INFLUENCE OF THE REPLANTING AGE ON YIELD AND GROWTH OF EUCALYPT CLONAL STANDS

ABSTRACT The growth of an eucalypt plantation should be monitored to identify factors that influence its development, helping in the decision-making process, aiming to reduce productivity losses. Thus, the objective of the present study was to evaluate the influence of the age of replanting on the yield and growth of eucalypt stands. The experiment was conducted in an area of CENIBRA S.A. Company, and established in a commercial plantation in August 2011. The application of herbicide and the ant control were performed in total area before planting. Seedlings of Eucalyptus urophylla × Eucalyptus grandis clones in 3.0 × 2.5 m spacing were used. Limestone (1,500 kg ha-1) was applied in total area before planting and 100 g plant-1 of NPK fertilizer (06-30-06) was applied immediately after planting. Four months after the installation of the experiment, 300 kg ha-1 of NPK (06-10-29) was applied. Treatments consisted of four dates of seedling replanting (0, 20, 40 and 80 days after planting) without complementary fertilization, and two treatments (replanting 40 and 80 days after planting) with supplementary fertilization (100g plant-1 NPK 06-30-06). The individual volume of replanting trees was 46.6% lower than of non-replanted ones. Treatments with complementary planting fertilization did not differ (p > 0.05) by the T-test. It is concluded that the longer the time between planting and replanting, the smaller the individual volume of the replanting trees and that the complementary fertilization in seedlings replanted does not favor their growth. RESUMO O crescimento de um plantio de eucalipto deve ser monitorado, para identificar fatores que influenciam o seu desenvolvimento, auxiliando na tomada de decisões para reduzir perdas de produtividade. Assim, o objetivo do presente estudo é avaliar a influência da época de realização de replantios sobre a produtividade e o crescimento de povoamentos de eucalipto. O experimento foi conduzido em uma área da CENIBRA S.A. e implantado em um plantio comercial em agosto de 2011. A aplicação de herbicida e o controle de formigas, em área total, foram realizados antes do plantio, com mudas clonais de Eucalyptus urophylla × Eucalyptus grandis no espaçamento 3,0 × 2,5 m. A calagem (1.500 kg ha-1) foi realizada em área total antes do plantio e 100 g planta-1 de fertilizante NPK (06-30-06), aplicado imediatamente após o plantio. Quatro meses após a instalação do experimento, 300 kg ha-1 de NPK (06-10-29) foi aplicado. Os tratament