Impact of Nitrogen Concentration on Stock Plant Yield and Cutting Performance of 'Purple Small Leaf and 'Raspberry See'Bougainvilleas

摘要

Effects of nitrogen (N) concentration on yield, cutting quality, and rooting performance were investigated to establish a nitrogen-based fertility program for bougainvillea stock plants. Stock plants of 'Raspberry Ice' and 'Purple Small Leaf were fertigated with N at concentrations of 100,200, or 300 mg-L~(-1). Overall 'Purple Small Leaf stock plants produced more and longer cuttings than 'Raspberry Ice', however rooting performance was better with 'Raspberry Ice'. The greatest cutting yields were achieved with N at 200 mg-L~(-1), and shorter cuttings with smaller leaf areas occurred when stock plants were fertilized with N at 100 mg-L~(-1). Cutting diameter was not influenced by N concentration. Undesirable leachate nitrate nitrogen values were observed from stock plants fertilized with N at 300 mg-L~(-1) after cuttings were harvested 14 and 22 weeks after potting. Based on these results, stock plants of 'Raspberry Ice' and 'Purple Small Leaf should be fertilized with N at 100 to 200 mg-L~(-1).