Stress index, water potentials and leaf succulence in cauliflower cultivated hydroponically with brackish water

Adiel F Da S Cruz,Raquele M De Lira,Gerônimo F Da Silva,Ênio F De F E Silva,Jenyffer Da S G Santos,Hammady R E Soares

doi:10.1590/1807-1929/agriambi.v22n9p622-627

Adiel F Da S Cruz, Raquele M De Lira + Show 4 more

Open Access

https://doi.org/10.1590/1807-1929/agriambi.v22n9p622-627

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Abstract

ABSTRACT The tolerance of crops to salinity is greater in hydroponic systems due to the low contribution of the matric potential to the total potential of the water. The objective of this study was to evaluate the use of brackish water, to prepare the nutrient solution and replace the evapotranspired volume, and rates of application of this solution on the water stress index, water potential, leaf succulence and water consumption of cauliflower cv. ‘Piracicaba Precoce’. The experimental design was completely randomized in a 6 x 2 factorial scheme, with six salinity levels used to prepare the nutrient solutions (0.2, 1.5, 2.5, 3.5, 4.5 and 5.5 dS m-1) and two application rates of these solutions (1.5 and 2.5 L min-1), with four replicates. Water stress index (WSI), water and osmotic leaf potentials, leaf succulence (LS) and water consumption were analyzed. The increase in water salinity reduced LS and increased WSI. Water salinity reduced the water and osmotic leaf potentials and water consumption of the crop; however, the effects were more pronounced at the rate of 2.5 L min-1. Application rate of 2.5 L min-1 led to the highest WSI and lowest LS.

Highlights

Water scarcity in the world is a problem especially in countries with large semiarid regions, such as Brazil (Paulus et al, 2012)
Based on the hypothesis that nutrient solution salinity and application rates interfere with water and physiological relations of a crop, this study aimed to evaluate the use of brackish waters to prepare the nutrient solution and replace the evapotranspired volume, besides rates of application of this solution, on the water stress index, water potentials, leaf succulence and total water consumption of cauliflower
Regardless of the nutrient solution application rate, electrical conductivity of the solution (ECsol) tended to increase along the cycle from the treatment T2 (1.5 dS m-1) and such trend was more pronounced in the treatments T3 (2.5 dS m-1), T4 (3.5 dS m-1), T5 (4.5 dS m-1) and T6 (5.5 dS m-1)

Summary

Introduction

Water scarcity in the world is a problem especially in countries with large semiarid regions, such as Brazil (Paulus et al, 2012). Given the scenario of low supply of potable water, studies and generation of technologies that allow brackish waters to be used in food production are relevant (Paulus et al, 2010, 2012). Hydroponics emerges as an alternative technology that allows brackish waters to be used in the production of various crops, including vegetables (Santos et al, 2010; Soares et al, 2016). The increasing occurrence of problems related to water and soil salinity in this region has led to the need for identifying alternative forms of water management for the production of this crop. In Brazil and especially in its Northeast region, studies related to the cauliflower crop under hydroponic and saline conditions which could contribute to the technicalscientific community are still incipient

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