微喷对冬小麦冠层微环境日变化及叶片水势的影响

采用裂区试验,以矮抗58为试验材料,在前期滴灌控水处理下,探究了不同的微喷处理对冬小麦冠层微环境、叶片水势和产量的影响。结果表明,在冬小麦灌浆后期微喷10 mm能显著降低冠层温度、二氧化碳摩尔分数,提高相对湿度、旗叶叶片水势。MW2处理(滴灌底墒水、拔节水和开花水,并在灌浆后期微喷10 mm)的产量、千粒质量最高,分别为6 952.39 kg/hm~2、45.44 g,均显著高于其他处理(P0.05)。相关分析显示,产量与冠层温度呈极显著负相关、与旗叶叶片水势极显著正相关、与冠层相对湿度显著正相关。可见,滴灌底墒水、拔节水和开花水,并在灌浆后期微喷10 mm,能够改善冬小麦冠层微环境,缓解空气高温对小麦的胁迫,显著提高千粒质量,增加产量。

Impact of Micro-sprinkler Irrigation on Diurnal Variation of Microenvironment of Canopy of Winter Wheat and Their Leaf Water Potential

This paper investigated the impact of micro-sprinkler irrigation on diurnal change in microenvironment of winter wheat canopy, their leaf water potential and yield using split-plot experiment. We used the cultivar Ai-kang58 as the model plant. The results showed that irrigating 10 mm of water at late grain-filling stage could signif-icantly reduce the temperature and carbon dioxide concentration of the canopy, whereas increasing the relative hu-midity and leaf water potential of the canopy. The treatment of drip-irrigating at sowing, jointing and flowering stages, together with a further 10 mm of irrigation at late filling stage, gave the highest yield (6952.39 kg/hm2) and 1000-grain weight (45.44 g), which were significantly higher than those in other treatments. Analysis showed that the yield was negatively related to canopy temperature (P<0.01), while positively related to leaf water potential (P<0.01) and relative humidity of the canopy (P<0.05). Therefore, drip irrigation at sowing, jointing and anthesis stages with further 10 mm of irrigation at late grain-filling stage could optimize the canopy microenvironment and alleviate thermal stress, significantly increasing yield and grain weight as a result.