Salinity and cationic nature of irrigation water on castor bean cultivation

Geovani S De Lima,Lauriane A Dos A Soares,Carlos A V De Azevedo,Hans R Gheyi,Vera L A De Lima,Reginaldo G Nobre

doi:10.1590/1807-1929/agriambi.v22n4p267-272

Abstract

ABSTRACT This study aimed to evaluate the water relations, cell damage percentage and growth of the castor bean cv. ‘BRS Energia’ as a function of salinity and cationic nature of the water used in irrigation. The experiment was conducted in drainage lysimeters under greenhouse conditions in eutrophic Grey Argisol of sandy loam texture. Six combinations of water salinity and cations were studied (S1 - Control; S2 - Na+, S3 - Ca2+, S4 - Na+ + Ca2+; S5 - K+ and S6 - Na+ + Ca2+ + Mg2+), in a randomized block design with four replicates. In the control (S1), plants were irrigated with 0.6 dS m-1 water, whereas the other treatments received 4.5 dS m-1 water, obtained by adding different salts, all in the chloride form. Higher relative water content in the leaf blade of plants irrigated with K+-salinized water associated with leaf succulence are indicative of tolerance of the castor bean cv. ‘BRS Energia’ to salinity. Saline stress negatively affected castor bean growth, regardless of cationic nature of water. Among the ions studied, ‘BRS Energia’ castor bean was more sensitive to the presence of sodium in the irrigation water, in terms of both water relations and leaf succulence.

Highlights

Belonging to the Euphorbiaceae family, castor bean (Ricinus communis L.) is an oilseed crop that stands out in Northeast Brazil due to its characteristics of xerophilism and heliophilism, besides good adaptation to different soil and management conditions
This study aimed to evaluate the water relations, percentage of cell membrane damage and growth of the castor bean cultivar ‘BRS Energia’, as a function of salinity and cationic nature of the irrigation water
Among the other treatments (S1; S2; S4; S5 and S6), castor bean plants irrigated with S3 water deserve attention due to the lower %D, evidencing lower damages to the leaf tissue membrane

Summary

Introduction

Belonging to the Euphorbiaceae family, castor bean (Ricinus communis L.) is an oilseed crop that stands out in Northeast Brazil due to its characteristics of xerophilism and heliophilism, besides good adaptation to different soil and management conditions. It is a rustic crop, with fast growth, high yield and various possibilities of use for the oil extracted from its seeds (Marinho et al, 2010). Despite its importance for the semi-arid region of Northeast Brazil, the areas cultivated in this region are subject to agroclimatic variation, in which it is common the occurrence of high temperatures, low rainfall, irregular rainfall distribution and high evapotranspiration rates in most of the year, favoring the scarcity of surface waters. The irrigation practice is an important measure to guarantee water supply in moments of higher demands (Nobre et al, 2011)

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Results