Effect of cutting size on the rooting of Thuja occidentalis 'Columna'

Abstract

Rooting process plays a key role in the vegetative propagation of the ornamental coniferous, and insufficient rooting causes substantial losses in the propagation industry. Cuttings of Thuja occidentalis ‚Columna' planted in the greenhouse of Mihai Viteazul Nursery Garden from Turda were examined after selecting the cuttings in three size categories. Experimental design included three cutting lengths (10, 15 and 20 cm) and each were growing without rooting hormones. Cutting length is an important factor that affecting rooting. The exact length of the cuttings is dependent upon the selected species used in vegetative propagation. The presence of leaves on a cutting is important also for root formation and development. In our experiment we planted stem cuttings with leaves and length between 10 and 20 cm. The first measurement it was take in the 12 th week of rooting process, the second was take in the 18 th week of the rooting process. Significant differences were shown among cuttings from the three category in root number per cutting but not in root length per cutting after 18 weeks. Medium length cuttings (15 cm) had significant influence on root number per cuttings. For optimal rooting, we recommend using 15 cm long cuttings.

Effect of the Cutting Length and Propagation Period on Three Thuja Occidentalis Varieties

“…Root number decreased at the TOD (Figure 3c) cuttings propagated in July compared to May propagation period. Szász-Len et al (2015b) reported that 15 cm cuttings obtained the highest root number at Thuja occidentalis 'Columna'. Hormone treatments could also greatly increase the number of adventitious root formation (Panea and Blada, 2016).…”