Research Of Pruning On Jujube Canopy Characteristic Yield And Transpiration

Through appropriate pruning, form tree size and reasonable canopy structure suitable for jujube tree planting density, both the crown ventilation, good lighting, increase production, But also to minimize the invalid transpiration for a large amount of crown, thus improving the efficiency of water production. The test researched 4 years low tree and high-density planting pear trees in jujube science and technology experimental park of Zizhou County in northern Shaanxi, the experiment set up 7 kinds of treatment were: One-sided shape, Y-shaped, Standing shape, Cylindrical shape, Open center shape, Natural round shape and CK which is not carried out pruning in summer. In this paper, research the effects of different pruning treatments on canopy structure and characteristics, jujube tree growth and fruit and transpiration of in Northern jujube tree, provide the basis for the low tree and high-density cultivation and pruning. The main conclusions are as follows:(1)Summer pluck center pruning is very important, directly impact on the changes of canopy characteristic index, thereby affecting the reproductive growth of jujube. In the experiment measured gap fraction, LAI, diaphanous rate and light interception density and so on, in these characteristic indicators, LAI, diaphanous rate and light interception density are most important.In the flowering stage (July 3) naturally round shape leaf area index is 1.22, light transmission rate is 40.61%, light interception density is 34.01 mol. m^-2.d^-1, flowering fruit setting rate is higher than others; cylindrical shape has small volume, leaf area index is 0.83, light transmission rate is 63.54%, light interception density is 22.53 mol. m^-2.d^-1, flowering fruit setting rate is higher than others.It can be pruning tree growing by the canopy leaf area index and under the canopy radiation density.(2) Proper pruning promote the local growth and inhibit the overall growth. Jujube tree pruning later, promoted rapid growth for the width of new flush and leaf area; At the same time, pruning control tree vigor and reduce the tree size, thereby reducing the excessive consumption of nutrients for shoot growth, natural round-shaped volume 45% smaller than CK, one-sided shape and cylindrical shape volume 60% smaller than CK to September 10; through pruning regulates the relationship between vegetative growth and reproductive growth , and the rate of fruiting was significantly increased after pruning, the rate of fruiting CK 50% less than natural round shape, 43% less than cylindrical shape. (3) The tree canopy size and leaf area index and other characteristics of indicators, direct impact on the output of jujube. Study found that for 4 years pear jujube, to early September, planting density is 111 plants/mu,tree volume of 3.2m³, leaf area per unit volume is 2.45 m²/m³, leaf area index was 1.9, the total radiation under the canopy was 13.38 mol. m^-2.d^-1, the tree canopy structure is reasonable and with high yield. Natural round shape formed reasonable canopy structure and good light condition by properly pruning, so it has the highest yield to 2054.83kg/mu, 2.6 times the CK, consumed less water to obtain a higher yield.(4) Though proper pruning can form reasonable tree shape and have a great influence on water consumption of jujube. Cylindrical shape has little transpiration and reduced by 70% compared to CK. To early September, tree volume of Cylindrical shape is 2.36m³, leaf area per unit volume is 1.56m²/m³, leaf area index is 1.51, the total radiation under the canopy is 18.63 mol. m^-2.d^-1. Although the yield per tree less than Y-shape, but with high yield per unit volume, compared to other treatment, the water consumption of at least the highest yields in output. Such as the one-sided and cylindrical tree shape, by increasing tree crown and plant density to increase yield per acre. Studies suggest that treatment of 7, the natural round shape and Cylindrical shape are high yield and water conservation, as a reference when pruning a tree.