Effect of Phenological Stage and Rooting Enhancers on Physiological Parameters in Stem Cuttings in the Process of Rhizogenesis of Rosa × alba ‘Maiden’s Blush’

Abstract

Once-blooming roses belong to difficult-to-root. One-bud leafy cuttings have limited storage capacity, due to the small size of the stem, and are exposed to prolonged stress conditions. The objective of this study was to examine if the treatment of the cuttings of Rosa × alba ‘Maiden’s Blush’ with plant origin preparations as rooting enhancers may increase their rooting percentage, chlorophyll a/b, and proteins concentration in leaves. The cuttings were prepared from shoots in four phenological stages: flower buds closed, flowers open, immediately after petal shedding, and 7–14 days after petal fall. The following were used: 0.4% indole butyric acid (Ukorzeniacz Aaqua), 0.2% naphthalene acetic acid (Ukorzeniacz Baqua), Bio Rhizotonic; Root Juice™, and Bio Roots. Controls included untreated cuttings. The highest rooting percentage was obtained after two treatments with 0.6% Bio Rhizotonic (81.5%), compared to the control (55.0%), using cuttings from shoots with flower buds closed, but the rooting enhancers did not show any unequivocal impact on rooting percentage in cuttings of all phenological stages or affected improvement this feature in cuttings harvested 7–14 after shedding petals with low root ability. However, the action of plant preparations affected positively higher soluble proteins and chlorophyll content. The plant-origin preparations can be used as alternatives to chemicals in nursery production.