Effect of Kaolin Film Particle Applications (Surround WP<sup>®</sup>) and Water Deficit on Physiological Characteristics in Rose Cut Plants (<i>Rose spp</i> L.)

Abstract

The effect of foliar applications of a kaolin clay particle film (Surround WP) on leaf temperature (Tlf), chlorophyll fluorescence (Fv/Fm), shoot length, production and water relations in well-irrigated and water-stressed rose cut plants (Rose spp) were studied during ten weeks. Plants were sprayed twice at first and fifth week after the experiment started with aqueous suspensions of Kaolin (Surround) at a dose of 5% (w/v). The interaction between Kaolin applications and water status did not showed significances. Water stress decreased the stomatal conductance (gs), leaf water content (LWC), shoot length and the number of marketable floral stems. Kaolin sprays did not affect on SPAD readings, chlorophyll fluorescence, gs, LWC and shoot length. Kaolin reduced leaf temperature by 2.5°C approximately at midday compared to plants non-sprayed with kaolin. These results show that kaolin foliar applications could be considered an useful tool at early growth stage in improving rose plant acclimation to high temperatures levels under greenhouse conditions in tropical regions.