Accelerated rooting of carnation ‘Red Baron’ by temperature pre-treatment

Abstract

Rooting of carnation cuttings was promoted by storage temperatures above 0°C with an inverse relationship between the level of temperature and the duration of the treatment. The effect of temperature on root dry weight was far more important than the effect of duration of storage. A long storage and a high temperature increased the incidence of Fusarium. Storage at temperatures lower than 13°C gave better results with auxin applied after storage, while temperatures higher than 13°C gave better results with a pre-treatment of auxin. During storage for 14 days at 9°C, the position of the cuttings had no clear effect on rooting. Horizontal storage, however, appeared to be unfavourable. Removal of 0.5 cm of the base of the stem after storage nullified the storage effect. Carbohydrates in the removed pieces decreased during storage, more so at 13°C than at 0°C. Anatomically, an acceleration of cell division at the base of the cutting was observed during storage at 9°C as compared to 0°C. At a commercial nursery, storage of cuttings for 12 days at 14°C improved rooting by 84% compared to storage at 0°C. The presented technique tends to shorten the expensive and vulnerable period from planting to rooting.