Study On Key Technology Of Nursery Seedlings Of Atyipiex Canexcens From American

Atyipiex canexcens（Pursh）Nutt．(AC)is a fast-growing quasi evergreen forage shrubwith tolerance to cold, drought, salinity, infertility, and has been introduced and cultivated inXinjiang, Qinghai and Shaanxi, proved to be a good pioneer tree species in ecologicalmanagement.However the import of AC seeds greatly improved the cost of domestic cultivation. Thelow seed viability from seedling propagation and the instable germination rate both cause thenursery stock from seedling propagation has much variation in quality and could not reach thestandard of mass plantation.Recently, twig cuttage breeding technology has developed markedly and was used inseedling production extensively. Scion nursery ageing, scion insufficiency in large scaleproduction, and low rooting and survival rate caused by over demand water spray in hightemperature period are the questions commonly encountered in the use of the technology.Moreover, root bury is necessary in the afforestation of AC because of its large crown. Theroot quality therefore is affecting the survival rate of forestation.In the current research we built a fertile effect model through parallel experiments andorthogonal regression experiment in order to analyze the problems in AC cuttage breedingmass production, improve the cuttage breeding tech, and determine the optimum N, P, and Kproportion suitable for promoting seedling quality in Jingchuan, Gansu Prov.. This researchcould provide theoretical basis for high quality AC nursery stock production. The conclusionsare listed as below:1.Intensive clipping is the key technology in AC scion nursery regeneration. Secondaryclipping can improve scion quantity and quality much more than the ordinary first clipping.This clipping method is good for large scale production.2.Sufficient watering in scion nursery three to seven days before cuttage can lift thequality of cutting wood and the cuttage survival rate by2.6%.3.Substrate tray cuttage breeding can help scion root development and growth.Transplanting with substrate almost eliminates the acclimation period, shortening transplantrejuvenation period by8-10days, improving transplant survival rate by13.9%. Seedling output rate is also improved.4.Late July to early August is the annual high temperature period in Jingchuan area,Gansu. Ca.50%sunshade can improve the rooting rate of cuttage wood by4.3%, shorteningadventitious rooting time.5.Belowground dry matter accumulation is increased most by P, and followed by N andK for AC individuals. The cross effects in increasing AC belowground dry matter areobserved significantly in N-P and N-K.6.The root growth of AC twig cuttage seedlings is robust under the fertile condition of N227.0-257.6kg/ha and P180.78-216.56kg/ha, meanwhile the belowground biomass is higherthan140g. The forestation survival rate and quality can be notably improved by thiscondition.7. It can improve seedlings quality to apply the rules of AC twig cuttage seedlings.