Effects of Kaolin and Pinolene film-forming polymers on water relations and photosynthetic rate of tuberose (Polianthes tuberosa L.) plants under water deficit conditions.

Abstract: The effects of pinolene-base Vapor Gard (VG) emulsion type film and Kaolin (Surround WP) particle type film antitranspirants on stomatal behaviour, water status, carbon assimilation and transpiration rate of tuberose (Polianthes tuberosa) cv. Double plants, grown under irrigation regimes of 100, 80 and 60% of total evapotranspiration (ET) values, were studied to select the most suitable antitranspirant for conserving irrigation water, with no detrimental effects on growth and production of tuberose plants grown in arid regions. Severe water stress decreased the stomatal frequency and conductance (gs), leaf water potential ( Psi w), osmotic potential ( Psi pi ) and turgor potential ( Psi p), relative water content (RWC), chlorophyll content (chl), carbon assimilation rate (A) and transpiration rate (E). Both types of antitranspirants effectively enhanced the performance and physiological activities of water-stressed plants particularly, at the 80% ET, but they did not compensate for the negative effects caused