| The experiment was carried out to evaluate the yield and quality of tomato under greenhouse with the treatment of coated urea.The results showed that coated urea increased the yield of tomato remarkably compared with common urea; the yield of D60 was the highest,being 68.85 t/hm2,and the increase rate was 39.2% compared to CK and 17.2% compared to urea;the yield difference between the two varieties of coated urea(D90 and D60) was un-significant.Coated urea could increase the fruit number of single plant and the weight of single fruit.The nitrogen utilization efficiency of D90 and D60 was 65.5% and 108.8% higher respectively than urea;the nitrate content in fruits of D90 was 56% lower than that of urea and 4.4% higher than that of CK;and the nitrate content in fruits of D60 was 51.6% lower than that of urea and 15% higher than that of CK.The Vc and amino acid contents of D90 were the highest,being 100% and 246% higher respectively than that of CK,and 22% and 100% higher respectively than that of urea;the Vc content of D60 was similar to that of urea,while the amino acid content of D60 was 48% higher than that of urea.The soluble sugar content of D60 was the highest and that of urea was the lowest.The order of comprehensive quality index was: D90 >D60>U.It can be concluded that coated urea is effective in improving the yield and quality of tomato,especially in improving the safety quality. The best coated urea for tomato production was that with a releasing period of 60 d. |