Sources, dosages and manners of phosphorous application on phosphorous-zinc interaction in corn

In the present work, the objective was to evaluate the interaction of P-Zn in corn during two Successive cultivations, in a typical Red Argisol, loamy texture, in the area of the Savannah. The experimental layout was the one randomized blocks with four replications, in a 3x2x2+1 factorial outline, involving three doses of P2O5 ( 180, 360 and 540 kg ha(-1)), two sources (triple superphosphate-ST and Arad phosphate rock - FR), two application manners (casting on the total area and in the planting furrow, both in the first year) and a control (without P) as all additional treatment. One determined the dry matter weight of the aerial part and of grains, levels of K Zn and the relationship of P/Zn in the leaves and in the grains. The tenors of Zn were decreased with application of ST ill the seed furrow, reaching values said as deficient, in the first cultivation, without affecting, however, the corn produtivety. The tenors of P, Zn and P/Zn relationship in the grains presented themselves within the normal standard for corn. The interaction P-Zn at treatments with ST in the planting furrow, maybe due to previous manuring of Zn, was not sufficient to affect the yield grain of the corn.