Standarisation of methodology for obtaining the desired salt stress environment for salinity effect observation in rice seedlings

The present investigation has been done to provide the salt stress treatments to rice seeds to observe the salinity effect on varieties under evaluation. The desired treatments of EC having salt concentration as 2, 4, 6, and 8 dS/m. The solutions were prepared on the basis of following established relationship between Total Dissolved Solid (TDS) and Electrical Conductivity (EC). Sodium chloride (NaCl) was used as solute and Distilled Water (D.W.) as solvent to prepare the solutions of desired EC. The calculated amounts of NaCl in g/l were dissolved in distilled water to get the respective EC for each solution. But using above calculation the EC obtained of each solution exceeds 12.5%-21% more than the desired EC. So, distilled water (D.W) was added to minimize the EC for desired value. It was observed that for EC 2 dS/m, 4 dS/m, 6 dS/m and 8 dS/m salt solution 1 gm, 2 gm, 3 gm and 4 gram of NaCl was required respectively. Thus a relationship has heen found that amount of sodium chloride required in terms of gram per litre is half of the desired EC in dS/m. It confirms the statement made in IRRI discussion paper series no. 22 (p7) by Gregorio et.al. 1997.