| Abstract: Five imported American thin-shelled pecan varieties, Chengyin 1, Chengyin 4, Chengyin 6, Chengyin 10 and Chengyin 15, were observed from six aspects of botanical characteristics, biological characteristics, phenology, fruit economic characters, resistance and growth results, and the fruit nutritional components were analyzed to make comprehensive evaluation. The results showed that five varieties of Hickory pecan in Hui County, Longnan County, Gansu Province had good growth and development, strong adaptability, high resistance to bacterial black spot and anthracnose, and better resistance to insect and disease than local varieties. The phenology of germination, flowering, fruity, deciduous leaf and the length of male inflorescence and stigma color of female flowers were relatively obvious. The germination and leafing stage of walnut was 15-20 days later than that of common walnut. The walnut blossomed in early and middle May, which could avoid the harm of late frost in early and middle April. The appearance of the fruit basically maintains the original characteristics, but the fruit is small, which needs to be further studied. The nuts have four types of flavor: light, sweet, sweet and luzhou-flavor. The kernel yield is more than 50%, and the nutrition is rich, the content of monounsaturated fatty acid is about 5 times that of ordinary walnut, the content is up to 70%. The flowering and fruiting of Chengyin No. 15 were obviously earlier and the yield was the highest, followed by Chengyin No. 4 and Chengyin No. 6 had better early fruiting, and the yield of five American thin shell pecans was significantly increased. |
