Ecofisiologia de mudas de Bauhinia forficata Link em resposta a supressão de rega e posterior reirrigação

• Autor(a) principal: Nascimento, José Wellington Santos do
• Data de Publicação: 2020
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal de Alagoas (UFAL)
• Texto Completo: http://www.repositorio.ufal.br/handle/riufal/7236
• topic: Pata de vaca; Estresse hídrico; Espécies florestais; Water stress; Seedlings of forest species; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA

Water deficit is an environmental factor extremely harmful to the plant life, where they respond to disorders caused by this factor through morphophysiological changes with a strategy to ensure their adaptability and survival in drought conditions. Knowledge about plants responses allows to understand their behave in drought situations. Therefore, this paper aimed to evaluate the ecophysiology of Bauhinia forficata Link seedlings in response to irrigation suspension and subsequent re-irrigation. Thereunto, an experiment was conducted in the greenhouse at the Production Technology Laboratory (seedling production sector) at the Federal University of Alagoas, on Engineering and Agrarian Sciences Center (CECA). The experimental design was completely randomized, consisting of three treatments (Control - irrigated daily, Irrigation suppression and Reirrigated) and two evaluation periods [when the lowest value of the maximum quantum yield of photosystem II (PSII) of the irrigation suppression treatment, obtained by the Fv / Fm ratio (occurred on the 8th day after the differentiation of the treatments), and after finding the normality of the Fv / Fm ratio of the re- irrigation treatment (occurred on the 2nd day after the re-irrigation of the SR treatment)] with ten repetitions. Due to lower value of Fv / Fm ratio, five repetitions of each treatment (C and SR) were subjected to assessment of the behavior and physiological parameters and later, the experiment was disassembled. The remaining plants (five repetitions of treatment C and Five repetitions of treatment SR) were re-irrigated maintaining the irrigation until the end of the experiment, in which the plants of treatment SR formed the treatment R. The maximum and effective quantum yield (Yield) and the SPAD index were executed daily on the third fully expanded leaf at the plant top. The plant height, number of leaves and stem diameter were evaluated weekly. By the experiment end, were evaluated root length, dry biomass production and allocation on leaves, stem, roots and total, relative water content and photosynthetic pigments (chlorophyll a, b, carotenoids and total chlorophyll). Based on results, it was concluded that after 8 days of water stress, Bauhinia forficata seedlings are able to their metabolism reestablishment and to withstand up under water stress without compromising your metabolism. However, they can be drastically affected by prolonging the intensity and time of exposure to stress.