DETERMINAÇÃO DA MÁXIMA CAPACIDADE DE RETENÇÃO DE ÁGUA NO SUBSTRATO PARA PRODUÇÃO DE MUDAS DE EUCALIPTO EM VIVEIRO

The scarcity of information regarding water consumption of seedlings of forest species often complicates the planning of irrigation in commercial nurseries, often leading the adoption of inefficient management measures, causing loss in the quality of seedlings. Thus, this study sought to investigate the capacity of water retention in the substrate in which the eucalyptus seedlings can be submitted and determine the crop coefficient (Kc) for the hybrid clone of E. urophylla x E . grandis. The study was conducted in a greenhouse located in the experimental area of the Post-Graduation of Forest Sciences bound to the Center for Agrarian Sciences, Federal University of Espírito Santo in the city of Alegre, ES, built in a completely randomized design with five treatments of water availability in the substrate (90, 80, 70, 60 and 50% of MCRA) and four replications. According to the results, it was found that water availability in the substrate MCRA of the 70% can be used for the production of minicutting, without affecting standards of growth and quality. The Kc for eucalyptus seedlings in nursery conditions was 1.25.A escassez de informações referentes ao consumo hídrico de mudas de espécies florestais freqüentemente dificulta o planejamento da irrigação em viveiros comerciais, levando muitas vezes, a adoção de medidas ineficientes de manejo, provocando perda no padrão de qualidade das mudas. Dessa forma, procurou-se neste trabalho investigar a máxima capacidade de retenção de água (MCRA) no substrato em que as mudas de eucalipto podem ser submetidas e determinar o coeficiente de cultivo (Kc) para o clone híbrido de E. urophylla x E. grandis. O estudo foi realizado em casa de vegetação, localizada na área experimental do Programa de Pós-Graduação em Ciências Florestais vinculado ao Centro de Ciências Agrárias da Universidade Federal do Espírito Santo (CCA-UFES) no município de Alegre, ES, montado num delineamento inteiramente casualizado, com cinco tratamentos de disponibilidade hídrica no substrato (90, 80, 70, 60 e 50% da MCRA), com quatro repetições. De acordo com os resultados obtidos, verificou-se que a disponibilidade hídrica no substrato de 70% da MCRA pode ser utilizada para a produção de mudas clonais de eucalipto, sem afetar o crescimento e o padrão de qualidade. O Kc estimado para as mudas de eucalipto em condições de viveiro foi de 1,25. AbstractDetermination of maximum capacity of water retention in substrate for production plants in Eucalyptus nursery. The scarcity of information regarding water consumption of seedlings of forest species often complicates the planning of irrigation in commercial nurseries, often leading the adoption of inefficient management measures, causing loss in the quality of seedlings. Thus, this study sought to investigate the capacity of water retention in the substrate in which the eucalyptus seedlings can be submitted and determine the crop coefficient (Kc) for the hybrid clone of E. urophylla x E . grandis. The study was conducted in a greenhouse located in the experimental area of the Post-Graduation of Forest Sciences bound to the Center for Agrarian Sciences, Federal University of Espírito Santo in the city of Alegre, ES, built in a completely randomized design with five treatments of water availability in the substrate (90, 80, 70, 60 and 50% of MCRA) and four replications. According to the results, it was found that water availability in the substrate MCRA of the 70% can be used for the production of minicutting, without affecting standards of growth and quality. The Kc for eucalyptus seedlings in nursery conditions was 1.25.Keywords: Coefficient of cultivation; irrigation management; Eucalyptus urophylla x E. grandis