Summer condition promoted growth, development, and carbohydrate content in sacred lotus (Nelumbo nucifera Gaertn.)

Abstract

© 2020 International Society for Horticultural Science. All rights reserved. Sacred lotus (Nelumbo nucifera Gaertn.) is one of the most important flowering crops in Thailand, commonly used as cut-flower for cultural purposes. An important factor to control flowering in this plant could be the availability of a food reserve, as carbohydrate metabolism was affected by changes in environmental conditions. The experiment was conducted in CRD over 6 months of different tropical environmental conditions in Thailand, which can be divided into two seasonal conditions: Summer (April to June) and the rainy season (July to September). It was found that the summer condition stimulated vegetative growth of the plant with more leaves, but the rainy season gave longer stolon and better flowering percentage. Summer condition induced more dry weight distribution to the flower than another condition; while the rainy season distributed the largest dry weight proportion to the stolon. Rainy season condition gave higher reducing sugar (RS) content in the stolon than the summer condition; while, in other organs there were no significant differences. In contrast, higher total non-structural carbohydrate (TNC) content in all organs was found in the summer months. The RS content in the flower was not different between summer and rainy seasons, but the TNC content in the flower was found to be higher in summer. The highest RS and TNC contents were distributed to the stolon in all 6 months of the growing period, except in April, when the highest RS and TNC were distributed to the flower. Nevertheless, better growth, development, and carbohydrate content in summer condition, could not promote better flowering in sacred lotus.