreased even in response to mild water deficits. Because measurement of leaf emergence rate is a time consuming process, further analysis of the data was undertaken to identify a simpler but similarly effective indicator of cumulative water deficit. Accordingly, we established that the final length of lateral branches I was sensitive to medium water deficits, while the final ratio of the number of leaves on lateral branches II to the number of leaves on lateral branches I, was sensitive to even mild water deficits. Both of these composite indicators (derived variables) were relatively easy to measure and showed potential as early indicators of water deficits. They were more sensitive to FTSW than was predawn leaf water potential. Moreover, the final ratio of the number of leaves on lateral branches II to the number of leaves on lateral branches I was even more sensitive to FTSW than was stomatal conductance.     

Suitability of pre‐dawn and stem water potential as indicators of vineyard water status in cv. Tempranillo

Background and Aims: Irrigation management requires the collection of up‐to‐date information that allow growers to make rapid decisions, water potential being one of the most used parameters in irrigation scheduling. The goal of this research was to determine whether predawn (Ψpd) and stem (Ψs) water potential can be used equally well, quantifying the effect external factors have on the relationship between them. Methods and Results: Ψpd, mid‐morning (Ψs‐m) and noon (Ψs‐n) stem water potential were measured at seven cv. Tempranillo vineyards. Climatic conditions, vine growth and fruit load affected daily water potential dynamics. A greater decline of Ψs occurred when temperatures were higher and there was no dew formation, as well as under larger canopies and fruit load. While the relative impact of these variables on water potential was not particularly high, it was by no means negligible. Conclusions: Data collected in this study did not favour Ψpd, Ψs‐m or Ψs‐n as a preferred measure to evaluate plant water status. It is important to remark that similar Ψpd values do not necessarily indicate the same level of deficit, and that similar Ψs values do not always mean similar water availability. Therefore, a straightforward interpretation of Ψpd and Ψs can sometimes be misleading. Significance of the Study: The results obtained provide significant explanation to the lack of agreement in the literature regarding the most suitable time to measure water potential. Vineyard managers and scientists should select it according to the level of stress expected, climatic conditions and irrigation frequency.     

Developmental variation in sensitivity of Vitis vinifera L. (Shiraz) berries to soil water deficit

A large-scale, long-term irrigation experiment was established near Waikerie in the South Australian Riverland to investigate the feasibility of controlling berry size and ripening at the vineyard scale with modern irrigation systems. Irrigation treatments were devised to impose water stress, by withholding irrigation, during four periods of berry development after flowering of Vitis vinifera (variety Shiraz). Varying water deficits were achieved during each period and between the four seasons, which were climatically diverse. In one season water deficit during the period after flowering resulted in the greatest reduction in berry weight compared with that of well-watered vines, however, in another, water deficit during this period had no effect on berry weight. By comparison, berries appeared to be insensitive to water deficit during the month before harvest in all four seasons. A soil water deficit index was derived to compare the varying levels of water deficit between treatments and seasons on berry development. Deficit effects on berry development were assessed using either comparative growth rate or berry weight near harvest. Regression analysis of berry development against soil water deficit indicated that berries were most sensitive to water stress during the post flowering period.     

Relative proportions of seed, skin and flesh, in ripe berries from Cabernet Sauvignon grapevines grown in a vineyard either well irrigated or under water deficit

Relationships between the fresh mass of seed, skin (exocarp), and flesh (mesocarp) in six different berry size categories, were assessed on ripe fruit from Cabernet Sauvignon grapevines exposed to either High (H), Control (C) or Low (L) water status during post‐veraison berry growth in a vineyard. Berries harvested from each treatment were segregated into six mass categories in order to distinguish between changes in fresh mass components associated with general variation in berry size (on well‐watered grapevines), and those associated with berry size differences due to water stress. Berry fresh mass across all treatments ranged from about 0.4 to 2.0 g. Fresh mass components for both H and C berries comprised approximately 5% seed, 15% skin, and 80% flesh, regardless of variation in berry size, although there was some increase in seed mass relative to whole‐berry fresh mass in larger berries. Berry growth (as inferred from fresh mass at harvest) was much less sensitive to water deficit than published reports for grapevine shoot growth. Midday leaf water potentials around –1.20 MPa (Control) were not sufficient to inhibit berry growth. However, midday water potentials around –1.50 MPa (Low water status) inhibited berry growth by 13–18% of that attained by grapevines grown at high water status (i.e. treatment H where midday leaf water potentials remained around –1.00 MPa). Inhibition of berry growth by water deficit was attributed almost exclusively to reduced growth of mesocarp tissues (for most berry size categories). Water deficit thus increased the proportion of whole‐berry fresh mass represented by seeds and skin (for most berry size categories). Changes in those proportions due to irrigation treatments exceeded differences associated with general (non‐stress) variation in whole‐berry fresh mass. Excluding adverse environmental impacts on whole‐berry fresh mass, our results point to a limited role for variation in berry size per se as a factor determining the solute concentration of juice or wine derived from different sized fruit. By implication, and for all categories of whole‐berry fresh mass represented here, late season water deficit can result in ripe fruit with more skin and seed tissues (relative to whole‐berry fresh mass) compared with well‐watered control fruit.     

