Abstract :
Salicylic acid is an important phenolic compound which can reduce the effects of saline condition on the plant through regulating it growth processes. In order to study the effects of time and amount of the application of salicylic acid on qualitative and quantitative yield of wheat, a factorial combination was conducted in an experimental farm in a randomized complete block design with 3 replicates in Islamic Azad University, Sabzevar Branch, in 2011. The aforementioned factors were investigated with respect to the time of application which entailed three stages (Tillering, stem elongation, and flowering) and with respect to the amount of salicylic acid application which encompassed four levels (0, 50, 100, and 150 mg/l). The findings reveal that the time of salicylic acid application exerts a significant effect on the economic and biologic yields, the number of seeds per spike as well as sodium, potassium, and protein percentages. The highest economic yield and the number of seeds per spike were observed in the stem elongation period. The amount of salicylic acid application had a significant effect on qualitative and qualitative yields of wheat as well. Most of the parameters studied at the time of application of 150 mg/l of salicylic acid were at the highest. The application of salicylic acid led to higher resistance to salinity by changing the way sodium and chlorine ions are absorbed. All in all, the findings show that application of 150 mg/l of salicylic acid at tillering stage is the most appropriate time of application for ensuring the optimum economic yield.
