调亏灌溉对塑料大棚甜瓜光合特性、果实产量和品质的影响

以充分灌水作为对照,在伸蔓期和果实膨大期对甜瓜品种‘情网’进行轻度和中度水分亏缺处理,研究调亏灌溉对塑料大棚栽培甜瓜光合特性、果实产量和品质的影响。结果表明:与充分灌水相比,果实膨大期轻度水分亏缺处理下光合速率变化不显著,蒸腾速率和气孔导度分别提高8%和75%,单株灌水量减少6%,水分利用效率和果实硬度分别提高6%和10%,固酸比增大,产量无显著差异。与充分灌水相比,伸蔓期轻度、中度及果实膨大期中度水分亏缺处理下甜瓜果实产量分别降低25%、24%和27%,水分利用效率分别降低了19%、11%和18%。综合考虑亏缺处理对甜瓜各项指标的影响,果实膨大期进行轻度水分亏缺效果最佳,在不降低产量的情况下,显著改善甜瓜果实品质,提高水分利用效率,具有推广价值。

Effects of regulated deficit irrigation on photosynthetic characteristics,fruit yield and quality of melon under plastic green house conditions

Melon cv.‘Qingwang’was adopted to study the effects of regulated deficit irrigation on the photosynthetic characteristics,fruit yield and quality of melon under plastic house conditions.The treatments included the sufficient water supply during the whole growing period (control),low and mod-erated water deficits at the stages of vine-extending or fruit-expanding.The results showed that compared with the control,low water deficit treatment at the stage of fruit-expanding had no significant effect on the net photosynthetic rate and fruit yield,increased the transpiration rate and stomatal conductance by 8% and 75%,respectively,decreased the amount of irrigation water by 6%,increased the water use effi-ciency and fruit firmness by 6% and 10%,and increased the ratio of total soluble solid/titrable acidity. Compared with the control,low and moderate water deficit treatments at the stage of vine-extending and moderate water deficit treatment at the stage of fruit-expanding decreased fruit yield by 25%,24%, 27%,respectively,and decreased water use efficiency by 1 9%,1 1%,18%,respectively.Comprehensively considering the effects of water deficit treatments on each indicator measured in melon,low water deficit treatment during the fruit-expanding stage can improve the fruit quality without reducing yield,and in-crease water use efficiency.Thus,low water deficit treatment during the fruit-expanding stage has the po-tential to be popularized.