Influence of water regime on initial growth and essential oil of Eucalyptus globulus

Abstract

Understanding the water requirement of forest species in the seedling stage supports cost reduction by eliminating unnecessary irrigation in addition to providing higher productivity. This study was carried out to evaluate the effect of the water regime on initial growth, leaf production and content and chemical composition of the essential oil of Eucalyptus globulus , during the first 120 days of cultivation. The experiment employed a completely randomized design and was carried out at the Instituto de Ciências Agrárias da Universidade Federal de Minas Gerais (ICA/UFMG), Montes Claros, MG. Treatments consisted of six different water regimes (50%, 75%, 100%, 125%, 150% and 175% of the reference evapotranspiration - ETo) with four replicates. Plant growth was evaluated by measuring linear dimensions - height, stem diameter and number of leaves. The essential oil was extracted from fresh leaves by hydrodistillation in a Clevenger apparatus. The present study demonstrated that irrigation depths corresponding to 75% of the ETo are responsible for increased growth of E. globulus and increased dry matter production of leaves. The lowest irrigation levels were responsible for the greatest essential oil content. The essential oil was analyzed by gas chromatography-mass spectrometry (CG- MS), and eucalyptol (40.84% to 55.72%) was reported to be the major compound for all treatments. Compounds such as β-myrcene, α-Gurgujeno, Alloromadendreno, Varidiflorene appear under specific irrigation conditions.

Efeitos Do Déficit Hídrico No Cultivo De Mudas De Eucalipto

“…The treatments consisted of six irrigation levels (50%, 75%, 100%, 125%, 150% and 175% of the reference evapotranspiration -ETo) with four replications fully randomized. The results indicate that the seedlings of E. globulus grown under irrigation blade corresponding to 75% of ETo (blade O metabolismo primário e secundário de espécies florestais é influenciado pela disponibilidade hídrica (STAPE et al, 2010;QUEIROZ et al, 2017), sendo a fase de produção das mudas, a mais sensível para o seu fornecimento, uma vez que o suprimento adequado garante crescimento rápido e homogêneo (LOPES et al, 2007). Para o correto manejo e dimensionamento do sistema de irrigação, parâmetros como a evapotranspiração de referência (ETo), evapotranspiração da cultura (ETc) e o coeficiente da cultura (Kc) devem ser previamente determinados (CHAVES et al, 2005).…”

Irrigation frequency and vermiculite proportion in substrate for Eucalyptus grandis seedling

“…Water demand of eucalyptus seedlings varies abruptly according to local climate conditions and, therefore, it is important to emphasize the scope of this study. Silva et al (2015) irrigated seedlings from different eucalyptus hybrids in the summer of Viçosa, MG, Brazil, and found that the best daily irrigation depth was 11 mm, while Queiroz et al (2017) found a value of 4.5 mm for Montes Claros, MG, Brazil.…”

Desenvolvimento Inicial De Mudas De Eucalipto Sob Diferentes Lâminas De Irrigação

“…Esse resultado difere do encontrado por Queiroz et al (2017) Na segunda fase do experimento durante a rustificação (Tabela 6), mesmo reduzindo as doses de água, os tratamentos com aplicação de lâminas calculadas através da ETo, apresentaram ganho no número de folhas, sendo que o maior número de folhas foi encontrado para o manejo com 300% da ETo diferindo dos demais. Os tratamentos com aplicação de lâminas utilizando a tensão de água no substrato, sofreram uma desfolha muito grande, isso pode ter ocorrido devido ao aumento nas tensões no solo com acréscimo 1 kPa a cada semana, causando assim um déficit hídrico além do adequado para fins de rustificação, fazendo com que as mudas perdessem folhas, fato relatado por Lopes et al (2007) Irr.…”