Doses de nitrogênio no acúmulo de nitrato e na produção da alface em hidroponia

Pôrto, Mônica Lima Alves; Alves, Jailson do Carmo; Souza, Adaílson Pereira de; Araújo, Raunira da Costa; Arruda, Jandeilson Alves de; Júnior, U. A. Tompson

doi:10.1590/s0102-05362012000300030

Cited by 11 publications

(11 citation statements)

References 16 publications

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“…In the aquaponic system, the role of the substrate has greater importance compared with the hydroponic system, because unlike the latter, in which the soluble nutrients added to the water are adequate for utilization by plants (Pôrto et al, 2012), in aquaponics, the nutrients need to be converted into easily available forms, such as organic nitrogen, which through the action of microorganisms is converted into ammonia, which is later transformed into nitrate through the action of nitrifying bacteria (Tokuyama et al, 2004;Rakocy et al 2006). Thus, the substrate for aquaponics has an additional function, acting as an adequate base for fixation of microorganisms (Hoque et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Yield of lettuce grown in aquaponic system using different substrates

Jordan

Geisenhoff

Oliveira

et al. 2018

Rev. bras. eng. agríc. ambient.

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A B S T R A C TIn the aquaponic system, the characteristics of the materials used as substrate directly affect plant development, because besides acting as a support base, they must present a surface to fix microorganisms, responsible for the conversion of nutrients into forms more easily available to plants. Thus, the objective of this study was to evaluate the effect of four growing substrates on the yield of lettuce grown in aquaponic system. The experimental design was randomized blocks with four treatments, which corresponded to the substrates, and six replicates. Plants were grown using the nutrient film technique (NFT) system. The substrates used in the experiment were: coconut shell fiber with crushed stone #3, expanded vermiculite, zeolite and phenolic foam. The treatment with phenolic foam was considered as the least suitable for lettuce cultivation in aquaponic system, because it caused lower yield (20.8 t ha -1 ). The treatment using coconut shell fiber with crushed stone #3 was considered as the most adequate, since it led to higher yield (39.9 t ha -1 ) compared with the other substrates analyzed.Produtividade da alface cultivada em sistema aquapônico sob diferentes substratos R E S U M O No sistema de aquaponia as características dos materiais utilizados como substrato afetam diretamente no desenvolvimento das plantas, pois além de atuarem como base de sustentação, devem apresentar uma superfície para fixação de microrganismos, responsáveis pela conversão de nutrientes para formas mais facilmente disponíveis para plantas. Assim, o objetivo desta pesquisa foi avaliar o efeito de quatro substratos de cultivo sobre a produtividade da alface cultivada em sistema de aquaponia. O delineamento experimental utilizado foi em blocos ao acaso, com quatro tratamentos que corresponderam aos substratos e seis repetições. O cultivo das plantas foi realizado utilizando o sistema do tipo NFT (Nutrient Film Technique). Os substratos utilizados no experimento foram: fibra de casca de coco com brita número 3, vermiculita expandida, zeólita e espuma fenólica. O tratamento em que se utilizou espuma fenólica foi considerado o menos adequado para o cultivo da alface em sistema aquapônico, pois apresentou menor produtividade (20,8 t ha -1 ). O tratamento em que se utilizou fibra de casca de coco com brita número 3 foi considerado o mais adequado, uma vez que proporcionou maior produtividade (39,9 t ha -1 ) em relação aos demais substratos analisados.

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Section: Introductionmentioning

confidence: 99%

Yield of lettuce grown in aquaponic system using different substrates

Jordan

Geisenhoff

Oliveira

et al. 2018

Rev. bras. eng. agríc. ambient.

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“…Researches on lettuce are mostly conducted regarding product quality analysis up to the commercial harvest time, and not to the final stages of development (FAVARO-TRINDADE et al, 2007;PÔRTO et al, 2012;RICARDO et al, 2014;PINTO et al, 2014). Therefore, additional studies assessing the chemical composition of vegetables until the end of their cycle are needed, in order to establish the limit time for the harvest, and offer consumers more than products with good appearance and taste, but also with better nutritional quality.…”

