NUTRIENT ACCUMULATION IN RICE PLANTS AS A FUNCTION OF SOURCES AND LEVELS OF ZINC APPLIED TO SEEDS

Abstract

Although zinc is widely used in agriculture, special attention is required when studying its interactions with other nutrients. The objective of this research was to evaluate the effects of zinc doses and sources applied to rice (cv. Caiapó) seeds on the nutrient contents and accumulation in the initial growth phase. The experiment was conducted in a greenhouse, at Unesp/ Jaboticabal Campus - São Paulo, Brazil (21º15’22’’S, 48º18’58’’W, altitude 575 m), from February to March 2005. The experimental design was the entirely randomized one, with three replications. The treatments were five doses of Zn: 0 g kg^-1, 1 g kg^-1, 2 g kg^-1, 4 g kg^-1, and 8 g kg^-1 of seeds; and two sources of zinc - sulphate and oxide. The increase of zinc sulphate doses promoted a higher accumulation of S, Cu, Fe, and Mn in the shoots, and of N, P, K, Ca, Mg, S, B, Cu, Fe, and Mn in rice roots. However, it promoted a smaller accumulation of N, K, and B in the shoots. The increase of zinc oxide doses promoted a higher accumulation of K, Mg, S, Cu, and Mn in the shoots, and of N, Ca, B, Cu, and Mn in the roots. However, it promoted a smaller accumulation of N, Ca, B, and Fe in the shoots, and of P in the roots.

KEY-WORDS: Fertilization; plant nutrition; Oryza sativa L.; Zn; micronutrients.