A Study On The Pollution-free Cultivation Techniques For Superior Cultivars Of Zizyphus Jujuba

Zizyphus jujuba is a traditional non-timber forest tree in China, with large cultivation area listed as number one in the seven top dried fruit in China. In jujuba industry, it has been seriously damaged by the spread of Lygocoris lucorum (Meyer-Dur.), and the chemical pesticide abuse is another damage both to the human health and the environment that we live. To solve these problems, we devised field tests for control efficiency of different kinds of botanical pesticide (Juglans regia green husk, Ginkgo biloba leaves, Capsicum annuum, Allium Sativum), various concentration of the extracts, and various application methods at Jujuba Species Breeding Base in Cang County, Hebei Province. Fruit cracking of germplasm at Jujuba Breeding Base was evaluated and the effect of the spray of calcium solution on the cracking rate was investigated. The main results are as follows:1. At growing periods of Jinsixiaozao and Dongzao jujuba (leaflet stage, bud stage, young fruit period), each kind of control efficiency is significantly different among different experimental treatments. As a whole, Juglans regia green husk has highest control efficiency, Ginkgo biloba leaves was the second. Capsicum annuum, Allium Sativum were worse. Based on these results, it was concluded that chemical pesticide could be partially replaced by the employment of Juglans regia green husk and Ginkgo biloba leaves.2. Fruit cracking is most directly caused by water exposure. Increased spraying concentration and application frequency of CaCl2 solution could reduce cracking rate to some extent. However, the application of calcium solution could not avoid the cracking problem.3. An investigation on cracking rate and cracking index of 128 cultivars in Jujuba Breeding Base at Cang County was carried out, which resulted in the classification of the cultivars, combined with the results from the immersion test for 20 selected cultivars.4. This thesis also made some suggestions on technical regulations for cultivation of Jinsixiaozao jujuba green food grade AA on the basis of several years of our research group, and compiled a draft of " Technical specification for cultivation of Ziziphus jujuba cv. Jinsixiaozao at green food AA grade" which will be benefit to the future standardization cultivation of Jinsixiaozao.