Gray system theory based analysis of hard branch cuttage of Salix oritrepha in alpine area

The relational grades of 5 hard branch cuttage treatments and 8 observing indicators of Salix oritrepha were conducted with relational grade analysis method. The results showed that the relational degrees among observing indicators of S.oritrepha cuttage with hard branch was survival rateroot lengthstem diameterheightnumber of first class branchfresh weight of aboveground biomassnumber of lateral root. The order of relational degree of 5 treatments was plastic mulchsimple plastic greenhousenursery bagseedling cupopen field. Root length, stem diameter and height were the main indicators for the survival rate and plastic mulch treatment was the proper method for rapid propagation in alpine area.