Acúmulo de matéria seca, absorção e exportação de micronutrientes em variedades de bananeira sob irrigação

Abstract

To estimate the demand of micronutrients for the banana plants (Musa spp.), it is essential to know the amounts of dry matter and micronutrients accumulated in the plant and exported by the bunch. The objective of this study was to evaluate the accumulation of dry matter and micronutrients by six banana varieties under irrigation. Plants of Grande Naine, Pacovan, Pacovan-Apodi, Prata-Anã, Terrinha and Gross Michel varieties grown in double rows, with a density equivalent to 1,666 plants per hectare were sampled. At harvest four plants of each variety were selected for sampling of mother-plant, which was divided into rhizome, pseudostem, petiole, leaf blade, stalk and fruits. The plant parts were weighed to determine the fresh weight of each part and a sample of about 700 g of each part was collected to determine dry weight and contents of micronutrients. The samples were washed quickly with tap water and later with distilled water and placed in a greenhouse for pre-drying and afterwards conditioned in paper bags were put in an oven of forced circulation of air for obtaining the dry matter and subsequent determination of the contents of B, Cu, Fe, Mn and Zn. The varieties Pacovan, Prata Anã e Pacovan Apodi accumulated greater amounts of dry matter and micronutrients, when compared to the varieties Grande Naine, Gross Michel e Terrinha, observing the following decreasing order of accumulation and export of micronutrients: Mn > Fe > B > Zn > Cu.