During this period, the crown began to shrink, and the fruit yield decreased until the economic yield could not be maintained. This period is the period when the life activities of fruit trees begin to decline. During this period, the top of backbone branches weakened, the growth of new shoots decreased obviously, the number of vegetative branches decreased and the number of fruiting branches increased. Among the fruit branches, short fruit branches and short fruit branches account for the vast majority. However, due to the weakening of vegetative growth, the tree body reserves insufficient nutrients, the fruit setting rate is not high, the flowers and fruits are seriously dropped, the fruit is small, the yield is obviously reduced, and the quality is not high; The periphery of the crown and the top of the main branch shriveled and dried up, the length of the tree weakened, and the main branches were incomplete. Due to the weakening of tree length, the stress resistance decreases and the disease is serious. During this period, the crown hole is easy to germinate clustered branches. If properly utilized, COVID-19 can be gradually formed and expanded year by year to maintain a certain output. However, when the yield falls below 15000kg/ha in the late mature period, it has lost its economic value and the whole garden should be updated in time.

The task of plastic trimming is to determine the content and method of trimming on the premise of determining whether it has economic value or not. If it has economic value, we should first strengthen the comprehensive management of soil, fertilizer and water, increase the retraction of large branches and carry out local renewal on the basis of enhancing nutritional growth; Choose strong branches on the back to change their heads, cultivate new big branches and fruiting branches, gradually restore the crown and maintain a certain yield; When it is confirmed that it has lost its economic value, the whole park should be updated in time.