Nitrogen (N) and Potassium (K) Supplementation to Improve Salt Tolerance in Brassica (Brassica juncea, cv: Agati sarheen)

M U Shirazi,M A Khan,R U Ansari,M T Rajput

doi:10.13189/ujps.2018.060101

Abstract

To observe the mitigating effects of nitrogen and potassium under salinity on Brassica juncea (cv. Agati sarheen), N and K was supplemented at different stages of growth. The studies were conducted under control condition (gravel culture). Salinity (12 dS/m) was imposed by NaCl salt after three weeks of germination through irrigation (1/4th Hoagland solution). Nitrogen and Potassium was applied exogenously in the form of KNO3 @ (T1. 30mM and T2 60mM) at vegetative and flowering stage. There was decrease in growth and yield under salinity. However; the relative reduction in plant height, slique length, grain wt/ 5 slique and grain yield/ 15 plants was comparatively low due foliar application of N and K as compared to non applicated plants. The overall accumulation of organic solutes (proline and glycine betaine) was significantly high under salinity. The response of N and K application was almost nil in case of proline accumulation. On the other hand application of KNO3 @ 30mM showed increased accumulation of glycine betaine. The uptake of Na under salinity was less in plant having KNO3 application @ 30mM (T1). Potassium content under saline condition was high in KNO3 @ 60mM (i.e. T2 treatment), resulting in high K/Na ratio. The application of KNO3 also found to increase in nitrogen content in brassica. It is therefore concluded that better performance of brassica genotype under salinity might be due to low Na uptake and high K/ Na ratio especially under T1 treatment (i.e KNO3 @ 30mM).

Highlights

Salinity is a major constrain in arid and semiarid areas of the world
The ability of plant to grow and complete its life cycle on saline soils is regarded as salt tolerance, which vary among the plant type and within genotypes of same species
The salt tolerance among the brassica species varies due to their physiological response e.g. electrolyte leakage, proline accumulation and the K/Na ratio

Summary

Introduction

Salinity is a major constrain in arid and semiarid areas of the world. About 6.8 million hectares, salt affected soils occupy in Pakistan (Khan,[1], Khan et al, [2], Shirazi, et al [3]), which is about 30% of the total cultivated area of Pakistan (Govt of Pakistans, [4]). It is reported that though the brassica species have high threshold values but the yield decrease is very high above the threshold values than most other crops in the tolerant category (Maas, [11] Ashraf and McNilly [12]). It is necessary to adopt suitable strategies for the improvement of growth and yield performance of brassica species under saline conditions. Nitrogen (N) and Potassium (K) Supplementation to Improve Salt Tolerance in Brassica (Brassica juncea, cv: Agati sarheen) and sunflower (Helianthus annuus L.) They reported that the improvement of these parameters is irrespective of the plant grown under non saline or saline conditions. The present study is designed to improve the yield performance of Brassica juncea (cv: Agati sarheen) grown under saline environment by the application of suitable doses of KNO3

Material and Methods

Results

Discussions