Use of antitranspirants to improve water relations of Senecio cruentus DC. H̓ansaℓ̓

The antitranspirant chemicals Clear Spray and Vapor Card significantly increased stomatal diffusive resistance in cineraria by reducing transpiration on hot days. Foliar applications of the antitranspirant chemicals to both the upper and lower epidermal surfaces of the leaves were effective in reducing plant water stresses for a period of four weeks, after which time the benefits of the antitranspirant chemicals were greatly reduced. Clear Spray and Vapor Card did not have a significant effect on stomatal diffusive resistance when no water stresses existed on the plants. Leaf and ambient air temperatures significantly increased stomatal diffusive resistance and transpiration. Phytotoxic damage caused by Vapor Card was associated with high greenhouse temperatures. Transpiration losses measured gravimetrically over a four-day period confirmed that the benefits from the antitranspirant chemicals lasted only four weeks. Foliage sprayed with Clear Spray and Vapor Card was shiny due to the chemical film covering the entire leaf surfaces. As a result of this added benefit, the plants were more attractive than usual when in bloom.