环剥对红地球葡萄果实发育和枝条生长的影响

研究了环剥处理对红地球葡萄果实发育及枝条生长的影响。结果表明：结果枝果穗下节间环剥处理不改变红地球葡萄果实发育的动态规律,只改变其峰值高低;环剥可促进果实生长发育,果实鲜重、纵横径、可溶性固形物含量均显著增加;环剥还有抑制副梢生长,促进新梢老熟和增加老熟节数的作用。     

椰子水腰果梨复合果酒的研制

以椰子水和腰果梨为原料,对椰子水腰果梨复合果酒的发酵工艺进行研究.通过中心组合试验设计和响应面分析优化发酵工艺.最佳工艺为发酵温度为20℃、SO2添加量为100mgkg、腰果梨汁添加量为8％.以最佳酿造工艺制成的椰子水腰果梨复合果酒酒体澄清透亮,香气清淡,风味独特.     

滴灌方式及定额对北疆冬灌棉田土壤水盐分布及次年棉花生长的影响

为探寻解决干旱区棉田冬季灌水问题,明晰北疆棉田不同冬灌方式及灌水定额对土壤水分、盐分分布以及翌年棉花生长及产量的影响,采用大田试验方法,以未冬灌大田作为对照(CK),设置滴灌和漫灌2种灌水方式下4个梯度的灌水定额(1 800、2 400、3 000、3 600、 3600 m3/hm²)共9个处理进行冬灌试验,分析了冬灌灌水后到播种前0~300 cm土层的水分、盐分的动态变化以及翌年各处理棉花的出苗率、群体生理指标(群体光合势、群体净同化率、叶面积指数)和产量数据。结果表明,冬灌对次年播前土壤水盐分布及含量的大小均具有一定的影响,无论漫灌还是滴灌方式进行冬灌,随灌水定额增加土壤水分和盐分的影响深度也随之加深,灌水定额达到3 000和3 600 m3/hm²时,冬灌对土壤水盐影响深度可达300 cm。冬灌可显著改变次年播前土壤盐分的自然分布状态,有效淋洗并降低上层土壤盐分含量;相对漫灌方式而言,滴灌冬灌方式土壤水分入渗更加均匀且规律明显。冬灌对次年滴灌棉花的生长发育及产量均具有重要影响,冬灌后次年棉花群体指标与未冬灌处理的差异随冬灌灌水定额的增加愈加显著,灌水定额3 000 m3/hm²滴灌冬灌处理的次年棉花群体光合势与叶面积指数较未冬灌处理分别提升34.30%和42.60%;冬灌有利于次年棉花产量的提高,滴灌冬灌灌水定额3 000、3 600 m3/hm²处理时的棉花产量相对未冬灌处理分别增产10.66%和12.36%。综合考虑冬灌方式及灌水定额对次年土壤水盐分布及棉花生长和产量的影响,研究认为滴灌条件下灌水定额3 000 m3/hm²的冬灌在试验条件下比较适宜,既可淋洗盐分至耕层以下300 cm处,亦可获得6 107.75 kg/hm²的较高产量。     

Influence of water and nitrogen deficit on fruit ripening and aroma potential of Vitis vinifera L cv Sauvignon blanc in field conditions

