硝酸钙对厚皮甜瓜坐果节位叶片衰老及果实产量和品质的影响

以厚皮甜瓜迎春为试材，研究了叶面喷施不同浓度硝酸钙对坐果节位叶片衰老及果实生长和品质的影响。结果表明，坐果节位雌花开放后，叶面喷施10、 20、 30 mmol/L 的硝酸钙均可延缓坐果节位叶片叶绿素、 可溶性蛋白质含量的下降，提高叶片的净光合速率（ Pn ）和过氧化物酶（POD）、 超氧化物歧化酶（SOD）、 过氧化氢酶（CAT） 等抗氧化酶活性，降低丙二醛（MDA） 含量，提高果实的小区产量、 可溶性固形物和可溶性糖含量，其中20 mmol/L 的硝酸钙处理效果与对照差异显著。叶面喷施20 mmol/L 硝酸钙，可延缓厚皮甜瓜坐果节位叶片衰老，提高厚皮甜瓜的果实产量和品质。

Effects of calcium nitrate on leaf senescence in fruiting nodes and yield and quality of fruits of muskmelon

 In order to study the effects of calcium nitrate on the senescence of leave in fruiting nodes and the fruit yield of muskmelon, successive two foliage dressing experiments were conducted and three different spray concentrations of calcium nitrate (10 mmol/L, 20 mmol/L and 30 mmol/L) were tested at the bearing fruit flowering stage. The results show compared with CK, all the three  Ca(NO₃)₂ spray concentrations can delay the decreases of the contents of chlorophyll and soluble protein, increase the activities of antioxidant enzymes and the net photosynthesis rate (Pn), and decrease the MDA content of leaves in the fruiting nodes. Both the plot yield and fruit quality are increased by the sparying ofCa(NO₃)₂, and the difference is significant between spraying 20 mmol/L Ca(NO₃)₂  and CK. The research indicates that spraying 20 mmol/L Ca(NO₃)₂ can be used to postpone the senescence of leaves in the fruiting nodes and increase the fruit yield and quality.