Physiological responses of Eucalyptus urophylla young plants treated with biostimulant under water deficit/Respostas fisiologicas de plantas jovens de Eucalyptus urophylla tratadas com bioestimulante sob deficit hidrico

• Published in: Ciência florestal 2019-07, Vol.29 (3), p.1072
• Main Authors: Santos, Rayka Kristian Alves, Cairo, Paulo Araquém Ramos, Barbosa, Romário Pereira, de Lacerda, Janderson Jesus, da Neto, Caio Silva Mafra, de Macedo, Theilon Henrique Jesus
• Format: Article
• Language: Spanish
• Subjects: Cytokinins; Droughts; Gibberellins; Growth regulators; Photosynthesis; Plant biochemistry; Plant hormones; Saturated fatty acids; Soil moisture; Water; Water resources
• ISSN: 1980-5098; 1980-5098
• DOI: 10.5902/1980509826206

Biostimulants consist of a mixture of growth regulators that, when they are sprayed on plants, act on hormonal balance, enhancing its development. Stimulate[R] is a biostimulant composed by indole butyric acid (0.005%), kinetin (0.009%) and gibberellic acid (0.005%) which promotes root growth, improves water and nutrients uptake, and helps restore plant hormonal balance. This research was based on the hypothesis that Stimulate[R] spraying can be an alternate way to mitigate negative effects of soil water-limiting on plant growth. The experimental work was performed in greenhouse and aimed to evaluate physiological responses of young plants of Eucalyptus urophylla sprayed with different Stimulate[R] concentrations and submitted to the following irrigation regimes: full, partial and no irrigation. Leaf water potential, relative water content, net photosynthesis, plant height and main root length were measured. Under water-limited conditions, plants sprayed with Stimulate[R] showed higher net photosynthesis and relative water content had a less decrease, due to osmotic adjustment. Spraying with Stimulate[R] also provided greater plant height and longer main root length in plants under water deficit. We conclude that the use of Stimulate[R] can be a viable option to mitigate negative water stress physiological effects in young plants of Eucalyptus urophylla, helping to partially maintain the plant growth under water-limited conditions. Keywords: Woody plants; Plant growth regulators; Drought; Water stress Os bioestimulantes consistem em uma mistura de reguladores de crescimento que, quando aplicados nas plantas, atuam no equilíbrio hormonal, melhorando seu desenvolvimento. Stimulate[R] é um bioestimulante composto por ácido indolbutírico (0,005%), cinetina (0,009%) e ácido giberélico (0,005%), que promove o crescimento das raízes, melhora a absorção de água e nutrientes e ajuda a restaurar o equilíbrio hormonal das plantas. Esta pesquisa foi baseada na hipótese de que a pulverização com Stimulate[R] pode ser uma forma alternativa de mitigar os efeitos negativos da limitação da água no solo para o crescimento das plantas. O trabalho experimental foi realizado em casa de vegetação e objetivou avaliar respostas fisiológicas de plantas jovens de Eucalyptus urophylla pulverizadas com diferentes concentrações de Stimulate[R] e submetidas aos seguintes regimes de irrigação: total, parcial e sem irrigação. Foram mensurados o potencial hídrico foliar, o teor relativo d