Application of controlled-released urea combined with conventional urea on physiological indices, yield and quality of Chrysanthemum morifolium Ramat.

Nitrogen is one of the most important nutrients and plays a vital role in crop growth and yield production, rational nitrogen fertilization is essential to achieve an optimal yield and the desired product quality. Field experiments were conducted from 2009 to 2010 to compare the effects of controlled-release urea and conventional urea on the growth, yield and quality of Chrysanthemum morifolium. The results show that the physiological indices, including soluble protein content, chlorophyll content, nitrate reductase and root activities, are highest at the pregnant stage, and the indices in the treatments applied two kind of urea are higher than those of the control. The controlled-release urea and conventional urea applied as single basal application can improve growth and dry matter accumulation at the early stages of C. morifolium, while split fertilizations are more favorable to these in the later stages. The amounts of inflorescence number per plant and 100-inforencsence flesh weight are increased under both the controlled-release urea and conventional urea applications, while there are less effects on inflorescence diameters. Consequently, the yield increase is achieved mainly by increasing the inflorescence number per plant and 100-inforencsence flesh weight. The yields treated by split fertilization of both controlled-release urea and conventional urea are higher than those treated by single basal application, and the highest yield is obtained in the application of controlled-release urea combined with conventional urea. Compared with conventional urea application treatments, the controlled-release urea application treatments lead to significant increases of total flavonoid content, chlorogenic acid content, soluble sugar content and protein content of C.morifolium, and those of the treatment applied controlled-release urea combined with conventional urea are higher than those others. Taking account of yield and quality, the split fertilization of controlled-release urea combined with conventional urea is the optimum under this experiment condition.