Water relations of chives in function of salinity and circulation frequency of nutrient solutions

Abstract

Hydroponic cultivation using saline waters is an alternative for agricultural production, especially in the cultivation of vegetables. Therefore, the present work was conducted with the objective of evaluating the water consumption, water use efficiency and water content, as well as dry matter partitioning of chives (Allium schoenoprasum), cv. Todo Ano Evergreen -Nebuka exposed to six levels of nutrient solution salinity (1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 dS m -1 ), applied at two circulation frequencies (twice a day at 8 and 16 h; and three times a day -at 8, 12 and 16 h). The level in the nutrient solution reservoir, which decreased according to the water consumption by plants, was replaced with the respective saline water (Experiment I) and supply water (Experiment II). Both experiments used a completely randomized design, in a 6 x 2 factorial scheme, with five replicates. It was observed that increased circulation frequency and the use of supply water in the replacement mitigated the effects of salinity on water consumption, water use efficiency and water content in the plant. However, with the increase in nutrient solution electrical conductivity, dry matter allocation in the roots increased, to the detriment of the shoots.Relações hídricas da cebolinha em função da salinidade e frequência de circulação de soluções nutritivas RESUMO: O cultivo hidropônico com o uso de águas salobras, constitui-se em uma alternativa para a produção agrícola, especialmente no cultivo de hortaliças. Sendo assim, desenvolveu-se o presente trabalho com o objetivo de avaliar o consumo, eficiência e o teor de água, bem como a partição de massa seca de plantas de cebolinha (Allium schoenoprasum), cultivar Todo Ano Evergreen -Nebuka, expostas a seis níveis de salinidade da solução nutritiva (1,5; 3,0; 4,5; 6,0; 7,5 e 9,0 dS m -1 ), aplicados em duas frequências de circulação (duas vezes ao dia -às 8 e 16 h; e três vezes ao dia -às 8, 12 e 16 h). O nível do reservatório de solução nutritiva, que reduzia em função do consumo hídrico das plantas, foi reposto com a respectiva água salobra (Experimento I) e de água de abastecimento (Experimento II). Nos dois ensaios, adotou-se delineamento experimental inteiramente casualizado, analisado em esquema fatorial 6 x 2, com cinco repetições. Verificou-se que o aumento da frequência de circulação e o uso de água de abastecimento na reposição, mitigaram os efeitos da salinidade sobre o consumo e eficiência do uso e o teor de água na planta. Entretanto, com o incremento da condutividade elétrica da solução nutritiva, a alocação de matéria seca na raiz aumentou, em detrimento da parte aérea.Palavras-chave: Allium schoenoprasum, cultivo de hortaliças, cultivo sem solo

Production, water-use efficiency and post-harvest quality of hydroponic mini watermelon under salinity stress1

“…Considering that a high salinity may cause disorders such as water deficit and nutritional imbalances (Silva Júnior et al 2019), the reduction of rind thickness induced by salinity can be explained, at least in part, by these disorders, as reported by Azevedo et al (2016). These authors evaluated the frequency of fertigation in 'Crimson Sweet' watermelon, in a conventional cultivation system, and observed that a higher frequency increased the rind thickness, stating that, for watermelon, this response is related to a greater availability of water and nutrients.…”

Photochemical efficiency of basil cultivars fertigated with salinized nutrient solutions

“…In the hydroponic system, the quality of the water used to prepare the nutrient solution, regarding the content of salts, is a factor of great importance, because the use of saline water (ECw > 3.5 dS m -1 ) can cause reductions in plant growth and yield, although there are differences between species regarding the tolerance to nutrient solution salinity (Martins et al, 2019;Rosas et al, 2019;Silva Júnior et al, 2019;Soares et al, 2019). Basil is classified as tolerant or moderately tolerant to salinity, showing slight reduction of growth under salinity of 5.0 dS m -1 (Attia et al, 2009); however, this level of tolerance depends on numerous factors, especially on the genotype (Maia et al, 2017;Menezes et al, 2017).…”