Efeito da concentração de nutrientes no crescimento, produtividade e qualidade de morangos em hidroponia

Abstract

<jats:p>Com o objetivo de estudar o efeito da concentração da solução nutritiva sobre o crescimento da planta, a produtividade e características químicas e fitoquímicas das frutas do morangueiro cultivar Camarosa em sistema hidropônico do tipo NFT, em Pelotas (RS), diferentes concentrações iônicas (CE) da solução foram avaliadas: 0,9; 1,5; 2,1; 2,7 dS m-1, em experimento realizado de 19/05 a 04/01/2010; e 0,7; 1,2; 1,7; 2,2 e 2,7 dS m-1, em experimento realizado de 07/06 a 04/01/2011. Avaliaram-se a matéria fresca e seca de folhas, coroa, raízes e frutas, a área foliar, o número de frutas e o peso médio das frutas. Amostras das frutas foram analisadas em relação ao teor de sólidos solúveis totais, à acidez titulável, às concentrações de antocianinas, ácido L-ascórbico, compostos fenólicos totais e à capacidade antioxidante, no segundo experimento. Os resultados indicaram que a CE entre 1,2 e 1,5 dS m-1 favorece o crescimento da planta e a produtividade. Quando a CE diminuiu de 1,7 para 1,2 dS m-1, os teores de sólidos solúveis, de antocianinas e de ácido L-ascórbico diminuíram em 17, 17 e 15%, respectivamente, e a produtividade e a concentração de compostos fenólicos totais aumentaram em 52 e 22%, respectivamente. O peso médio das frutas foi reduzido com a elevação da CE no primeiro experimento e não foi afetado, assim como a acidez titulável e a capacidade antioxidante, no segundo experimento. A solução nutritiva com CE entre 1,2 e 1,5 dS m-1 pode ser indicada para obter maior produtividade, sem grandes perdas na qualidade das frutas em sistema hidropônico NFT.</jats:p>

Foliar fertilization with gradual release of shale-based nutrients in strawberry and its effect on yield and compounds with functional potential

“…Camargo et al (2011), while evaluating chemical characteristics of eight strawberry cultivars, observed similar response to this study, and 'Camino Real' performed better than other cultivars regarding anthocyanin content. Portela et al (2012) found lower anthocyanin concentrations than those of this study for Camarosa cultivar grown in hydroponic culture (between 22.5 and 30.4 mg 100 g -1 depending on ionic concentration), which was similar to Bordignon Jr. 2008, who found 58.3 mg 100 g -1 content for Camarosa cultivar in soil cultivation.…”

“…Fruit phenolic compounds content and total antioxidant capacity are affected by plant genotype, culture conditions interaction, environmental conditions (temperature, UV, shade and light), management practices (Scalzo et al, 2005), ripeness degree, environmental conditions during harvest, post-harvest storage conditions and sample handling (Stern et al, 2010), increasing their levels in stress conditions. Portela et al (2012) found that phenolic compound levels ranging from 678.45 to 876.13 mg 100 g -1 for 'Camarosa' in soilless cultivation. Bordignon Junior (2008), found lower levels for this cultivar, 171.0 mg 100 g -1 in conventional system.…”

Productive and physiological responses of jambu (Acmella oleracea) under nutrient concentrations in nutrient solution

“…Thus, aiming quality production in sufficient amount, jambu cultivation under hydroponic system can be promising, since this system promotes greater input allocative efficiency, higher productivity and quality of products (Portela et al, 2012). Hydroponic system is a technique for growing plants without soil as a source of nutrients, so that these nutrients are available to the crop through a balanced nutrient solution (known as standard solution) which promotes growth and development of the cultivated plants.…”

“…Several formulations of standard nutrient solutions for leafy vegetables and fruits can be found in literature (Furlani, 1997;Furlani et al, 1999). However, it is worth mentioning that the formulations, as well as their ionic concentrations, can vary even within the plant species, since the absorption of nutrients varies with the cultivar, the developmental stage, the hydroponic system and the climatic conditions in which the crop is submitted (Portela et al, 2012).…”

Nutrient and inorganic solute (Na+ and Cl-) content in green onion plants under hydroponic cultivation using brackish water

“…According to Portela, Peil and Rombaldi (2012), the nutritional quality of foods is affected by the composition of the nutrient solution, by variations in the electrical conductivity (ECw) of this solution, and by the type of management adopted. However, hydroponics has emerged as an auxiliary technique to understand these effects on crops.…”