EFFECT OF POTASSIUM FERTILIZATION ON QUALITY OF CUCUMBER IN SOLAR-GREENHOUSE

The effect of potassium fertilization on cucumber quality in solar-greenhouse was studied. Cultivar Jin You-1 was planted in soil with different potassium levels.The result showed that the dry matter of cucumber fruits were about 4%～5%, and it increased as the potassium fertilizer increased. When proper potassium fertilizer were used, the main nutriments of cucumber fruits, such as Vc, soluble sugar and soluble protein content were all increased remarkably. However, when the amount of potassium fertilizer(K 2O)were more than 40～60kg/667m2, the above nutriments presented decreasing trends. In the range of 0～60kg/667m2, The contents of tannin and organic acid reduced significantly as potassium fertilizer increased, but the effect was minished while more than 60kg/667m2 potassium fertilizer(K 2O)were used. The more potassium fertilizer were used, the less the nitrate content produced.These indicated that if proper potassium fertilizer were used, the nutritional level and the flavour or taste quality of cucumber fruits could be increased obviously. Potassium fertilizer played a positive role in the reduction of the nitrate content.