Effects of Prun ing and Growth Regula tors on the Bud Growth andDevelopment of P icea c rassifolia Seedlings

Buds on leaders and lateral branches of 5-year-old and 7-year-old Picea crassifolia was seedlings weretreated with different pruning and growth regulator daubing. Removing ap ical bud of Qinghai sp ruce could p romotesome lateral and dormant buds growing and breaking, imp rove branch growth. The effect of different growth regulators and p runingmodels to the buds of P. crassifolia distinct. Among all treatments, treatment effect of removing ap ical bud on trunk and lateral brancheswas superior to that of sp indle-mode p runing and fense-mode p runing, cutting still remaining 3 full buds on stems could significantly decrease the number of buds and then lessen the amount ofbranching, it was the worst one for 7-year-old seedlings. Whittling top buds could increase the quantities of shootand bud on shoot, simultaneously the total length of shoot was also lengthened. 6BA could effectively p romote thegrowth and development of sp ruce buds and branches, CHOUZH IBAO ismost ineffective and even rep ressive amongall treatments, for 5-year-old trees , the influence of p runing and growth regulator on the break-bud number of budson lateral tress was significant, however, for 7-year-old trees, it’s insignificant, and the interaction between themwas remarkable in the treatments to 7-year-old seedlings, but it’s not to 5-year-old seedlings. Daubing 6BA on theremained buds after removing ap ical budswasmore effective to boost the growth and development of buds in P. crassifolia and helpful to p roduce more buds and branches, it’s a kind of the best treatment to P. crassifolia seedlings,cutting or p lastering budswith CZB were unsuitable to the establishment and development of cutting orchard of P.crassifolia.