Study On Control Technique Of Jun Jujube Fruit Setting And Fruit Cracking Rate In Aksu Area

Ziziphus jujuba Mill plays a vital role in special forest fruits industry in Xinjiang, and growing themhas now become a new way to increase local farmers’ income. The natural conditions in Xinjiang are verysuitable for growth of Ziziphus jujuba Mill, especially in the south. With the rapid development of jujubeindustry, Xinjiang has become the biggest jujube cultivating province in China. But in the process of jujubecultivation, the phenomenon of low fruit setting and fruit cracking rates is very serious, which not onlycauses a large number of nutrient loss, but also reduces the Jujube yield. This research studied the controltechnique of the fruit seeting and fruit cracking rates of jun-jujube, one of mainly planted Jujubes in Aksuarea, by observing its annual phonological period. Meanwhile, water spraying, fertilizer application, boraxand GA3spraying, girdling, shedding shoot thinning and other factors related to fruit setting of jun-jujubewere conducted. In addition, the influence of fertilizer application on its fruit cracking was explored. Theresults were shown as follows:(1) The germination of jun-jujube in Aksu area started in mid-April, its leaf expansion started in lateApril, flower bud appearanced in early May, flower season started in late May and ended in late June whichlasted until late August. It begun to bear fruit in early June and had two physiological fruit-drop periods,which were early August and early September respectively. Fruit coloration started in the middle ofSeptember and the fruit matured at the beginning of October. It started falling leaves in late October.(2) The treatment of spraying water could increase the humidity, which would not only increase theviability of pollen, but also reduce the incidence of coke flower. Thus, it proved that this method was ableto improve the fruit setting rate. Water spraying once every three days had the best effect and fruit numberper plant reached10.5.(3) Fertilization had a positive influence on growth of shedding shoot of jun-jujube, fruit setting,increase of jujube yield and soluble solids content. Jun-jujube trees with the application of8kg sheepmanure showed significant difference from the contrast.(4) The treatment of spraying GA3had effects on jun-jujube fruit setting and the differences betweeneach group were significant.30mg/L had the greatest effect on promoting growth of shedding shoot ofjun-jujube, and its length was able to reach34.7cm.20mg/L had the least influence on jun-jujube fruitsetting, and the average fruit bearing per shedding shoot of jun-jujube was12.8.(5) With the increase of girdling width, fruit setting rate ascended at first and descended later. Of allthe treatments, fruit setting rate reached maximum36.8%with a girdling width of0.4cm, more than that inthe control group by10.5%.(6) With the increase of the percentage of jun-jujube shedding shoot, fruit setting rate ascended atfirst and descended later. When the percentage was20%, fruit setting rate reached maximum36.8%, morethan that in the control group by10.5%.(7) With the treatment of spraying Ca（NO3）2, groups showed significant differences in fruitcracking rate from the contrast. By application of spraying25mg/L Ca（NO3）2on jun-jujube, the fruitcracking rate reached minimum7.6%, less than that in the control group by39.6%.(8) The main internal cause of jun-jujube fruit cracking was low content of Ca2+in the pericarp.