Biomass production, B acumulation and Ca/B ratio in Eucalyptus under various conditions of water availability and B doses

• Autor(a) principal: Ramos, Sílvio Júnio
• Data de Publicação: 2016
• Outros Autores: Faquin, Valdemar, Ávila, Fabrício William, Ferreira, Rose Myrian Alves, Araújo, Josinaldo Lopes
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFLA
• Texto Completo: http://www.cerne.ufla.br/site/index.php/CERNE/article/view/903; http://repositorio.ufla.br/jspui/handle/1/14587
• topic: Micronutrient; Synergism; Water tension; Micronutriente; Sinergismo; Tensão hídrica

Soils destined for forest crops are often limiting with respect to boron (B) and in several eucalyptus crops boron deficiency has been found to be a common occurrence. The objective of this study is to evaluate biomass production, B accumulation and Ca/B ratio in eucalyptus cultivated under different conditions of soil, water availability and doses of B. To that end, an experiment was conducted using a completely randomized design with a 5 x 2 x 2 factorial arrangement consisting of five doses of B (0.00, 0.25, 0.75, 2.25 and 6.25 mg kg-1), two types of soil, namely a Dark Red Latosol (LE) and a Red-Yellow Latosol (LV), and two water tension levels (-0.033 and -0.010 MPa), with four replicates. After plants were grown, determinations were made of Ca and B contents as well as Ca/B ratios in different portions of the plants. Accumulation of B was obtained from the ratio of its contents to dry biomass in each plant portion. It was found that, under natural conditions, both Dark Red Latosol and Red-Yellow Latosol fail to meet the nutritional requirements for B in eucalyptus, potentially being limiting to that species. Overall, soil moisture influenced dry biomass production and accumulation of B only in the case of the more sandy texture soil (Red-Yellow Latosol), denoting that this factor is conditional on soil texture. Ca/B ratio results showed that application of B to the soil without a suitable supply of Ca can lead to an imbalance between these nutrients, with possible implications for plant growth and nutrition.