S‐Cysteine conjugate precursors of three volatile thiols were monitored in Vitis vinifera L cv Sauvignon blanc grapes during fruit ripening to assess the influence of vine water and nitrogen status on the grape aroma potential in field conditions. Four dry farmed plots were studied in the Pessac‐Léognan and Graves appellations (Bordeaux area) in 1998, which was a very dry vintage, and in 1999, when regular summer rainfall occurred. Soil water‐holding capacity ranged from very low to high. Soil total nitrogen content was related to soil organic matter content, which was highly variable on the four plots. Vine vigour was enhanced by both high water and nitrogen status. Major compounds in grapes depended mainly on vine water status. Water deficit‐stressed vines produced small berries with low sugar and low total acidity. Grape aroma potential was highest in vines under mild water deficit and moderate nitrogen supply. Severe water deficit stress seemed to limit aroma potential, as did nitrogen deficiency. Consequences for site selection and irrigation management for Sauvignon blanc are discussed. Copyright © 2004 Society of Chemical Industry     

Berry size and vine water deficits as factors in winegrape composition: Anthocyanins and tannins

Soluble solids, seed tannin, skin tannin, and skin anthocyanin were measured in fruit from Cabernet Sauvignon vines that had experienced either High, Control or Low water status during ripening. Berries from each treatment were segregated into 6 size categories at harvest in order to test independently for relationships due to size compared with those due to water deficits. Berry content of all solutes increased approximately in proportion to the increase in berry size. Deviations from proportionality caused Brix and anthocyanin concentration (mg per unit berry fresh mass) to decrease, and the concentration of skin tannin to remain unchanged or decrease slightly with increasing berry size. The concentration of seed tannin did not decrease and appeared to increase with berry size in multiple-seeded berries. In comparison with skin tannin or anthocyanin content, seed tannin content varied more with berry size and less with vine water status. In addition to decreasing berry size, water deficits increased the amount of skin tannin and anthocyanin per berry and the concentrations of skin tannin and anthocyanins, but did not significantly affect the content or concentration of seed tannin. The results show that there are effects of vine water status on fruit composition that arise independently of the resultant differences in fruit size. The effect of vine water status on the concentration of skin tannin and anthocyanin was greater than the effect of fruit size on those same variables. However, the increases in skin tannin and anthocyanin that accompanied water deficits appear to result more from differential growth sensitivity of inner mesocarp and exocarp than direct effects on phenolic biosynthesis.     

Effectiveness of a water-saving super-absorbent polymer in soil water conservation for corn (Zea mays L.) based on eco-physiological parameters

BACKGROUND: The objective was to study soil water conservation and physiological growth of corn (Zea mays L.) using water‐saving super‐absorbent polymer (SAP) at 30 kg ha^?1. The effectiveness of SAP was studied under three irrigation levels (adequate, moderate and deficit) using a new type of negative hydraulic pressure controlled auto‐irrigator in the years 2009 and 2010 in a greenhouse at Beijing, P.R. China. RESULTS: Eight weeks after sowing, plant height and leaf area increased significantly by 41.6 and 79.6% under deficit irrigation for SAP treatment. The SAP had little effect on shoot dry mass under adequate and moderate irrigation but increased it significantly by 133.5% under deficit irrigation. Similarly, the efficiency of water use also increased by 97.1%. Leaf water potential under adequate and moderate irrigation differs slightly for SAP application, whereas under deficit irrigation the values were exceeded significantly by 27.8%. The superior growth and water use efficiency of corn treated with SAP under deficit irrigation was ascribed to maintenance of higher relative water contents in leaves as well as intercellular carbon dioxide concentration, net photosynthesis and transpiration rate. CONCLUSIONS: Our results suggested that plant growth and different physiological activities are restricted by drought stress and the application of super‐absorbent polymer could conserve soil water, making same available to plants for increased growth and biomass accumulation especially under severe water stress. Thus, application of SAP is a suitable soil management practice for the locations characterised by severe water stress. Copyright © 2011 Society of Chemical Industry     

用ORP监控鲜切果蔬臭氧水消毒的实验研究

研究了用氧化还原电位(ORP)监控臭氧水对鲜切果蔬的消毒灭菌过程,通过不同ORP的臭氧水消毒实验发现,将鲜切果蔬浸入ORP超过800mV的臭氧水中超过30s可以使细菌总数下降约2个数量级。通过改变臭氧浓度和水温的方法研究了臭氧水ORP的影响因素,得出了提高臭氧气体浓度和低温制冷有利于制取高ORP臭氧水的结论。结果表明,利用ORP监测臭氧水的消毒能力是可行的。     

采后热水和乙醇处理对枸杞鲜果腐烂的控制及品质的影响

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