Effects of Short-term Low NO_3~- Treatment during Seedling Stage on Growth,Yield and Quality of Hydroponic Cucumber

This experiment was carried out with greenhouse cucumber(Cucumis sativus L.)seedling grown in nutrient solutions with different concentration of NO3-,for a short period treatment.The growth and development indicators,photosynthetic characteristics,yield and quality of cucumber plant were investigated during treatment and recovery phases.The results indicated that short-term low NO3- treatment reduced vegetative growth and photosynthetic characteristics of cucumber seedlings.However,after a period of recovery,there was no difference in cucumber yield,while the fruit quality was improved as compared with the control.T2(5 mmol·L-1 NO3-)achieved the highest stomatal conductance,intercellular CO2 concentration and net photosynthetic rates which increased 15.25%,4.90%,3.28% compared with the CK,respectively.T2 had a low impact on fruit yield but its VC content increased 14.92% compared with the CK,and the nitrate content of T2 was 20.52% lower than that of the CK.