Journal of Applied Horticulture. 2005: 7(2): 72-78

Response of vegetative and reproductive parameters of water stressed tuberose (Polianthes tuberosa L.) plants to Vapor Gard and Kaolin antitranspirants

Al Humaid, A I; Moftah, A E

College of Agriculture and Veterinary Medicine (PO Box: 1482), King Saud University, Al-Qassim Branch, Saudi Arabia.

The effects of different types of antitranspirants (ATs) on vegetative growth, flowering, marketable inflorescences, bulb production, elemental content, soluble sugars, and total carbohydrate concentrations of tuberose (Polianthes tuberosa cv. "Double"), grown under the irrigation regimes of 100, 80 and 60% of total evapo-transpiration (ET) value, were investigated. Plant biomass, number of leaves, length and weight of marketable inflorescences and bulb yield were significantly reduced by water deficit, particularly at 60% ET. The flowering period was markedly shortened under stress conditions. Under water deficit, N, P, K, Ca and total carbohydrates decreased, while soluble sugars increased in treated leaves compared to the control plants. Both types of ATs effectively enhanced plant performance, flower formation, bulb production, nutrient uptake and carbohydrate synthesis at the 80% ET treatment. The particle type AT, Kaolin, was more effective than the emulsion type AT, Vapour Gard (VG), due to its mechanism for reducing leaf temperature, one of the vital factors limiting plant physiology and function under arid and semi-arid conditions. Due to the superiority of Kaolin particle film in regulating plant performance, it is recommended for reducing water loss by plants in arid and semi-arid regions.