EFFECTS OF NITROGEN SOURCE ON THE GROWTH AND NODULATION OF <em>ACACIA</em> <em>MANGIUM</em> IN AEROPONIC CULTURE

Abstract

WEBER, J., THAM, F. Y., GALIANA, A., PRIN, Y., DUCOUSSO, M. & LEE, S. K. 2007. Effects of nitrogen
source on the growth and nodulation of Acacia mangium in aeroponic culture. Effects of ammonium and
nitrate on growth and nodulation rates of Acacia mangium inoculated with Bradyrhizobium and grown in
aeroponic culture were studied. At concentrations of 13.6 and 4.9 mM, nitrate stimulated plant growth,
nitrogen uptake and total chlorophyll content compared with corresponding concentrations of ammonium,
which had a deleterious effect. On the other hand, nodulation was depressed with nitrate and totally
suppressed with ammonium at these two concentrations. However at 0.4 mM, ammonium actually stimulated
nodulation rates and resulted in robust plant growth comparable to that obtained with higher nitrate
concentrations. Ammonium nitrification was confirmed to be absent from measurements of the nutrient
solutions in aeroponic culture tanks.