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Abstract(s)
Para crescerem, as culturas necessitam de solo, água, luz solar e calor apropriados.
No entanto, as alterações climáticas têm vindo a afetar a duração do período de cultivo,
as datas de floração e, o período de colheita ocorre mais cedo.
Em certas regiões mediterrânicas, algumas culturas poderão passar a ser cultivadas
no inverno, devido ao calor extremo e ao stress hídrico nos meses de verão. Noutras
regiões, como o oeste da França e o sudeste da Europa, prevê-se uma redução do
rendimento das culturas devido aos verões quentes e secos e à impossibilidade de
transferir a produção para o inverno.
Por outro lado, nos últimos anos tem-se verificado um crescente uso
de bioestimulantes no sector agrícola em detrimento dos fertilizantes sintéticos e
pesticidas. O aumento da procura por parte dos produtores agrícolas por produtos cada
vez mais naturais, e que contribuam para um aumento da produtividade e qualidade das
culturas agrícolas, parece caracterizar o caminho da agricultura na atualidade.
É assim imperativo avaliar a adaptabilidade das culturas ao deficit hídrico, bem
como incentivar o uso de bioestimulantes.
Em particular, o feijão, está entre os alimentos mais versáteis e comumente
consumidos em todo o mundo, e muitas variedades são cultivadas. Devido à sua
composição nutricional, e sendo um alimento de preço económico, tem o potencial de
melhorar a qualidade da dieta e a saúde a longo prazo daqueles que o consomem
regularmente.
O presente trabalho tem como objetivo avaliar o efeito da aplicação de três
bioestimulantes de base natural (Nomoren, Twin Anti-stress e X-stress) sob irrigação
normal e stress hídrico no crescimento da vagem de feijão “Rainha Roxa”; a influência
na composição nutricional, química e propriedades bioativas foi avaliada.
Observou-se um efeito variável com a aplicação dos bioestimulantes e o stress
hídrico nos parâmetros do valor nutricional; a frutose e a sacarose foram os principais
açúcares detetados, principalmente no tratamento NW+ e CW-, respetivamente. O ácido
oxálico e os ácidos málico e cítrico foram os ácidos orgânicos mais abundantes nos
tratamentos CW- e XSW+, respetivamente, enquanto o γ-tocoferol e o conteúdo total de
tocoferóis foram elevados no tratamento TWW+. (+)-Catequina e (-)-epicatequina foram
os compostos fenólicos mais abundantes, especialmente no tratamento TWW-. Verificou-se que a capacidade antioxidante foi variável nos ensaios de TBARS e
OxHLIA, enquanto os extratos hidroalcoólicos referentes ao tratamento TWW+
apresentaram melhor potencial contra os fungos testados neste trabalho.
Os bioestimulantes testados apresentaram um efeito positivo na composição
química e bioatividades na vagem do feijão roxo dependendo do regime de irrigação.
In order to grow, crops need appropriate soil, water, sunlight and appropriate heat. However, climate change has been affecting the length of the growing season, flowering and harvest dates occur several days earlier. In certain Mediterranean regions, some crops may be grown in winter, due to extreme heat and water stress in the summer months. In other regions, like western France and southeastern Europe, a reduction in crop yield is expected due to hot and dry summers and the impossibility of transferring production to winter. On the other hand, in recent years there has been an increasing use of biostimulants in the agricultural sector to the detriment of synthetic fertilizers and pesticides. Agricultural producers are looking for increasingly natural products, and that contribute to an increase in productivity and quality of agricultural crops, seems to characterize the path of agriculture today. It is therefore important to assess the adaptability of crops to water deficit, as well as to encourage the use of biostimulants. Particularly, beans are among the most versatile and commonly eaten foods throughout the world, and many varieties are grown in the U.S. Because of their nutritional composition, these economical foods have the potential to improve the diet quality and long-term health of those who consume beans regularly. The present work studied the effects of three biostimulant products (Nomoren, Twin Anti-stress and X-stress) under normal irrigation and water stress conditions on the nutritional, chemical composition and bioactive properties of purple bean fresh pods. A variable effect of biostimulants and water stress was observed on nutritional value parameters, while fructose and sucrose were the main detected sugars, especially in NW+ and CW- treatments, respectively. Oxalic acid and malic and citric acids were the main detected organic acids in CW- and XSW+ treatments, respectively, while γ- and total tocopherols content was the highest in TWW+. (+)-Catechin and (-)-epicatechin were the most abundant phenolics, especially in the TWW- treatment. A variable antioxidant capacity was observed for the TBARS and OxHLIA assays, while TWW+ hydroethanolic extracts showed the best overall potency against the tested fungi. In conclusion, the tested biostimulants had a positive effect on chemical composition and bioactivities of purple bean depending on the irrigation regime.
In order to grow, crops need appropriate soil, water, sunlight and appropriate heat. However, climate change has been affecting the length of the growing season, flowering and harvest dates occur several days earlier. In certain Mediterranean regions, some crops may be grown in winter, due to extreme heat and water stress in the summer months. In other regions, like western France and southeastern Europe, a reduction in crop yield is expected due to hot and dry summers and the impossibility of transferring production to winter. On the other hand, in recent years there has been an increasing use of biostimulants in the agricultural sector to the detriment of synthetic fertilizers and pesticides. Agricultural producers are looking for increasingly natural products, and that contribute to an increase in productivity and quality of agricultural crops, seems to characterize the path of agriculture today. It is therefore important to assess the adaptability of crops to water deficit, as well as to encourage the use of biostimulants. Particularly, beans are among the most versatile and commonly eaten foods throughout the world, and many varieties are grown in the U.S. Because of their nutritional composition, these economical foods have the potential to improve the diet quality and long-term health of those who consume beans regularly. The present work studied the effects of three biostimulant products (Nomoren, Twin Anti-stress and X-stress) under normal irrigation and water stress conditions on the nutritional, chemical composition and bioactive properties of purple bean fresh pods. A variable effect of biostimulants and water stress was observed on nutritional value parameters, while fructose and sucrose were the main detected sugars, especially in NW+ and CW- treatments, respectively. Oxalic acid and malic and citric acids were the main detected organic acids in CW- and XSW+ treatments, respectively, while γ- and total tocopherols content was the highest in TWW+. (+)-Catechin and (-)-epicatechin were the most abundant phenolics, especially in the TWW- treatment. A variable antioxidant capacity was observed for the TBARS and OxHLIA assays, while TWW+ hydroethanolic extracts showed the best overall potency against the tested fungi. In conclusion, the tested biostimulants had a positive effect on chemical composition and bioactivities of purple bean depending on the irrigation regime.
Description
Keywords
Phaseolus vulgaris L. cv. Rainha Roxa Bioestimulantes Stress hídrico Composição química Bioatividades