Uso de bioestimulantes em feijoeiro cultivado sob deficiência hídrica
Data
2019-05-30
Autores
Galvão, Ícaro Monteiro
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A deficiência hídrica (DH) constitui um dos graves problemas para agricultura resultando em perdas de produção. O entendimento do comportamento das culturas frente a esta condição se torna de grande importância para auxiliar no manejo. O feijoeiro é uma planta bastante sensível aos efeitos da deficiência hídrica, especialmente se a mesma for imposta nas fases reprodutivas, sendo observadas alterações principalmente de ordem morfológica, fisiológica, bioquímica, que culminam em redução na produção. A utilização de bioestimulantes tem se destacado por atuarem como promotores de crescimento vegetal e apresentar capacidade de atenuar os impactos da DH nas plantas. O objetivo deste trabalho foi avaliar o comportamento morfológico, fisiológico, bioquímico e produtivo do feijoeiro submetido a deficiência hídrica no solo e o potencial de mitigação dessa condição pela inoculação de bioestimulantes a base de bactérias promotoras de crescimento, Bacillus amyloliquefaciens BV 03 e a associação com extratos de algas Ascophyllum nodosum. O ensaio foi conduzido em estufa agrícola em Botucatu-SP com feijoeiro comum cv. IAC Imperador, disposto em esquema parcela subdivididas em blocos casualisados e 4 repetições. Os tratamentos nas parcelas foram as lâminas de irrigação (10 kPa - Controle e 40 kPa - DH moderada) e nas subparcelas os bioestimulantes via tratamento de sementes (B1- controle; B2- Bacillus amyloliquefaciens BV; B3- Bacillus amyloliquefaciens BV 03 + extrato de algas- Ascophyllum nodosum). A irrigação foi por gotejamento e o monitoramento da umidade do solo foi feita por tensiometria. As variáveis analisadas foram diâmetro do caule; número de folhas; área foliar, biomassa seca das folhas, caule, raiz e total; comprimento, diâmetro e volume radicular; conteúdo relativo de água (CRA); teor de pigmentos foliares; trocas gasosas; proteínas solúveis totais; teor de L-prolina e atividade específica da enzima superóxido dismutase (SOD) e os parâmetros de produção. O feijoeiro foi afetado significativamente com a imposição da DH com reduções no crescimento, acumulo de biomassa e produção. Como mecanismo de resposta ao estresse o feijoeiro apresentou aumento no CRA e nos teores de prolina e SOD. Os bioestimulantes promoveram incremento na atividade fotossintética apenas em plantas com lâmina de irrigação controle (10 kPa). Nas demais avaliações e variáveis não foram observados resultados significativos em função da aplicação de bioestimulantes. A hipótese do trabalho não foi confirmada, uma vez que os tratamentos com bioestimulantes nas condições do presente estudo não foram eficientes em mitigar os efeitos da deficiência hídrica moderada em feijoeiro.
Water deficiency (WD) is one of the serious problems for agriculture, resulting in production losses. The understanding of the behavior of the crops in front of this condition becomes of great importance to assist in the handling. The bean is a plant very sensitive to the effects of water deficiency, especially if it is imposed in the reproductive phases, being observed changes mainly of morphological, physiological, biochemical, that culminate in reduction in the production. The use of biostimulant has been outstanding because they act as promoters of plant growth and have the ability to mitigate the impacts of water deficiency on plants. The objective of this work was to evaluate the morphological, physiological, biochemical and productive behavior of common bean submitted to soil water deficiency and the potential of mitigation of this condition by the inoculation of biostimulants based on growth promoting bacteria, Bacillus amyloliquefaciens BV 03 and the association with extracts of algae Ascophyllum nodosum. The experiment was conducted in an agricultural greenhouse in Botucatu-SP with common bean cv. IAC Imperador, arranged in plot scheme subdivided into randomized blocks and 4 repetitions. The treatments in the plots were applied to the irrigation levels (10 kPa - Control and 40 kPa – moderate WD) and in the subplots the biostimulants via seed treatment (B1- control; B2- Bacillus amyloliquefaciens BV; B3- Bacillus amyloliquefaciens BV 03 + extract of algae- Ascophyllum nodosum). The irrigation was by drip irrigation and soil moisture monitoring was done by tensiometry. The analyzed variables were stem diameter; number of leaves; leaf área; leaf dry biomass, stem dry biomass, root dry biomass and total dry biomass; length, diameter and root volume; relative water content (RWC); leaf pigment content; gas exchange; total soluble proteins; L-proline content and specific activity of the enzyme superoxide dismutase (SOD) and production parameters. The bean was significantly affected by the imposition of WD with reductions in growth, biomass accumulation and yield. As a mechanism of stress response the common bean increased in the RWC and in the contents of proline and SOD. Biostimulants promoted an increase in photosynthetic activity only in plants with a control irrigation levels (10 kPa). In the other evaluations and variables, no significant results were observed due to the application of biostimulants. The hypothesis of the work was not confirmed, since the treatments with biostimulants under the conditions of the present study were not efficient to mitigate the effects of moderate water deficiency in common bean.
Water deficiency (WD) is one of the serious problems for agriculture, resulting in production losses. The understanding of the behavior of the crops in front of this condition becomes of great importance to assist in the handling. The bean is a plant very sensitive to the effects of water deficiency, especially if it is imposed in the reproductive phases, being observed changes mainly of morphological, physiological, biochemical, that culminate in reduction in the production. The use of biostimulant has been outstanding because they act as promoters of plant growth and have the ability to mitigate the impacts of water deficiency on plants. The objective of this work was to evaluate the morphological, physiological, biochemical and productive behavior of common bean submitted to soil water deficiency and the potential of mitigation of this condition by the inoculation of biostimulants based on growth promoting bacteria, Bacillus amyloliquefaciens BV 03 and the association with extracts of algae Ascophyllum nodosum. The experiment was conducted in an agricultural greenhouse in Botucatu-SP with common bean cv. IAC Imperador, arranged in plot scheme subdivided into randomized blocks and 4 repetitions. The treatments in the plots were applied to the irrigation levels (10 kPa - Control and 40 kPa – moderate WD) and in the subplots the biostimulants via seed treatment (B1- control; B2- Bacillus amyloliquefaciens BV; B3- Bacillus amyloliquefaciens BV 03 + extract of algae- Ascophyllum nodosum). The irrigation was by drip irrigation and soil moisture monitoring was done by tensiometry. The analyzed variables were stem diameter; number of leaves; leaf área; leaf dry biomass, stem dry biomass, root dry biomass and total dry biomass; length, diameter and root volume; relative water content (RWC); leaf pigment content; gas exchange; total soluble proteins; L-proline content and specific activity of the enzyme superoxide dismutase (SOD) and production parameters. The bean was significantly affected by the imposition of WD with reductions in growth, biomass accumulation and yield. As a mechanism of stress response the common bean increased in the RWC and in the contents of proline and SOD. Biostimulants promoted an increase in photosynthetic activity only in plants with a control irrigation levels (10 kPa). In the other evaluations and variables, no significant results were observed due to the application of biostimulants. The hypothesis of the work was not confirmed, since the treatments with biostimulants under the conditions of the present study were not efficient to mitigate the effects of moderate water deficiency in common bean.
Descrição
Palavras-chave
Phaseolus vulgaris L., Estresse por seca, Bactérias promotoras de crescimento, Metabolismo antioxidante, Manejo da irrigação