Effect of different methods of salicylic acid application in reducing the effects of salinity tension on wheat lands without drainage system

According to information extracted from Iran's soil resources and talent map, about 44.5 million hectares of Iran's area are salty lands. Salicylic acid is a plant growth regulator that increases plant tolerance to environmental tensions and improves plant metabolic activity. Therefore, the present experiment was conducted in order to investigate the effect of salinity tension on lands without drainage system and the role of salicylic acid in modifying its effects. This experiment was carried out as combination analysis in a randomized complete block design with three replication in the crop year of 2016-17 in agricultural lands of Shadegan city. Understudied treatments consisted of wheat under cultivation with two types of environments: 1- cultivation on normal lands (with drainage system) (first experiment) 2- cultivation in salty lands (without drainage system) (second experiment), and the second factor was the six method for the use of salicylic acid included non-use of salicylic acid (control), seed inoculation with salicylic acid, foliar application at the beginning of tillering, seed inoculation with salicylic acid in addition to foliar application at the beginning of tillering , foliar application at the end of tillering and seed inoculation with salicylic acid in addition to foliar application at the end of tillering . The results showed that the effect of cultivated land type on plant height, leaf area index, total dry matter, crop growth rate and net assimilation rate were significant at one percent probability level. The effect of salicylic acid on all measured traits was significant at one percent probability level. The interaction between environment and the method of salicylic acid application in terms of growth rate was significant at five percent probability level and was not significant for other traits. The maximum and the minimum amount of the investigated traits were observed in normal and salty lands, respectively, and among the various methods of using salicylic acid, the highest and lowest amount of traits was obtained in seedlings inoculation method with salicylic acid, in addition to foliar application at the beginning of tillering and without the use of salicylic acid (control).