Silício via fertirrigação alivia os estresses ocasionados pelo déficit hídrico em plantas de cana-de-açúcar cultivadas em diferentes solos
Carregando...
Arquivos
Data
2022-06-21
Autores
Sarah, Marcilene Machado dos Santos
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A ocorrência de restrição hídrica ao longo do cultivo cana-de-açúcar poderá refletir negativamente em sua produção, especialmente quando acometida nas fases iniciais de desenvolvimento. Somado a isso, a baixa disponibilidade de água poderá afetar a cultura plantada em diferentes localidades e classes de solo. Porém, o fornecimento de elementos benéficos como o silício (Si) durante o cultivo pode evitar danos celulares causados por estresses abióticos, além de estimular o crescimento da cultura. A partir disso, foram realizados três experimentos em estufa com mudas pré-brotadas (MPB) de cana-de-açúcar, que foram delineados em blocos casualizados, em esquema fatorial 2 x 2, com cinco repetições. O primeiro fator foi o regime hídrico em função da capacidade de retenção de água no solo (CRA): 35% e 70% da CRA, definidas como deficitária e não deficitária; e o segundo fator foi a concentrações de 0 mmol L-1de Si e 1,8 mmol L-1 de Si. Os tratamentos foram avaliados em diferentes classes de solos (Neossolo Quartzarênico, Latossolo Vermelho eutroférrico e Latossolo Vermelho distrófico). Os três experimentos foram avaliados tanto nos ciclos de cana-planta quanto na cana-soca. Além disso, com finalidade de validar os resultados obtidos em estufa, um quarto experimento foi realizado em campo, também com MPB, sendo delineado em faixas (Slip-block), em função da capacidade de retenção de água no solo (CRA): 70% (controle sem restrição hídrica), 35% (restrição hídrica) e 10% (semi-sequeiro); e duas condições de Si: ausência (0 mmol L-1 ) e presença (1,8 mmol L-1 ) de Si. Foram avaliados parâmetros fisiológicos, bioquímicos, biométricos, químicos e de qualidade tecnológica, com propósito de verificar as respostas da cultura e a viabilidade do fornecimento do Si via fertirrigação. E como resultado, observou-se que a restrição hídrica aumentou o estresse oxidativo devido a alta produção de ERO, levando a degradação de pigmentos fotossintéticos e redução da atividade de antioxidantes não enzimáticos. Além disso, o status hídrico das plantas foi prejudicado, resultando em menor desenvolvimento da cultura. Entretanto, o maior acúmulo de Si devido a seu fornecimento via fertirrigação aliviou os estresses ocasionados pela restrição hídrica, favorecendo o sistema fisiológicos e bioquímicos, diminuindo os danos causados pelo déficit hídrico. Logo, conclui-se que o fornecimento de Si é viável agronomicamente, podendo ser empregado em baixas quantidades em sistemas irrigados de cana-de-açúcar.
The occurrence of water restriction during sugarcane cultivation may reflect negatively on plant production, especially when it occurs in the early stages of development. Added to this, the low availability of water may affect the crop planted in different locations and soil classes. Furthermore, the supply of beneficial elements such as silicon (Si) during cultivation can prevent cell damage caused by abiotic stresses, in addition to stimulating the growth of the culture. From this, three experiments were carried out in a greenhouse with pre-sprouted sugarcane seedlings (MPB), which were designed in randomized blocks, in a 2 x 2 factorial scheme, with five replications. The first factor was the water regime as a function of the soil water regime (SWR): 35% and 70% of SWR, defined as deficit and non-deficit; and the second factor was at concentrations of 0 mmol L-1 of Si and 1.8 mmol L-1 of Si. The treatments were evaluated in different soil classes (Quartzipsamments, Eutrophic Red oxisols and Dystrophic Red oxisols). The three experiments were evaluated in both cane-plant and cane-ratoon cycles. In addition, in order to validate the results obtained in the greenhouse, a fourth experiment was carried out in the field, also with MPB, being designed in strips (Slip-block), depending on the soil water regime (SWR): 70% (control without water restriction), 35% (water restriction) and 10% (semi-irrigated); and two Si conditions: absence (0 mmol L-1 ) and presence (1.8 mmol L-1 ) of Si. Physiological, biochemical, biometric, chemical, and technological quality parameters were evaluated, to verify the responses of the culture and the feasibility of supplying Si via fertigation. As a result, it was observed that water restriction increased oxidative stress due to high ROS production, leading to photosynthetic pigment degradation and reduced non-enzymatic antioxidant activity. In addition, the water status of the plants was impaired, resulting in lower crop development. However, the greater accumulation of Si due to its supply via fertigation relieved the stresses caused by water restriction, favoring the physiological and biochemical system, reducing the damage caused by water deficit. Therefore, it can be concluded that the supply of Si is agronomically viable and can be used in low amounts in irrigated sugarcane systems.
The occurrence of water restriction during sugarcane cultivation may reflect negatively on plant production, especially when it occurs in the early stages of development. Added to this, the low availability of water may affect the crop planted in different locations and soil classes. Furthermore, the supply of beneficial elements such as silicon (Si) during cultivation can prevent cell damage caused by abiotic stresses, in addition to stimulating the growth of the culture. From this, three experiments were carried out in a greenhouse with pre-sprouted sugarcane seedlings (MPB), which were designed in randomized blocks, in a 2 x 2 factorial scheme, with five replications. The first factor was the water regime as a function of the soil water regime (SWR): 35% and 70% of SWR, defined as deficit and non-deficit; and the second factor was at concentrations of 0 mmol L-1 of Si and 1.8 mmol L-1 of Si. The treatments were evaluated in different soil classes (Quartzipsamments, Eutrophic Red oxisols and Dystrophic Red oxisols). The three experiments were evaluated in both cane-plant and cane-ratoon cycles. In addition, in order to validate the results obtained in the greenhouse, a fourth experiment was carried out in the field, also with MPB, being designed in strips (Slip-block), depending on the soil water regime (SWR): 70% (control without water restriction), 35% (water restriction) and 10% (semi-irrigated); and two Si conditions: absence (0 mmol L-1 ) and presence (1.8 mmol L-1 ) of Si. Physiological, biochemical, biometric, chemical, and technological quality parameters were evaluated, to verify the responses of the culture and the feasibility of supplying Si via fertigation. As a result, it was observed that water restriction increased oxidative stress due to high ROS production, leading to photosynthetic pigment degradation and reduced non-enzymatic antioxidant activity. In addition, the water status of the plants was impaired, resulting in lower crop development. However, the greater accumulation of Si due to its supply via fertigation relieved the stresses caused by water restriction, favoring the physiological and biochemical system, reducing the damage caused by water deficit. Therefore, it can be concluded that the supply of Si is agronomically viable and can be used in low amounts in irrigated sugarcane systems.
Descrição
Palavras-chave
Elemento benéfico, Estresse abiótico, Saccharum officinarum, Si, Cana-de-açúcar cultivo