Research On Crown Structure And Canopy Parameters Of High Yield Peach Garden

Chinese peach production is the maximum in the world, whose area and crop is the first in the world. But the unit area yield and the export amount is low. It is the key factor for peach high yield that different crown structure,which have a great influence on tree crown structure parameters、canopy parameters、yield and quality. The present test was undertaken with ’Beijing Red’、’Kubo’ and ’Yanhong’ peach fruit to find out the difference in crown structure、canopy parameters and the effect of yield and quality by crown structure and different branch quantity. The main results are as follows:1. In high-yield and high-quality orchards, leaf area index increased with the increase of new branch growth, and reached the maximum value from late May to early June, then changed gently. While the change trend of canopy light transmittance、total direct radiation、total scattering and total radiation under the canopy, which reached the minimum value from late May to early June, was opposite to that of leaf area index. And the change trend could stay at a suitable range after summer pruning. There was no obvious difference between the two kinds of peach tree shape in leaf area index, canopy light transmittance, radiation under the canopy, and the index of fruit quality and yield.2. There are some differences in leaf area index change of different varieties of peaches. In spring, leaf area index of ’Beijing Red’ peach, whose fruit branch mainly is middle and short branch, increased faster with the increase of new branch growth, and reached the maximum value in late May,earlier than ’Kubo’ peach tree. From late June, the leaf area index of ’Beijing Red’ and ’Kubo’ peach changed gently.3. The present test was undertaken with ’Yanhong’ peach fruit to find out the difference in crown structure and canopy parameters by the difference of airtight degree. The results show that: with the airtight degree of peach tree enlarge,the crown structure parameters,included trunk perimeter、tree height、main branch perimeter、main branch height、main branch projection length,enlarge more. With the airtight degree of peach tree enlarge,in the period of the increase of new branch growth,in spring,the growth rate of leaf area index enlarge more,and the leaf area index reach the maximum earlier; And the change trend of canopy light transmittance、total direct radiation、total scattering and total radiation under the canopy was opposite to the trend of leaf area index.4. The present test was undertaken with ’Yanhong’ peach fruit to find out the differences of crown structure parameters、the yield and quality in different space of tree canopy. The results show that: in different space of tree canopy,the proportion of branch type is mainly the same. But it is obviously difference in branch quantity、yield and quality. In the branch quantity distribution , there is about 25% in the inner region、about 35% in the middle region、about 40% in the outer region. In the yield distribution , there is about 23% in the inner region、about 37% in the middle region、about 40% in the outer region. In the quality, from the inner to the outer, the single fruit weight increased, soluble solid content increased, smooth exponential decline, coloring index rose.5. The present test was undertaken with ’Yanhong’ peach fruit to find out the appropriate crown structure parameters in high yield peach garden. The results show that: the peach tree of proper tightness, have good light、high yield and quality. Because of this, in the heavy fruit period, the suitable main crown structure parameters of natural open shape ’Yanhong’, of 3500-3800kg produced per Mu and row spacing 4×4.5m is: the high of the tree is 4.19-4.3m;the quantity of main branch is 111 per Mu;the minimum value of canopy light transmittance is 25﹪; the angle of the main branch is about 32°. After the winter pruning, the suitable branch quantity is 22900-32500 per Mu,the suitable proportion of L-M-S branches is 1/2/1.