EFFECTS OF FOLIAR SPRAYS ON TURFGRASS OF AN EXTRACT OF PEAT AND KELP AMENDED WITH IRON

Under iron (Fe)-stress conditions, Fe has been applied to grass for co lor enhancement and growth improvement. In this way, the effects of th e application of a commercial product based on peat and seaweed extrac ts amended with Fe as a citrate-phosphate and vitamins were tested on a permanent grassland stressed in previous years by drought, weeds, an d human activity. Two applications of product in winter and in spring, were sprayed at two rates, one suggested by the manufacturer (13.5 mL of concentrated product/700 mL water) and a double dose (27 mL/700 mL water). Effects of the product on biomass production, color enhanceme nt, physical strength of the shoot and root systems, and mineral compo sition of the grass were evaluated. Results showed that immediately af ter both winter and summer applications of the product, a color enhanc ement measured by a chlorophyll meter was observed, and then this effe ct disappeared. Also a significant increase of physical strength of sh oot and root systems was observed after spring application. No signifi cant differences in foliage concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were observed be tween the control and treated plants. The most important effect of the product was an increase of Fe concentration in leaves, achieving norm al levels of Fe from slightly deficient levels. A slight decrease in m anganese (Mn) concentration due to a Fe/Mn antagonism was observed. Th e product showed a high capacity to supply Fe and to increase the phys ical strength of the plants.