Utilização de água residuária na produção de mudas de flamboyant.

Abstract

Aiming to preserve the ecological equilibrium threatened by the great forestall devastation, it is badly needed the regeneration o f the devasted areas. Considering that a deficiency o f soil moisture usually is the most important limitation to the survival of tree seedlings, the increasing scarcity o f water resources has limited the forestall enterprises. Thus it has been observed a great interest of tree growers in new forest practices and techniques with the objective of attending the forestall products consume and commercialization. The use of residuary water on the tree production seems to be a promissory alternative due to the nutrient apport and because o f the preservation o f the water bodies. The lack o f information on seedlings production mainly with respect to the use o f residuary water for irrigation and soil subtracts justified the present study. The work was conducted on a greenhouse using the framboyant (Delonix regia) a forestall specie widely used on reforestation. It was used a randomized block design with four subtracts : soil, soil NPK fertilized, soil + organic compost and soil + biossolid , and two irrigation waters: normal and residuary water, arranged in a factorial form with three replicates, totalizing seven blocks and fifty six experimental units. After 25, 50 and 75 days it was sampled one block to measure the number o f leaves, height and diameter o f the stem and root length. At the end o f 100 days the four blocks left were analyzed statistically for the following indexes: number o f leaves, leaf area, height and diameter o f the stem, plant height, root length, and wet and dry weight o f the plant. It was observed that under laboratory conditions de germination depended on the treatment to which the seeds were submitted to break dormancy. At greenhouse conditions the germination depended mainly on the used subtract. The stem height and the root length were not affected by the treatments. The pretreated residuary water and the soil + biossolid subtract offered the higher plants and the greater dry weight o f the aerial part o f the plant. The soil + organic compost (humus) gave the greater dry weight o f the root.