Caracterização morfofisiológica, bioquímica e anatômica do dendezeiro (Elaeis guineensis Jacq.) em função da disponibilidade hídrica e doses de silício
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Data
2022-05-29
Autores
Paixão, Jaquelyne Poliszuk Azevedo
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Universidade Estadual Paulista (Unesp)
Resumo
O dendezeiro representa uma das principais culturas produtoras de óleo no mundo. Por ser uma planta exótica, o dendezeiro deve ser estudado na sua ecofisiologia nas diversas condições em que é cultivado, pois o comportamento desta cultura no habitat influencia na quantidade de óleo produzido. Objetivou-se avaliar as respostas morfofisiológicas, bioquímicas e anatômicas, de plantas de Elaeis guineensis Jacq em função da disponibilidade hídrica e doses de Si. Utilizou-se o delineamento experimental inteiramente casualizado, no esquema fatorial 3 x 2 com 3 repetições, sendo os fatores: 3 doses de Silício (0, 200 e 400 mg L-1) e 2 níveis de água no solo, capacidade de campo (CC) e 1/3 da capacidade de campo (1/3 CC). O experimento foi realizado em dois ciclos de 6 meses, na qual as doses de Si, foram aplicadas mensalmente e as condições hídricas controladas em todo o período experimental. Foram avaliadas as características biométricas, os parâmetros fotossintéticos, os caracteres anatômicos e os teores nutricionais de plantas do dendezeiro. Em relação as características biométricas, os maiores valores foram obtidos nas plantas submetidas à CC em ambos os ciclos. No primeiro ciclo a fotossíntese aumentou nas plantas submetidas à CC e à dose de 400 mg L-1 de Si. Em 1/3 CC a dose de 200 mg L-1 foi a que proporcionou a obtenção dos maiores valores das variáveis fotossintéticas do dendezeiro. A fotossíntese diminuiu nas plantas com 1/3 CC, mas os teores de feofitina não diferiram indicando que o déficit hídrico não desencadeou o estresse severo nas plantas. Ao final do primeiro ciclo as plantas cultivadas na CC e na dose 200 mg L-1 de Si apresentaram maiores médias dos caracteres anatômicos (espessura da epiderme adaxial e abaxial, espessura do mesófilo homogêneo e espessura total) comparado às cultivadas na mesma condição hídrica e na dose 0 mg L-1de Si. No primeiro ciclo a dose 200 mg L-1 de Si proporcionou maior teor de K. e os teores de P e Mg foram maiores nas plantas submetidas a CC. No segundo ciclo pode-se verificar uma tendência diferente em relação a fotossíntese, na qual as plantas submetidas a 1/3 CC apresentaram maior capacidade fotossintética, indicando resistência do dendezeiro a esta condição. Ao final do segundo ciclo as plantas cultivadas a 1/3 da CC apresentaram teor de N maior comparado àquelas cultivadas a CC.
Oil palm represents one of the main oil-producing crops in the world. As an exotic plant, oil palm should be studied in its ecophysiology under the different conditions in which it is cultivated, as the behavior of this culture in the habitat influences the amount of oil produced. The objective was to evaluate the morphophysiological, biochemical and anatomical responses of Elaeis guineensis Jacq plants as a function of water availability and Si rates. A completely randomized design was used, in a 3 x 2 factorial scheme with 3 replications, the factors being: 3 rates of silicon (0, 200 and 400 mg L-1) and 2 levels of soil water, field capacity (DC) and 1/3 field capacity (1/3 DC). The experiment was carried out in two cycles of 6 months, in which the doses of Si were applied monthly and the water conditions were controlled throughout the experimental period. Biometric characteristics, photosynthetic parameters, anatomical characters and nutritional contents of oil palm plants were evaluated. Regarding the biometric characteristics, the highest values were obtained in plants submitted to CC in both cycles. In the first cycle, photosynthesis increased in plants submitted to CC and to the rate of 400 mg L-1 of Si. In 1/3 CC, the rate of 200 mg L-1 was the one that provided the highest values for the photosynthetic variables of oil palm. Photosynthesis decreased in plants with 1/3 CC, but pheophytin levels did not differ, indicating that water deficit did not trigger severe stress in plants. At the end of the first cycle, plants grown in CC and at a rate of 200 mg L-1 of Si showed higher means of anatomical characters (adaxial and abaxial epidermis thickness, homogeneous mesophyll thickness and total thickness) compared to those grown in the same hydric and at a rate of 0 mg L-1 of Si. In the first cycle, the dose of 200 mg L-1 of Si provided higher K content and the P and Mg contents were higher in plants submitted to CC. In the second cycle, a different tendency can be verified in relation to photosynthesis, in which plants submitted to 1/3 CC showed greater photosynthetic capacity, indicating oil palm resistance to this condition. At the end of the second cycle, the plants grown at 1/3 of the CC had higher N content compared to those grown at CC.
Oil palm represents one of the main oil-producing crops in the world. As an exotic plant, oil palm should be studied in its ecophysiology under the different conditions in which it is cultivated, as the behavior of this culture in the habitat influences the amount of oil produced. The objective was to evaluate the morphophysiological, biochemical and anatomical responses of Elaeis guineensis Jacq plants as a function of water availability and Si rates. A completely randomized design was used, in a 3 x 2 factorial scheme with 3 replications, the factors being: 3 rates of silicon (0, 200 and 400 mg L-1) and 2 levels of soil water, field capacity (DC) and 1/3 field capacity (1/3 DC). The experiment was carried out in two cycles of 6 months, in which the doses of Si were applied monthly and the water conditions were controlled throughout the experimental period. Biometric characteristics, photosynthetic parameters, anatomical characters and nutritional contents of oil palm plants were evaluated. Regarding the biometric characteristics, the highest values were obtained in plants submitted to CC in both cycles. In the first cycle, photosynthesis increased in plants submitted to CC and to the rate of 400 mg L-1 of Si. In 1/3 CC, the rate of 200 mg L-1 was the one that provided the highest values for the photosynthetic variables of oil palm. Photosynthesis decreased in plants with 1/3 CC, but pheophytin levels did not differ, indicating that water deficit did not trigger severe stress in plants. At the end of the first cycle, plants grown in CC and at a rate of 200 mg L-1 of Si showed higher means of anatomical characters (adaxial and abaxial epidermis thickness, homogeneous mesophyll thickness and total thickness) compared to those grown in the same hydric and at a rate of 0 mg L-1 of Si. In the first cycle, the dose of 200 mg L-1 of Si provided higher K content and the P and Mg contents were higher in plants submitted to CC. In the second cycle, a different tendency can be verified in relation to photosynthesis, in which plants submitted to 1/3 CC showed greater photosynthetic capacity, indicating oil palm resistance to this condition. At the end of the second cycle, the plants grown at 1/3 of the CC had higher N content compared to those grown at CC.
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Palavras-chave
Adubação silicatada, Estresse hídrico, Dendê, Silicate fertilization;, Water stress, Oil palm