Effect of tillage and salicylic acid on some of biochemical traits of two varieties of fodder vetch under rainfed condition

In order to investigate the biochemical respnces and performance of two vetch cultivars to tillage and salicylic acid in dry conditions, two vetch cultivars of Maragheh and Gachsaran were sprayed at four levels of salicylic acid 0, 0.5, 1 and 1.5 mM, were investigated as a split plot in the form of randomized complete block design with four replications in three environments including conventional tillage (ploughing with reversible plow and disc), low tillage (protection plowing with chisel packer) and no tillage. The results showed that the highest amount of proline in shoot was without significant difference from the low tillage method in Maragheh variety with the application of zero, 0.5 and 0.1 mM salicylic acid (5.8 mg/g fresh weight), and the lowest was obtained from conventional tillage method in Gachsaran cultivar with application of 0.5 and 0.1 mM salicylic acid (3.4 mg/g fresh weight). The highest amount of shoot peroxidase from the low tillage method in Maragheh and Gachsaran cultivars (without significant difference, 152 and 151 micrograms of protein per minute, respectively) and the lowest was obtained from the conventional tillage method in Maragheh cultivar without the use of salicylic acid (133 micrograms of protein per minute). The highest amount of raw seed protein from conventional tillage method in Maragheh variety with application of zero and 0.1 mM salicylic acid (29.2%) and the lowest amount was achieved from low tillage method in Gachsaran variety without application of salicylic acid (25.7%). The trend of changes in seed yield and shoot proline under the influence of salicylic acid showed that by increasing salicylic acid application up to 1.5 mM, these two traits increased by 10.5% and decreased by 12.3% compared to the control treatment. In total, the results showed that the reactions of biochemical traits to tillage, salicylic acid and variety were different, but the method of low tillage in Maragheh cultivar with foliar spraying of 1.5 mM salicylic acid by creating favorable conditions for growth caused a decrease in proline content and increased grain yield.