Crescimento e arquitetura radicial de plantas de eucalipto oriundas de mudas produzidas em blocos prensados e em tubetes, após o plantio

Abstract

The seedlings were produced according to two methodologies: pressed blocks and stiff plastic tubes. A mixture of decomposed sugar-cane bagasse (60%) and industrial sugar-cane plant residues (40%) were used as substrate. The blocks were made by pressing the humid substrate in metallic moulds with the dimensions of 60 x 40 x 20 cm (lenght, width and height) and pressure of 10 kgf/cm2 for 15 minutes. Under this load the blocks height was reduced to 10 cm. They were placed in wooden boxes with screen bottom. The stiff plastic tubes had circular section 12 cm high, with volume capacity of 50 cm3. The seeds were sown in the blocks 5 cm apart, by means of a spatula. At the end of nursey phase, the seedlings were planted the field. After 2, 6 and 10 months of planting, the height and the diameter at the ground level were evaluated. At the age of 10 months it was also evaluated the number of laterals root and deformatiom cofficient the three plants for treatment. Two months after planting, the plants originated from the pressed blocks showed growth highly signifficant in relation to those of the stiff plastic tubes. At 10 months, of age only Eucalyptus grandis seedlings showed significant difference concerning to height and diameter at the ground level between plants produced by pressed blocks and stiff plastic tubes. For the three species, the pressed blocks seedling showed higher number of lateral roots and smaller number of root deformation coefficents in comparision to the plants from the stiff tubes.