Effects of Gibberellic Acid on Growth and Development of <I>Curcuma alismatifolia </I>Gagnep.

Abstract

Effects of gibberellic acid (GA₃) on growth and development of Curcuma alismatifolia Gagnep. were conducted. GA₃ at 0 100 300 and 500 mg/l were supplied twice at shoot emergence (4 weeks after planting) and 2 weeks thereafter. The results showed that  GA₃ at 300 and 500 mg/l gave the best results in terms of plant height of 101 and 97.38 cm, respectively but did not affect number of leaves per plant and number of shoot per cluster. GA₃ at 500 mg/l gave the longest scape of 87.13 cm which was 30 cm longer than control. But GA₃ at 500 mg/l also had effect on felling of stem plant. GA₃ application at 300 and 500 mg/l gave the longest number of day to flower 76 and 73 days respectively. This was more than control about 5-7 days. At flowering stage, nitrogen, potassium and phosphorus were analysed in upper ground and under ground parts. The result showed that GA₃ application affected the concentration and content of nitrogen and potassium but not for phosphorus. Nitrogen content in under ground parts was lowest (96.81 mg/plant) after GA₃ application at 500 mg/l. Application of GA₃ at 100 mg/l increased potassium content in under ground part. At harvest, GA₃ at 300 and 500 mg/l increased rhizome length.