Propagation of Abiesfraseri by softwood stem cuttings

Abstract

Effects of collection date, crown position, and indole-3-butyric acid concentration on rooting and subsequent vegetative growth of softwood cuttings taken from 14-year-old Fraser fir (Abiesfraseri (Pursh) Poir.) Christmas trees were studied. Indole-3-butyric acid levels producing maximum rooting (approximately 50%) varied with crown position and date of severance. Abaxial bending during rooting was greatest for cuttings from the first collection (June 23). Increasing indole-3-butyric acid concentrations decreased abaxial bending of cuttings from the first two severance dates. One year after rooting, plagiotropism was still most pronounced on cuttings collected the first date as a result of active bending of the original cutting segment. Terminal shoot growth was greatest for cuttings from the first and third collections. Lateral budbreak was superior on cuttings collected on the first date. When all factors are taken into consideration, the best combination of rooting and vegetative growth was obtained from upper-crown cuttings which were collected just prior to lignification, wounded, and treated with 1500 ppm indole-3-butyric acid. After one season (one growth flush), rooted softwood cuttings were comparable to 2-year-old plants (two flushes) propagated by hardwood cuttings. The temporal separation of rooting from shoot extension may have been responsible for improving initial vegetative growth.