Impactos fisiológicos e bioquímicos causados pela deficiência hídrica em plantas de pimentão (Capsicum annuum L.)
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Data
2018-11-13
Autores
Machuca, Luz María Ruiz
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O pimentão é uma cultura de grande interesse agrícola e econômico para o Brasil. Como hortaliça, demanda práticas de irrigação, para garantir a produção e qualidade de frutos. Devido à dependência direta da água para seu manejo, este recurso pode ser fator limitante para o desenvolvimento da cultura. Neste contexto, este estudo teve como objetivo avaliar as diferenças na morfologia e fisiologia em plantas de pimentão, submetidas a diferentes lâminas de irrigação nas estações inverno e verão. As plantas foram cultivadas em vasos de 22 Kg de solo, utilizando o sistema de irrigação por gotejamento. O desenho experimental foi organizado em delineamento inteiramente casualizado (DIC) com três tratamentos e cinco repetições. Os tratamentos foram divididos em controle (C; Ψm do solo= 10 a 15 KPa); Deficiência Hídrica Moderada (DHM; Ψm do solo= 34- 40 KPa) e Deficiência Hídrica Severa (DHS; Ψm do solo= 54 a 60 KPa). As plantas se mantiveram sem restrição hídrica até os 50 dias após transplantio (DAT). Foram realizadas quatro avaliações aos 50, 65, 80 e 95 DAT em que as plantas foram coletadas e separadas para avaliar o potencial hídrico foliar (ψhf), conteúdo relativo de água, perda de eletrólitos, biometria, avaliação nutricional da folha, variáveis fisiológicas, discriminação isotópica do δ13C e δ15N e análises bioquímicas. Finalmente coletou-se frutos para determinação da produtividade. A deficiência hídrica (DH) provocou redução no potencial hídrico foliar, ocasionando diminuição geral dos parâmetros avaliados o que resultou em perdas consideráveis na produção de frutos. No entanto, o tratamento DHS ocasionou danos mais marcantes no crescimento e produtividade da cultura de pimentão. Os resultados obtidos confirmaram a hipótese da dependência da água no crescimento e produtividade da cultura do pimentão em ambiente protegido.
Bell pepper is a crop of great agricultural and economic interest to Brazil. As a vegetable, it demands irrigation practices, to guarantee the production and quality of fruits. Due to the direct dependence of water for its management, this resource can be a limiting factor for the development of the crop. In this context, this study had as objective to evaluate the differences in morphology and physiology in Bell pepper plants, submitted to different irrigation depths in winter and summer seasons. The plants were cultivated in pots of 22 kg of soil, using the drip irrigation system. The experimental design was arranged in a completely randomized design (CRD) with three treatments and five replicates. The treatments were divided in control (C; Ψm of soil = 10 to 15 KPa); Moderate Water Deficiency (MWD; Ψm of soil = 34-40 KPa) and Severe Water Deficiency (SWD; Ψm of soil = 54 to 60 KPa). The plants were maintained without water restriction until 50 days after transplanting (DAT). Four evaluations were performed at 50, 65, 80 and 95 DAT in which the plants were collected and separated to evaluate leaf water potential (ψlw), relative water content, electrolyte loss, biometry, leaf nutrient evaluation, physiological variables, isotopic discrimination of δ13C and δ15N and biochemical analyzes. Fruits were finally collected for yield determination. The water deficit (WD) caused a reduction in the leaf water potential, causing a general decrease of the evaluated parameters, which resulted in considerable losses in the fruit production. However, the SWD treatment caused more marked damages in the growth and productivity of the Bell pepper crop. The results confirmed the hypothesis of water dependence on the growth and productivity of the pepper crop in a protected environment.
Bell pepper is a crop of great agricultural and economic interest to Brazil. As a vegetable, it demands irrigation practices, to guarantee the production and quality of fruits. Due to the direct dependence of water for its management, this resource can be a limiting factor for the development of the crop. In this context, this study had as objective to evaluate the differences in morphology and physiology in Bell pepper plants, submitted to different irrigation depths in winter and summer seasons. The plants were cultivated in pots of 22 kg of soil, using the drip irrigation system. The experimental design was arranged in a completely randomized design (CRD) with three treatments and five replicates. The treatments were divided in control (C; Ψm of soil = 10 to 15 KPa); Moderate Water Deficiency (MWD; Ψm of soil = 34-40 KPa) and Severe Water Deficiency (SWD; Ψm of soil = 54 to 60 KPa). The plants were maintained without water restriction until 50 days after transplanting (DAT). Four evaluations were performed at 50, 65, 80 and 95 DAT in which the plants were collected and separated to evaluate leaf water potential (ψlw), relative water content, electrolyte loss, biometry, leaf nutrient evaluation, physiological variables, isotopic discrimination of δ13C and δ15N and biochemical analyzes. Fruits were finally collected for yield determination. The water deficit (WD) caused a reduction in the leaf water potential, causing a general decrease of the evaluated parameters, which resulted in considerable losses in the fruit production. However, the SWD treatment caused more marked damages in the growth and productivity of the Bell pepper crop. The results confirmed the hypothesis of water dependence on the growth and productivity of the pepper crop in a protected environment.
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Palavras-chave
Pimenteiro, níveis de irrigação, trocas gasosas, atividade enzimática, discriminação isotópica, produtividade, Pepper, irrigation depths, gas exchange, enzymatic activity, isotopic discrimination, productivity