Response of Vegetative and Reproductive Parameters of Water Stressed Tuberose Plants to Vapor Ga rd (VG) and Kaolin Antitranspirants (AT)

Effects of different types of antitranpirants (ATs) on vegetative growth, flowering, marketable inflorescences, bulb production, mineral concentration, soluble sugars, and total carbohydrate concentration of tuberose (Polianthes tuberose L.) cv. Double plants, grown under the irrigation regimes of 100%, 80% and 60% of total evapotranspiration (ET) values, were investigated to select the suitable (AT) for conserving irrigation water, and with no detrimental effects on growth and production of tuberose plants grown in Al-Qassim region. Plant biomass, number of leaves, length and weight of marketable inflorescences and bulb yield were significantly reduced by water deficit, particularly at 60% (ET). But the flowering period was markedly shortened under stress conditions. Under water deficit (N, P, K, Ca) total carbohydrates and soluble sugars decreased in treated leaves as 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, relative t o the irrigation regime of 80 %( ET). The particle type (AT) Kaolin was more effective than the emulsion type (AT), Vapor Gard (VG), which might be attributed to its mechanism for reducing leaf temperature, transpiration rate, improvement of plant water status and maintaining biomass production of tuberose plants. Due to the superiority of Kaolin particle film in regulating plant performance and chemistry it is recommended for reducing water loss by plants in Al-Qassim region, Saudi Arabia. (author)