EFFECT OF PLANT HORMONES ON THE GROWTH AND NUTRIENT UPTAKE OF MAIZE IN ACIDIC SOILS OF THE HUMID TROPICS

Abstract

An experiment was conducted in a greenhouse to investigate the availability of phosphate fertiliser in acidic soils, and to evaluate the effects of phosphorous and synthetic plant hormones on yield and nutrient uptake of maize (cv. Golda FAO-240). The soil was limed with 1.05 g of Ca(OH)2 and 12.2 g of CaSO4.2H2O 1.7 kg-1 soil according to Jensen Curve. Phosphorus was applied as Mono-ammonium dihydrogen phosphate at the rate of 0, 26 and 52 mg P 1.7 kg-1 soil by placed application using neutral compost as a buffering material. Benzyladenine (BA) and gibberellin (GA) were applied as exogenous plant hormones. Nitrogen, K, Mg, Cu, Mn, Zn, B and Mo were applied uniformly to all pots. In treatments that received P fertiliser without BA the dry matter yield and P uptake by plants were higher by 15.9 and 19.5%, respectively, compared to the results of P with BA. Similarly, in treatments that received P fertiliser without GA the dry matter yield and P uptake by plants were higher by 9 and 15.4%, respectively.