Effect of artificial leaf coatings on foliar chloride uptake during sprinkler irrigation

Abstract

Silicone and latex coatings applied to leaves have been used by other workers for the purpose of reducing transpiration of plants. The use of similar leaf coatings was studied by the authors for the purpose of reducing foliar chloride uptake from brackish water used for sprinkler irrigation. Significant reductions in foliar chloride uptake during sprinkling with NaCI solution were obtained by coating citrus leaves with acrylic polymer latex. The use of silicones to reduce foliar chloride uptake was not successful.Filters having a maximum pore size of 0.20 microns were impregnated with a range of concentrations of latex material. The diffusion resistance of these impregnated filters to CO 2 , O 2 , and water vapors was studied. Concentrations of the impregnating emulsion increasing from 10 to 25 per cent caused a relatively small increase in diffusion resistance for CO 2 and O 2 , but the use of 50 and 75 per cent emulsions caused a marked increase in diffusion resistance of the filter to these two gases.

Effect and Mode of Action of Latex and Silicone Coatings on Shoot Growth and Water Use by Citrus1

“…However, as shown elsewhere (7), latex emulsions are capable of forming continuous film across 250,u. diameter pores in aluminum foiL In that study, it was proposed that film could therefore form across the openings of the stomatal pits in sweet ora?ge.…”

“…Waggoner (10) has emphasized the importance of the efficiency of coating which he believes accounts for some apparent anomalies in published work. Efficiency of coating by latices has also been used by Gale and Poljakoff-Mayber (5) to explain effects of coating on photosynthesis, and by Malcom et al (7) to explain differences in foliar chloride uptake by latex coated plants. It is clear that the possibilities for using an antitranspirant to good effect in any given situation are complex.…”

“…T HE use of silicone and latex coatings applied to leaves to reduce foliar chloride uptake has been discussed elsewhere (6,7). Both silicones and latices have been used in attempts by other workers to reduce transpiration by plants.…”

“…The author has coated aluminum foil with AC-34 acrylic polymer 3 at 10% (v jv) with 1.3% (v jv) surfactant.4 Surfactant concentrations of this order have often been found necessary to give spreading of emulsion on citrus (7). By weighing and measuring the area of the film, the mean thickness was calculated to be 0.4,u.…”

Residue Reviews / Rückstands-Berichte

“…Most effective, as measured by permanency of the film and its ability to hold incorporated sand, were certain of the acrylic-based emulsions. With a somewhat different objective in mind, MALCOLM et al (1968) evaluated different leaf coatings for their ability to reduce uptake of chloride from brackish water used for sprinkler irrigation. Significant reductions in foliar uptake of chloride occurred during sprinkling with a sodium chloride solution when leaves were coated with acrylic polymer latex.…”