Fisiologia e bioquímica do tomateiro submetido à irrigação salina parcial do sistema radicular
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Data
2016-02-25
Autores
Alves, Rita de Cássia [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O tomateiro é uma das hortaliças mais cultivadas em ambiente protegido, destacando-se entre as hortaliças melhor adaptadas a esse sistema de cultivo. A produção e qualidade dos frutos estão diretamente relacionadas com a qualidade da água utilizada e o manejo adequado da irrigação. Para propor estratégias de manejo no uso de água salina na irrigação de tomateiro, o presente estudo teve como objetivo avaliar o crescimento, desenvolvimento, rendimento; qualidade e respostas antioxidantes do tomateiro cultivado sob estresse salino parcial do sistema radicular. O experimento foi conduzido em ambiente protegido na Universidade Federal Rural do Semi-Árido (UFERSA), em Mossoró, RN, Brasil. O delineamento estatístico utilizado foi o inteiramente casualizado, com seis tratamentos e quatro repetições, totalizando 24 unidades experimentais. Os tratamentos consistiram de seis manejos de irrigação utilizando águas de baixa e alta salinidade (S1-0,5 e S2-5,0 dS m-1), com ou sem divisão do sistema radicular. Para os tratamentos T1, T2 e T3 não houve divisão do sistema radicular, sendo que para tratamentos T4*, T5* e T6*, foi adotado o sistema de divisão das raízes. O número de folhas, área foliar, altura de planta, diâmetro de caule e partição de fotoassimilados (massa seca de folha, caule, raiz, fruto e total) foram os parâmetros de crescimento determinados. Diâmetro transversal, diâmetro longitudinal, número de frutos por planta, massa fresca média de fruto, produção, pH, Firmeza de polpa, teor de sólidos solúveis, acidez titulável, vitamina C coloração de frutos, licopeno e β-caroteno foram determinados como parâmetros para a avaliação do rendimento e qualidade dos frutos enquanto as respostas antioxidantes foram utilizadas para avaliação do estresse oxidativo. De acordo com os resultados, não foi observado efeito deletério da salinidade sobre o crescimento e partição de fotoassimilados, uma vez que as respostas observadas em todos os tratamentos foram semelhantes ao tratamento T1 (controle). Os melhores resultados de rendimento e qualidade foram observados nos tratamentos T4* e T5*. O PRSI não influenciou nas respostas das enzimas antioxidantes nas folhas, frutos e raízes. No entanto, a atividade da GR foi influenciada negativamente pelo uso do sistema de irrigação salina parcial do sistema radicular (ISPSR). O sistema ISPSR, quando manejado de forma adequada, mostra-se como uma alternativa viável para redução dos efeitos deletérios provocados pelo estresse salino no híbrido de tomateiro Supera F1.
Tomato is one of vegetables most cultivated in greenhouses, standing out among the plants adapted to this cropping system. The production and fruit quality are directly related to the quality of water used for irrigation and its appropriate management. In order to propose management strategies for use of saline water irrigation in tomato crop production, the present study aimed to evaluate the growth and development of plants, yield and quality, and antioxidant responses of tomato cultivated under a partial salt stress of the root system. The experiment was carried out in a greenhouse at the Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró, RN, Brazil. The experimental design was completely randomized, with six treatments and four replicates, totaling 24 experimental units. The treatments consisted of six different irrigation managements using low and high saline water (S1-0.5 and S2-5.0 dS m-1), applied with or without the partial root-zone saline irrigation (PRSI). For the treatments T1, T2 and T3, the PRSI was not applied, whilst T4*, T5* and T6* treatments were under the PRSI. The number of leaves, leaf area, plant height, stem diameter and dry weight of leaf, stem, root and, fruit were determined as plant growth parameters. Cross diameter, lengthwise diameter, number of fruits per plant, mass average fresh fruit, yield, pH, pulp firmness, soluble solids content, titratable acidity, vitamin C, color relation (a*/b*), lycopene and β-carotene were determined as parameters for the fruit yield and quality evaluation, while antioxidante enzymes were used for oxidative stress evaluation. According to results, it was not observed deleterious effect of salinity on plant growth and assimilates, since that responses observed in all treatments were similar to T1 treatment (control). The best results of yield and quality responses were observed in T4* and T5* treatments. About antioxidants responses, the PRSI did not influence on results obtained for leaf, fruit and root, whereas GR activity was negatively influenced by the use of PRSI. The system PRSI, in the right way shown as a viable alternative for the reduction of negative effects provoked by the salty stress in the hybrid tomato Supera F1.
Tomato is one of vegetables most cultivated in greenhouses, standing out among the plants adapted to this cropping system. The production and fruit quality are directly related to the quality of water used for irrigation and its appropriate management. In order to propose management strategies for use of saline water irrigation in tomato crop production, the present study aimed to evaluate the growth and development of plants, yield and quality, and antioxidant responses of tomato cultivated under a partial salt stress of the root system. The experiment was carried out in a greenhouse at the Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró, RN, Brazil. The experimental design was completely randomized, with six treatments and four replicates, totaling 24 experimental units. The treatments consisted of six different irrigation managements using low and high saline water (S1-0.5 and S2-5.0 dS m-1), applied with or without the partial root-zone saline irrigation (PRSI). For the treatments T1, T2 and T3, the PRSI was not applied, whilst T4*, T5* and T6* treatments were under the PRSI. The number of leaves, leaf area, plant height, stem diameter and dry weight of leaf, stem, root and, fruit were determined as plant growth parameters. Cross diameter, lengthwise diameter, number of fruits per plant, mass average fresh fruit, yield, pH, pulp firmness, soluble solids content, titratable acidity, vitamin C, color relation (a*/b*), lycopene and β-carotene were determined as parameters for the fruit yield and quality evaluation, while antioxidante enzymes were used for oxidative stress evaluation. According to results, it was not observed deleterious effect of salinity on plant growth and assimilates, since that responses observed in all treatments were similar to T1 treatment (control). The best results of yield and quality responses were observed in T4* and T5* treatments. About antioxidants responses, the PRSI did not influence on results obtained for leaf, fruit and root, whereas GR activity was negatively influenced by the use of PRSI. The system PRSI, in the right way shown as a viable alternative for the reduction of negative effects provoked by the salty stress in the hybrid tomato Supera F1.
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Palavras-chave
Estresse oxidativo, Manejo de água, Salinidade, Solanum lycopersicum L., Oxidative stress, Salinity, Water management