Section: Introductionmentioning

confidence: 99%

Physicochemical Characteristics of Purple Lettuce Harvested at Different Ages

et al. 2016

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-Lettuce is one of the most produced and consumed leafy vegetables in Brazil. It is harvested when the plant reaches full vegetative growth and the leaves are still tender and there are no signs of bolting. The plant is unsuitable for commercialization after this period, thus, a food that is rich in vitamins, minerals and bioactive compounds such as carotenoid is lost. Therefore, the objective of this work was to assess the purple lettuce quality based on physical-chemical characteristics, in three different ages. The experiment was conducted in an urban community garden in Sete Lagoas MG, Brazil. A completely randomized experimental design was used with three replications. The treatments consisted of three development stages (20, 30 and 40 days after transplanting -DAT). The treatment with 40 DAT presented total carotenoids concentration and soluble solids content significantly higher, lower pH, and darker lettuce, with lower values of the parameter b* (increase in yellow color), and higher values of the parameter a* (increase in red color), compared to the first two treatments. The titratable acidity was statistically equal for the three evaluation periods. Considering the high concentration of carotenoids found at 40 DAT, the harvest can take place at this age.Keywords: Development stages. Lactuca sativa. Harvest time. CARACTERÍSTICAS FÍSICO-QUÍMICAS DE ALFACE ROXA COLHIDAS EM DIFERENTES IDADESRESUMO -A alface é uma das hortaliças folhosas mais produzidas e consumidas no Brasil. A colheita ocorre no período em que a planta atinge o crescimento vegetativo máximo, as folhas ainda estão tenras e sem indícios de pendoamento. Após este período, a planta é considerada inadequada para a comercialização, perdendo-se um alimento rico em vitaminas, sais minerais e composto bioativos, como os carotenóides. Desta forma, este trabalho teve o objetivo de avaliar a qualidade com base em mudanças físico-químicas em uma cultivar de alface roxa durante três idades diferentes. O trabalho foi desenvolvido em uma horta comunitária urbana no município de Sete Lagoas -MG. O delineamento experimental foi inteiramente ao acaso com três repetições sendo os tratamentos os três estádios de desenvolvimento (20, 30 e 40 dias após transplantio -DAT). Aos 40 DAT, a concentração de carotenóides totais e o teor de sólidos solúveis totais foram significativamente superiores, o pH foi menor; e a alface se tornou mais escura, apresentando menores valores do parâmetro b* (incremento da cor amarela) e maiores valores do parâmetro a* (incremento da coloração vermelha), diferindo significativamente das duas primeiras colheitas. A acidez titulável foi igual estatisticamente nas três épocas de avaliação. Considerando o alto conteúdo de carotenóides observado aos 40 DAT, pode-se considerar a colheita nesta idade.Palavras-chave: Estádios de desenvolvimento. Lactuca sativa. Ponto de colheita.

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“…(Pepke, Cruz, Silva, Figueiredo, & Bicudo, 2013;Pietro-Souza, Bonfim-Silva, Schlichting, & Silva, 2013;Gomes, Silva, Gusmão, & Souza, 2012;Porto et al, 2012). However, production may be compromised due to lack of information about nitrogen fertilizer.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen Fertilization in Two Varieties of Basil

Yassue¹,

Achre²,

Pastório³

et al. 2018

JAS

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The cultivation of basil is worth mentioning, because it is a very promising crop. The aim of this study was to evaluate the development of the Basil cultivation, cultivar Tuscan lettuce leaf and Alfavaca red basilican, submitted to different doses of nitrogen. The first factor was composed of six nitrogen doses and one control (0, 40, 80, 120, 160, 200, 240 kg ha -1 of nitrogen), and the Second was composed of two cultivars (Alfavaca red basilican and Tuscan lettuce leaf) with four replicates. The basil Alfavaca red basilican cultivar overcame the cultivar Tuscan lettuce leaf in the plant height and diameter of the stem. In the leaf and shoot dry matter variables, the doses that resulted in the greatest increase of dry matter were 128 and 125.62 kg ha -1 of nitrogen for the cultivar Tuscan of lettuce leaf. Both Alfavaca red basilican and Tuscan lettuce leaf were influenced by nitrogen fertilization and the dose of 120 kg ha -1 of nitrogen has the highest potential in the developmental parameters.

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Doses de nitrogênio no acúmulo de nitrato e na produção da alface em hidroponia

Cited by 11 publications

References 16 publications

Yield of lettuce grown in aquaponic system using different substrates

Yield of lettuce grown in aquaponic system using different substrates

Physicochemical Characteristics of Purple Lettuce Harvested at Different Ages

Nitrogen Fertilization in Two Varieties of Basil

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