中文摘要：

通过盆栽试验研究了植物生理调节剂对4种叶菜类蔬菜硝酸盐含量和产量的影响。结果表明,对于第一季蔬菜,2种土壤中减量施肥喷施3类植物生理调节剂与NPK处理比较,小白菜硝酸盐含量显著降低,而其产量略有下降,油麦菜硝酸盐含量略有下降,但其产量基本相同。对于第二季蔬菜（仅喷施调节剂）,2种土壤中各处理萝卜菜硝酸盐含量和产量基本相同;长沙土壤中各处理空心菜硝酸盐含量和产量变化较小,而宁乡土壤中第一季施NPK处理的空心菜硝酸盐显著高于其他处理。除宁乡土壤油麦菜收获后NPK处理土壤硝酸盐含量显著高于减量施肥外,其他3种蔬菜收获后各施肥处理土壤硝酸盐含量差异较小。说明施用植物生理调节剂可减少化肥施用,降低叶菜类蔬菜硝酸盐含量,同时可保持蔬菜产量。此外,蔬菜硝酸盐含量与蔬菜种类和土壤类型有关。

英文摘要：

In order to investigate the effect of plant physiological regulators and fertilization on nitrate accumulation and yield in leafy vegetables with different fertility,four vegetables were treated with auxin,gibberellins and microelement amino acid chelate in combination with kinds of conventional fertilization methods.The results indicated that the yield of pakchoi in two soils slightly decreased,but nitrate content significantly reduced by spraying three plant physiological regulators with 30% or 50% of conventional fertilization;while the yield of lettuces was roughly the same and nitrate content slightly decreased with the same treatments.Radish sprouts and water spinach grown on basis of the first fertilization soil were only treated by spraying plant physiological regulators.The nitrate content and yield of radish sprouts was roughly the same;while the nitrate content and yield of water spinach was not significantly different between treatments,except the nitrate content with NPK treatment in Ningxiang soil was significantly higher than the other treatments.The soil nitrate content after four leafy vegetables harvested had a very small influence,except that was significantly decreased in Ningxiang soil with different treatments compared to NPK treatment after water spinach harvested.It suggested that spraying plant physiological regulators could reduce the fertilization usage and nitrate accumulation in vegetable,but maintain the vegetable yields.However,the nitrate content in vegetable was related to the types of vegetable and soil.