EFFECTS OF IRRIGATION FREQUENCY ON ROOT-FORMATION AND SHOOT GROWTH OF SPRAY CHRYSANTHEMUM CUTTINGS IN SMALL JUTE PLUGS

Small plugs of organic, fibrous material (jute) were used as a propagation medium for spray chrysanthemum cuttings instead of the more conventional, pre-fertilized compressed peat blocks. A complete nutrient solution was supplied to the jute plugs by means of ebb-and-flow irrigation. Four different irrigation frequencies (IF) were compared, i.e. 96, 24, 6 and 1 day(-1). During the root initiation stage, the irrigation treatments had little effect on the cuttings. Once a new root system had been generated, a strong positive correlation between IF and growth was observed. Shoots of rapidly growing cuttings contained relatively high levels of nutrients and low non-structural carbohydrate levels and had a high turgor. These results demonstrate that during propagation from cuttings, growth may be limited by the availability of water and minerals. In the case of chrysanthemum cuttings in small jute plugs, factors limiting growth can be overcome by frequent irrigation with a complete nutrient solution.