Abstract:

The study aims to screen out the suitable urea spraying concentration to assist the leaf falling of sweet cherry in south China, and formulate reasonable growth control measures for the planting and development of sweet cherry, thus provide a theoretical basis for achieving stable yield of sweet cherry. The five-year sweet cherry trees (Summit) were used as the experimental material, we studied the effect of different concentrations of urea on the fallen leaves of sweet cherry via single spraying or multiple spraying. The results revealed that the leaf falling was obviously after spraying urea, the amout of fallen leaves was the largest after single spraying of 5% urea. But the effect of leaf falling was the best by multiple spraying, under which, the trees had earlier and quicker leaf falling, at the same time its amount of fallen leaves was the largest. In addition, after the single spraying of 5% urea, the tree body had a higher recovery and utilization rate of N element, so that the total nitrogen content in the leaves in the next year was the highest and there were greater numbers of new branches. This paper suggests that, in late autumn in Hangzhou area, single spraying of 5% urea should be conducted on the sweet cherry to assist the leaf falling and promote the sweet cherry to its dormant period, in order to be conducive to nutrient recovery and storage.

Key words: Hangzhou, sweet cherry, fallen leaves, urea, total nitrogen