Growth and Cut Flower Yield of Roses as Affected by Age of Rooted Cuttings

Abstract

This study was conducted to investigate the effect of age of transplants, propagated by cutting,of two cut rose (Rosa hybrida Hort.) cultivars on their subsequent growth and yield in an effort to develop an efficient cutting propagation method for domestic rose cultivars. Two cultivars used in this study were a standard type ‘Pink Aurora’ and a spray type ‘Yellow King’. Cuttings were prepared as single node cuttings each with a five-leaflet leaf and were stuck in rockwool cubes (5 cm × 5 cm × 5 cm, UR, Korea) at two different dates. Cuttings rooted for either 30 (stuck on Jan. 20, 2009) or 48 days (stuck on Jan. 2, 2009) were transplanted into a rockwool slabs (10 cm × 15 cm × 100 cm, UR, Korea) on the same date, 18 Feb. 2009. Plant growth and cut flower quality were investigated for two successive harvests during the period of Jan. to July in 2009. In both cultivars, 48 days old plants showed some growth of the shoot and root before transplanting. However,in the case of 30 days old plants before transplanting no noticeable growth of the shoot and root was obserable in ‘Pink Aurora’, while only shoot growth, but not root growth to the bottom of the rooting medium, was observed in ‘Yellow King’. This suggested cultivar-specific responses that in this experiment a spray type ‘Yellow King’ showed greater growth rate during the rooting stage than a standard type ‘Pink Aurora’. In the measurement of growth and cut flower yield after transplanting, the 48 days old standard type ‘Pink Aurora’ produced greater number of cut flowers per plant than 30 days old plants, whereas their mean stem fresh weight was recorded smaller than that of the 30 days old plants. For ‘Yellow King’, 30 days old plants showed greater stem length, flower width, number of five-leaflet leaves per stem, stem fresh weight, and number of cut flowers per plant than 48 days old plants. Therefore, growth and yield were significantly affected by cultivar and age of the rooted cutting, and additional research is needed on the effect of age of rooted cuttings in more cultivars.