Efeitos da salinidade sobre o desenvolvimento de rúcula cultivada em diferentes substratos hidropônicos.

Abstract

Resumo -Objetivou-se com este trabalho avaliar o efeito da salinidade na solução nutritiva sobre a produção de rúcula, cultivada em diferentes substratos. O ensaio foi desenvolvido em ambiente protegido do Departamento de Ciências Ambientais e Tecnológicas da Universidade Federal Rural do Semi-Árido em Mossoró-RN, e instalado em delineamento experimental inteiramente casualizado, em esquema fatorial 5 x 3, com três repetições. Foram utilizados cinco níveis de salinidade na solução nutritiva, obtidos com ou sem uso de água residuária da piscicultura (S 1 -0,5; S 2 -2,0; S 3 -3,5; S 4 -5,0 e S 5 -6,5 dS m -1 ) e três substratos (SUB1-Mistura de fibra de coco + areia + casca de arroz (1:1:1); SUB2-Cambissolo e SUB3-SUB1 reutilizado de experimento anterior). Realizou-se a colheita da rúcula aos 35 dias após a semeadura e avaliou-se as seguintes variáveis: altura de plantas, número de folhas, área foliar, massa fresca e massa seca. A salinidade da solução nutritiva afetou negativamente o desenvolvimento da rúcula, apresentando efeito variado de acordo com o tipo de substrato utilizado. As plantas cultivadas no substrato formado pela mistura de fibra de coco + areia + casca de arroz natural (1:1:1) apresentaram maior tolerância à salinidade. O substrato formado pela mistura de fibra de coco + areia + casca de arroz pode ser recomendado para o cultivo de rúcula em recipientes, mas não pode ser reutilizado sem tratamento.Palavras-chave -Eruca sativa. Estresse Salino. Hidroponia.Abstract -This study evaluated the effects of salinity on the nutrient solution on the production of rocket, grown on different substrates. The test was developed in an environment protected by the Department of Environmental Sciences and Technology, Federal Rural University of the Semi-Arid in Mossoró-RN, housed in a completely randomized design in a factorial 3 x 5 with three replications. Five salinity levels of nutrient solution were used, obtained with or without the fish farming wastewater (S1-0.5, S2-2.0, S3-3.5, S4-5.0 and S5-6.5 dS m -1 ) and three substrates (SUB1-Mix coconut fibre + sand + rice husk (1:1:1), SUB2-Cambisol and SUB3-SUB1 reused in the previous experiment). Harvesting of rocket was performed at 35 days after sowing and evaluated the following variables: plant height, leaf number, leaf area, fresh weight, and dry weight. The salinity of the nutrient solution negatively affected the development of the rocket grown, having effect varying according to the type of substrate used. The plants grown on the substrate formed by the mixture of coconut fibre + sand + rice hulls (1:1:1) showed higher tolerance to salinity. The substrate formed by mixing coir + sand + rice husk can be recommended for growing rocket containers, but cannot be reused without treatment.

Response of Arucula Cultivars to Saline Nutritive Solution Enriched With Potassium Nitrate

“…Negative effect of salinity on fresh matter of arucula was also reported in studies performed in substrates by other authors (Santos et al, 2012;Oliveira et al, 2013;Souza Neta et al, 2013), and in NFT system (Jesus et al, 2011;Silva et al, 2011Silva et al, , 2013.…”

“…Adverse effects of salinity in leaf area in arucula crop were reported by other authors (Souza Neta et al, 2013;Oliveira et al, 2013) and in other crops, such as lettuce (Dias et al, 2011), bell pepper (Nunes et al, 2013), and basil (Maia et al, 2017).…”

“…Many studies were already made to evaluate the effect of salinity on arucula crop on NFT hydroponic system (Silva et al, 2011;Santos et al, 2012) or grown in substrate (Oliveira et al, 2013;Souza Neta et al, 2013), and the results showed that the use of saline water on nutritive solution preparation promotes significant reduction on crop yield, even though it may occur great variation on crop response according to the adopted system and cultivar.…”

Initial development of watermelon in fuction of substrates and irrigation with saline water

“…In the evaluation of the substrates within the doses, it was verified that only in the lower electrical conductivity of irrigation water (0.3 dS m -1 ) the substrates promoted a change in the The increase of salinity beyond the minimum value estimated promoted an increment in the number of leaves, as verified by Souza Neta et al (2013) [20] in a study with arugula (Eruca sativa), who observed a variation in the number of leaves in response to the level of salinity and type of substrate used, corroborating with the data registered in the present study. According to the authors, the change in the concentration of salts in the substrate alters the physiological processes of plants, such as water absorption, meristematic activity, and consequent plant growth and development.…”

Ácido ascórbico e pigmentos fotossintéticos na alface crespa cultivada em sistema hidropônico com soluções salinas

“…A alface se destaca no cenário nacional de cultivos em hidroponia, sendo responsável por aproximadamente 80% da produção agrícola brasileira desse sistema (Alves et al, 2011). O uso da hidroponia surgiu como uma alternativa a problemas como a baixa disponibilidade de solos aptos à agricultura, o interesse em incrementar a eficiência do uso da água e o desejo de aumentar a produção e melhorar a qualidade dos alimentos (Souza Neta et al, 2013).…”