EMERGENCE, GROWTH AND PRODUCTION OF SESAME UNDER SALT STRESS AND PROPORTIONS OF NITRATE AND AMMONIUM

Adaan Sudario Dias,Reginaldo Gomes Nobre,Hans Raj Gheyi,Geovani Soares De Lima,João Batista Dos Santos

doi:10.1590/1983-21252017v30n221rc

Adaan Sudario Dias, Reginaldo Gomes Nobre + Show 3 more

Open Access

https://doi.org/10.1590/1983-21252017v30n221rc

Copy DOI

Abstract

ABSTRACT In arid and semi-arid regions, the quality of irrigation water varies in geographic terms and during the year, and the occurrence of water with high concentrations of salts is common. In this context, this study aimed to evaluate the emergence, growth and production of sesame, cultivar CNPA G3, irrigated with saline water and fertilized with N of different carrier proportions by the ratio of nitrate and ammonium ( NO --N and NH +-N) in an experiment conducted in lysimeters arranged in a greenhouse in the municipality of Campina Grande-PB, Brazil. The treatments were distributed into randomized blocks using a 5 × 5 factorial scheme relative to levels of irrigation water salinity (ECw; 0.6, 1.2, 1.8, 2.4 and 3.0 dS m-1) and five proportions of NO3 -N/NH4 -N (200/0; 150/50; 100/100; 50/150 and 0/200 mg of N kg-1), with three replicates. The increase in ECw compromised the emergence, growth and production of sesame, cultivar CNPA G3, and the production components were the most sensitive variables. The highest growth in diameter was obtained with the proportion of 200/0 mg kg -1 of NO3 -N/NH4 -N. An ECw level of 3.0 dS m and fertilization with 0/200 mg kg of NO3 -N/NH4 -N promoted deleterious effects on the total mass of sesame fruits and mass of seeds. The interaction between water salinity levels and NO3-/NH4 proportions significantly affected the number of leaves (at 50 and 70 days after sowing), the total mass of fruits and the mass of seeds.

Highlights

Sesame (Sesamum indicum L.) belongs to the Pedaliaceae family, and Africa is considered its center of origin due to the large number of species from the Sesamum genus on that continent (SOUSA et al, 2014)
The experimental design consisted of randomized blocks in a 5 × 5 factorial scheme, with three replicates, totaling 75 experimental units, in which the treatments resulted from the combination of five levels of irrigation water electrical conductivity (ECw; 0.6, 1.2, 1.8, 2.4 and 3.0 dS m-1), associated with five proportions of NO3--N and NH4+ -N (200:0, 150:50, 100:100, 50:150 and 0:200 mg N kg-1 of soil)
The salinity levels (SL) of the water used in the irrigation of the sesame cultivar CNPA G3 were prepared in order to obtain a proportion equivalent to 7:2:1 of Na+:Ca2+:Mg2+, respectively, using the salts NaCl, CaCl2·2H2O and MgCl2·6H2O, adjusting them to the electrical conductivity values of the public-supply water available in the municipality of Campina Grande-PB (ECw = 1.35 dS m-1)

Summary

Introduction

Sesame (Sesamum indicum L.) belongs to the Pedaliaceae family, and Africa is considered its center of origin due to the large number of species from the Sesamum genus on that continent (SOUSA et al, 2014). Sesame stands out in terms of good production stability relative to the water factor (low water requirement) compared to other cultivated species and constitutes an alternative source of income, especially for small and medium farmers in northeastern Brazil (ARAÚJO et al, 2014). In this region, the occurrence of high temperatures, low rainfall, irregular rainfall distribution and intense evaporation is common. Combined with the variability in the water quality used for irrigation, in both spatial and temporal terms, the occurrence of water with high concentration of salts is common (ALVES et al, 2011). The use of water with high concentrations of salts limits the growth and production of vegetables, due to the reduction in the osmotic potential of the soil solution, and may cause ionic toxicity, nutritional imbalances or both (FLOWERS, 2004)

Objectives

Methods

Results

Conclusion