Abstract
Aiming to study the effect of arginine and pyruvic acid application on the amelioration of salt stress of barley plants, a pot experiments was conducted in the greenhouse of the National Research Centre in Dokkiu, Cairo Egypt. Salt concentration increases in water of irrigation induce adverse effect on barley plant height, and stem, leaves, spike and total dry weight. Arginine and pyrovic acid increased growth parameters but arginine effect on plant height and dry weight of leaves exceeded those from pyruvic acid>. The opposite was true for leaves area/main stem and stem, spikes and whole dry weight. Arginine and pyrovic acid increased growth parameters but arginine effect on plant height and dry weight of leaves exceeded those from pyruvic acid. The opposite was true for leaves area/main stem and stem, spikes and whole dry weight. Chl. and carotenoids increased and the opposite was true for chlorophyll b while chl.a+chl.b slightly affected when barley plants subjected to salt stress. Salt stress lowered chl.a:chl.b ratio and vice versa for ch.la+chl.b: carotenoids ratio. Arginine gave the highest values of Chl.a and Chl.a:Chl.b and under irrigation with fresh water but pyruvic acid gave it under saline condition. The vice versa was true for Chl.b and Chl.a+chl.b:carotenoids. However, the treating with pyruvic acid showed the highest effect under both irrigation treatments. The infestions with aphid decreased afier arginine and pyruvic acid under stress conditions.