前言果树生产的大小年现象,不仅造成产量低(大、小年平均)而不稳,而且导致果实品质不良、树势衰弱及病虫害的猖獗。克服大小年的途径要采取多方面的综合措施,除加强肥水管理以保证树体的营养需要,合理修剪以调节生长和结果的关系外,最直接、有效的措施是疏花疏果。大年通过疏花疏果使着果量符合于负载量,即保证树体的合理叶果比例。这样,不仅当年可以有较高的产量、较好的品质,而且能够进行正常的花芽分化,为下年丰产打下基础。目前我国生产上一般采用人工疏花疏果,但效率低、成本高,作业多有不便,不适应大面积栽培的需要。化学疏花疏果从三 Introduction The size-year-round phenomenon of fruit tree production not only results in low yield (large and small annual average) and instability, but also leads to poor fruit quality, weakness of trees and rampant pests and diseases. To overcome the size of the year to take a comprehensive range of measures to be taken, in addition to strengthening the management of fertilizer and water to ensure the nutritional needs of the tree, pruned to adjust the relationship between growth and outcome, the most direct and effective measure is thinning and thinning. New Year by thinning fruit thinning fruit volume in line with the load, that is, to ensure that the proportion of trees reasonable leaves. In this way, not only the current year can have a higher yield, better quality, but also to normal flower bud differentiation, lay the foundation for the next year’s high yield. At present, the production of flowers in our country generally adopts thinning and thinning, but the efficiency is low, the cost is high, there are many inconveniences in operation, and it is not suitable for the needs of large-scale cultivation. Chemical thinning fruit thinning from three