不同生育期水分胁迫对延后栽培葡萄产量与品质的影响

Effect of water stress in different growth stages on grape yield and fruit quality under delayed cultivation facility

为寻求最佳的葡萄果实产量及品质的水分调控阈值,将延后栽培葡萄划分为萌芽、抽蔓、开花、果实膨大、着色成熟5个生育阶段,各生育期设3个供水水平（即土壤相对含水率为75%-100%、65%-90%、55%-80%）,开展了上述3种供水水平下葡萄果实生长、产量、品质及水分生产效率的研究。结果表明,延后栽培葡萄有2个明显的高、低峰膨大周期,第1个高峰期出现在膨大期前16 d,平均横向和纵向膨大速率分别达到0.747和0.959 mm/d;葡萄横径2次膨大高峰出现在膨大期第44-52 d,纵径比横径推迟1 w,平均膨大速率只有0.134 mm/d,比横向小0.063 mm/d。抽蔓期中度水分胁迫处理和开花期中度胁迫处理的膨大速率在果实膨大初期表现出了明显的复水补偿效应,中后期则出现了复水补偿结束后的再减小过程。萌芽期中度胁迫处理对提高葡萄产量、水分生产效率和灌溉水利用效率有利,其值分别达到36333、7.69、10.27 kg/m^3,着色成熟期轻度胁迫处理次之。着色成熟期轻度胁迫下,可溶性固形物、维生素C、葡萄糖、总糖等营养成分均显著高于生育期充分供水处理（P〈0.05）。综合考虑产量、水分生产效率、灌溉水利用效率及果实品质等指标,最佳延后栽培葡萄水分调控处理为着色成熟期轻度胁迫,即着色成熟期土壤相对含水率为65%-90%、其余生育期土壤相对含水率为75%-100%。该研究可为设施延后栽培葡萄土壤水分精准管理提供依据。

Soil water content is the main factor affecting plant growth and dry matter accumulation. The study of grape fruit enlargement, fruit quality and yield under delayed cultivation facility in cold area is of important significance for fresh grape＇s balanced supply. A field experiment was conducted during the grape growing season in Zhang Ye, China in 2013 to investigate the influence of water stress in different growth stages on grape growth and yield under delayed cultivation facility. The growing season of delayed planting grapes was divided into five growth stages including germination, vining, flowering, fruit enlargement and colored mature. Three soil water treatment levels were designed in each growth stage by either drying or adding water to reach the designed soil water content（75%-100% field capacity, 65%-90% field capacity, and 55%-80% field capacity）. Grape yield, quality and water efficiency were studied under above water regimes. The results showed that there were two distinct high and low peaks in delayed planting grapes enlargement cycle. The first enlargement peak appeared in the former 16 days of enlargement period, and the average horizontal and vertical enlargement rate reached 0.747 and 0.959 mm/d. The grapes＇ second transverses enlargement peak appeared in the first 44-52 days, the vertical diameter was postponed one week, and the average rate of inflation was only 0.134 mm/d, which was smaller than the transverse by 0.063 mm/d. There was significantly positive correlation between grape fruit＇s transverse diameter enlargement rate and longitudinal diameter enlargement rate at the same time except in fruit expanding period of 52-59 days, and the grape fruit transverse and longitudinal enlargement were strongly synchronous. In the early fruit enlargement stage, fruit enlargement rate showed evident re-watering compensation effects under the VS（moderate water stress in grape＇s vining stage） and FS（moderate water stress in flowering stage） treatments, and later the rate was slow again. Before July 30th（within 30 days of fruit enlargement stage） the processing of fruit growth rate of FS treatment has been at a high level, and the fruit cumulative transverse diameter and longitudinal diameter enlargement were up to 16.82 mm and 20.16 mm in this period, respectively, which reached 71.1% and 78.23% of the final grape fruit sizes. That meant fruit enlargement rate of early enlarging period determined the final grape fruit size, which must be paid attention to in the process of grape plant. Grape yield, water use efficiency（WUE）, irrigation water use efficiency（IWUE） of GS（moderate water stress in germination stage） were higher than other treatments, and its value reached 36 333 kg/hm2, 7.69 kg/m^3, 10.27 kg/m^3, respectively; and CM treatment（mild stress in coloring maturity stage） ranked second. So from the yield, WUE and IWUE point of view, the best water treatment was carrying out moderate water stress in germination period（the minimum soil water content was 55% field capacity, upper limit was 80% field capacity）, and the rest of the growth period carried out sufficient water supply（the minimum soil water content was 75%, upper limit was field capacity）. Grapes soluble solids, VC, fructose, glucose, total sugar of CM treatment were 19.0%, 1.66 mg/50 mL, 9.64%, 13.46%, 24.76%, respectively, which were significantly higher than CK（P〈0.05）. Therefore, with a comprehensive consideration of yield, WUE, IWUE and fruit quality indicators, the optimal water regulation treatment under delayed cultivation was CM, namely mild water stress（soil water content was 65% field capacity-90% field capacity） in ripe period, and sufficient water supply（soil water content was 75% field capacity-100% field capacity） in other periods. The research can provide valuble information for precise management of soil moisture in grape＇s growth period, and to achieve the purposes of water saving and grape quality and production improvement.