Efeito do fosfato de Araxá, calcário e gesso em mudas de seringueira.

Abstract

The experiment was installed under greenhouse conditions in the Department ofAgriculture of the Escola Superior de Agricultura de Lavras- (ESAL), Lavras, MG, Brazil, to evaluate the effects of combinations of "AraxA" phosphate rock, dolomitic lime and gypsum on the growth and macronutrient uptake by rubbertree seedlings {Hevea sp.). Top-layersamples ofa very clayey, Epiallic Dark Red Latosol "Cerrado" phase were used. The experimental design was in randomized blocks with 5 2 factorial (5 phosphate levels: 5,50, 100, 150,200 kg/ha P205 with 5 combinations of lime and gypsum being: no gypsum and no lime, 100% lime, 33% lime + 67% gypsum, 67% lime + 33% gypsum and 100% gypsum. The seedlings were allowed to grow for 12 months and them plant height, diameter, dry matter, concentrations of K, N, Ca, Mg and S on the leaves, Al concentrations on the roots and P accumulation on the leaves and total dry matter were determined. Analyses of variance and regression/correlations were performed on the data allowing the following conclusions: none of the lime and gypsum combinations affected plant height of diameter; combinations of lime and gypsum had no effect on dry matter yield, but they were superior to lime or gypsum applied separately.