Studies on the mineral nutrition of the rice plant: XVII. mineral requirements of the varieties IAC-164 and IAC-165

Abstract

Two upland rice varieties, IAC-164 and IAC-165 were grown in full strenght nº 2 Hoagland's solution untill their life cycle was completed. Dry matter production and both macro and micronutrient contents were then determined. Accumulation of macronutrients obeyed the following decreasing order: IAC-164 - K, N, Ca, Mg, P, and S; IAC-165 - N, K, Ca, P = Mg, and S. Exportation of macronutrients followed the same order for both varieties namely: N, K, P, Mg, Ca, and S. Percentwise P was the element exported in the grains in higher proportion. The requirement for micronutrients showed the following decreasing order: IAC-164 - Cl, Fe, Zn, Mn, Cu, B, and Mo; IAC-165 - Cl, Fe, Mn, Zn, Cu, B, and Mo. The extremely high Cl content was tentatively explained by luxury consumption. Both varieties presented the same trend in the exportation of micronutrients: Cl, Zn, Fe, Mn, Cu, B and Mo. Variety IAC-165 showed a higher efficiency of utilization of elements for yield formation, only P and Ca being exceptions.