【作者】 庞秀明；

【导师】 康绍忠； 王密侠；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2005， 硕士

【摘要】 本文就甘肃民勤荒漠绿洲区覆膜西瓜在调亏灌溉条件下的耗水规律与调亏模式进行了研究。试验设在甘肃民勤县农技中心农场内。该试验采用当地常用灌水量作为标准灌水量,以2/3、1/2 和1/3 的标准水量作为亏水度;按照西瓜的生理生长特性划分为:播种-开花、开花-坐果、坐果-膨大和膨大-成熟4 个生育阶段作为试验的调亏阶段;试验设置10 个处理(含一个对照),每个处理两次重复;采用单阶段和全生育期各阶段组合调亏,试验从5 月1 日(播种)开始至8月17 日(采果)结束,历时共109 天,取得了如下的研究成果:　(1)在播种-开花期内对叶片气孔导度和蒸腾速率日变化研究表明,充分供水的叶片气孔导度和蒸腾速率大于水分亏缺条件下的叶片气孔导度和蒸腾速率,　2/3 亏水的处理4 光合速率和叶片水平水分利用效率均大于对照;坐果-膨大期亏水阶段内,2/3 亏水的处理6 叶片光合速率、气孔导度和水分利用效率均大于1/2 亏水的处理3,对照的蒸腾速率高于水分亏缺处理。　(2)通过对西瓜地上和地下部分生长量的研究表明:在播种-开花期内,经过2/3 标准水量亏水后复水,能够使西瓜的主蔓、根、叶片和花等器官存在着补偿生长效应;在全生育阶段亏水处理8 根冠比较为理想。　　(3)耗水量和灌溉水量的关系上表明,耗水量随着灌溉水量的增加而增大;西瓜的作物系数最大值出现在坐果-膨大期,这也是西瓜耗水的关键期。　(4)产量最高的是坐果-膨大期内进行2/3 亏水的处理6(单阶段亏水),产量非但没有减少,反而高出对照3.81%;在全生育期均亏水的处理8 虽然减产5.01%,但节水12.92%;产量与耗水量和灌溉水量均呈显著的相关关系;与其它处理对比,在全生育期均进行亏水的处理8 的产量水平水分利用效率和灌溉水利用效率最高。通过综合分析品质发现,处理8 的品质较优,在经过了两周的储存后,除果肉硬度比储藏前高外,瓜皮硬度和可溶性固形物在品质上均低于储存前。(5)试验采用4 个不同的水分生产函数模型对比研究发现: Jensen模型适宜于民勤地区西瓜缺水敏感指数研究,其缺水敏感顺序为;坐果-膨大>膨大-成熟>开花-坐果>播种-开花;更多还原

【Abstract】 The paper studied water requirement and deficit patterns of watermelon under RDI in arid-hungriness oasis area, Gansu province. The experiment was conducted in the farm of the center of agriculture and technology in Minqin county, Gansu province. The average irrigation of the area was used for the normal irrigation of experiment. 2/3, 1/2 and 1/3 of normal irrigation was used for the deficit of the experiment. According to growth characteristic of watermelon, four growth stages was use for deficit stages of the experiment, as follows: seedling-flowering, flowering-fruit bearing, fruit bearing-swelling and swelling-maturing, There were ten treatments and two repetition including one controlled treatments. The deficit of single stage and whole growth stages was used. The experiment was started from the first May to the seventeenth August, 109 days. The research fruit was as follows: (1) In the stage of seedling–flowering ,the research about diurnal change of leaf conductance, transpiration, photosynthesis and leaf WUE indicated that the leaf conductance and transpiration of full water supply were bigger than those in water deficit, that photosynthesis and leaf WUE of 2/3 of normal irrigation(treatment 4) were bigger than those of controlled treatment. In the deficit stage of fruit bearing-swelling, the photosynthesis, leaf conductance and leaf WUE of 2/3 normal irrigation (treatment 6) was bigger than those of 1/2 normal irrigation (treatment 3), and transpiration of the controlled treatment was bigger than that of the treatments of water deficit. (2) According to the research about biomass of watermelon, the compensatory effect was occurred in caudexes,root, leaves , flowers and so on, watering again after 2/3 deficit. The root/shoot was best than that of other treatments. (3) The relation of ET and irrigation was indicted that ET would become big if irrigation became big. The crop coefficient made clear that the key stage of consuming water of watermelon was the stage of fruit bearing-swelling (4) The highest production was treatment 6 whose production was higher 3.81% than controlled treatment. The treatment 6 was irrigated capacity of 2/3 normal irrigation in the stage of fruit bearing-swelling. The production of treatment 8 which was reduce water capacity was lower 5.01% than that of controlled treatment, but its water-saving was 12.92%. The relation of production with ET and irrigation wad correlative evidently. Compared to other treatments, the production WUE and IUE of treatment was the biggest. According to analyzing synthetically quality, the quality of treatment 8 was the best. After two weeks, the quality of watermelon was increased about the flesh rigidity, but the hull rigidity and soluble solids concentration were decreased. (5) The experiment was used 4 models of water-production function. The model of Jensen was the best than other models. It could reflect water-stressed sensitive index of watermelon in Minqin county, Gansu province. The order of water-stressed sensitivity of watermelon was fruit bearing-swelling, swelling-maturing, flowering-fruit bearing and seedling-flowering.更多还原