Response of sorghum cultivars (Sorghum bicolor L.) to spraying different concentrations of salicylic acid

A field experiment was carried out at the second agricultural research station – College of Agriculture – University of Al-Muthanna during spring season 2022, to find out response of cultivars of sorghum (Rabih, Khair, Inqath) to spraying concentrations of salicylic acid. The experiment included 12 treatments represent between three cultivars (Rabih, Khair, Anqadh) and spraying of four concentrations of salicylic acid (0, 60, 90, 120)ppm, The Experiment was designed in split plots according to R.C.B.D with three replicates, The main plots included three cultivars of sorghum, while the secondary sub plots It included four levels of salicylic acid. Results showed that cultivar of Khair was superior at the traits Stem diameter, leaf area, no. of grains per ear which gave (20.35 mm, 303.00 cm2 and 1214 grain per- ear-1) respectively. As for salicylic acid the concentration 120 mg. L-1 was significant on the (no. grains per- ear, weight of 1000 grain and harvest index which gave (1461 grain per- ear -1, 33.30 g and 29.79 %) respectively. while the cultivar Khair excelled in the trait of leaf area and stem diameter (303.9 cm2 and 20.35 mm) respectively, as well as a significant effect of the level 120 ppm in the trait (number of days from planting to 75% flowering, number of leaves per plant, number of grains in ear, and Weigh of 1000 grains, grain yield, biological yield, harvest index (it amounted to 93.78) days, 9.45 leaf-1 , 1494 grain ear-1 , 32.96 g, 3.46 tons ha-1 , 12.59 tons ha-1 , 29.76%) sequentially. Significant effect of the interaction between the factors on the number of grains in the ear, as the combination (cultivars Inqath × level 120 ppm) recorded the highest average amounted to 2017 grain ear-1 .