Aspectos ecofisiológicos e de crescimento de Eucalyptus urograndis submetido à suplementação hídrica em plantios clonais

Abstract

The aim of this study was to evaluate the effect of water application on the physiological characteristics (net photosynthesis, stomatal conductance and transpiration) and dendrometric characteristics (diameter at breast height and height) of a clone of Eucalyptus grandis X Eucalyptus urophylla under field conditions and clarify the feasibility of this practice to accelerate plant growth for potential use in integration systems. The study consisted of two experiments, where the first on the evaluation of dendrometric characteristics was carried out in a randomized block design with four replications and four treatments (water levels). The second essay on the evaluation of the physiological characteristics was carried out in a completely randomized design with four treatments (water levels) and twelve replications. Each plots consisted of 56 plants and service area consisted of 18 plants. The treatments consisted of four levels of water (0, 9, 18 and 30 mm of water per plant), applied weekly from the beginning of the dry season until the beginning of the rainy season. In the dry season, the highest values of photosynthesis, stomatal conductance and transpiration were observed in the group of plants that received the highest water level. However, all physiological variables showed significantly better performance in the wet season. The behavior of dendrometric variables has slight influence depending on the levels of supplementation during the evaluated days. However, at the end of the experimental period, the characteristics were equal for all treatments evaluated. Thus, for clone studied, the water management adopted were not effiective in promoter greater plant growth and allow the anticipation of the entry of animals in integration systems.