Physiological and vegetative behavior of banana cultivars under irrigation water salinity

Edvaldo B Santana Júnior,Jailson L Cruz,Eugênio F Coelho,Karoline S Gonçalves

doi:10.1590/1807-1929/agriambi.v24n2p82-88

Abstract

ABSTRACT The purpose of the study was to evaluate the effect of salinity levels of irrigation water on physiology and growth of banana cultivars during the vegetative stage. The experiment was carried out following a completely randomized design in split plots, with four levels of salinity in irrigation water (0.5, 2.0, 3.0 and 4.0 dS m-1) and four banana cultivars (Pacovan, Prata Anã, BRS Platina and Princesa) with three repetitions. Stomatal conductance, transpiration, relative water content, leaf water potential and proline concentration were evaluated at 150 days after transplanting (DAT), besides plant height, stem diameter and leaf area. All variables showed sensitivity to the increase of salinity level of irrigation water. The results of soil water extraction, relative water content in leaf (RWC), leaf water potential and proline content differed (p ≤ 0.05) among the cultivars. Prata Anã and BRS Platina cultivars were the ones with lowest sensitivity, while Pacovan and BRS Princesa cultivars showed larger variation of soil water extraction and RWC with the increase in irrigation water salinity (electrical conductivity), being considered the ones of highest sensitivity to salinity in this study. Banana crop growth as a consequence of physiological effects was inhibited by the increase in water salinity, mainly in “BRS Princesa” cultivar.

Highlights

Banana (Musa spp) is considered one of the most important crops commercially cultivated worldwide, with an estimated production of 113 million tons in an area of 5.6 million hectares (FAOSTAT, 2017)
Salinity is one of the abiotic stresses that most compromise agricultural production, especially in arid and semiarid regions, where the problems caused by salinization are even more accentuated due to the characteristics of the soil, climatic conditions and the inadequate irrigation management performed by some irrigators, which can favor the accumulation of salts in soil and water (Cova et al, 2016)
The reduction of stomatal conductance with the increase in electrical conductivity (EC) of the water applied to the soil was possibly due to the increased resistance to CO2 diffusion, caused by the high levels of irrigation water salinity in the soil solution (Silveira et al, 2010; Silva et al, 2011; Kusvuran, 2012)

Summary

Introduction

Banana (Musa spp) is considered one of the most important crops commercially cultivated worldwide, with an estimated production of 113 million tons in an area of 5.6 million hectares (FAOSTAT, 2017). The use of irrigation water with salt contents above the limit tolerated by the crop can cause significant reduction in its growth, which may lead to severe losses in the final production. Salt stress can induce physiological modifications and compromise crop growth, development and production (Freire et al, 2014). In susceptible species, it is manifested by severe reductions in growth, water and photosynthetic exchange activities, disorders in membrane permeability and ionic balance (Cavalcante et al, 2010), besides damaging the stomatal conductance and/or diffusive resistance, transpiration and leaf temperature (Nascimento et al, 2011; Taiz et al, 2017). The increase in the concentration of salts in the soil solution causes the water to become increasingly less available to plants and, once the soil has reduced osmotic potential in the solution, water extraction by plants is substantially affected (Alves et al, 2011; Iqbal et al, 2014)

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Conclusion