Characteristics of absorption,distribution and utilization of foliar applied 15N-Urea in Autumn in "Hongdeng" sweet cherry

The characteristics of absorption,distribution and utilization of foliar applied 15N-urea in autumn and the effect of foliar spray of urea on the fruit quality under the condition of field cultivation by using seven-year-old Hongdeng sweet cherry(Prunus.avium L.var.Hongdeng/Daqingye) were studied.The results showed that 16.30%-17.27% of the 15N-urea was lost with the fallen leaves,and the rest 82.73%-83.70% 15N was absorpted.The stored nitrogen compound could be rapidly transported into the new organs in the next year,but the characteristics of transportation and distribution was differential.15N regurgitant and stored from branch leaves was transported to the new shoot leaves firstly,which was advantageous to vegetative growth.With time,it took on a polar distribution characteristic,then 15N regurgitant and stored from spur leaves mainly transported to the blossom organs and fruits,which was advantageous to blossoms and fruit set of sweet cherry.Our results showed that foliar application of urea could increase the fruit weight by 21.84%,improve the fruit sugar content and sugar/acid by 11.98%,21.84% compared to ck,and it could also improve the important aroma contents of fruit,such as hexanal,2-hexenal,(E)-2-hexen-1-ol,benzaldehyde.