Effect of Paclobutrazol and Its Method of Application on The Growth of Pentas lanceolata Plants

Abstract

This study was carried out during the two successive seasons of 2013 and 2014 at Antoniades Research Branch, Horticulture Research Institute, A.R.C. Alexandria, Egypt . The experiment was carried out to investigate the effect of paclobutrazol ( PBZ) at the concentrations of ( 30,60,90 and120 mg/L) and its application method ( drench and spray ) on the growth, flowering and chemical composition of Pentas lanceolata, L. plants .The results showed that all the treatments caused a positive effect on the reduction of the vegetative growth of pentas plants and the treatment of 120 mg/L PBZ caused the highest significant reduction on most studied characters of vegetative growth . While there was insignificant effect after PBZ application at all concentrations on the flowering characteristics. For roots dry weight, the chlorophyll content and total carbohydrate content there was a significant increase after the application of PBZ at different concentrations. Drench application of PBZ was more effective than foliar application of in reduction of the most studied vegetative growth characters and increasing roots dry weight, the chlorophyll content and total carbohydrate content.