Effect of foliar application of salicylic acid and biofertilizerson on yield and some biochemical traits of basil (Ocimum basilicum L.) under water stress

In order to study of the effect of foliar application of salicylic acid and biofertilizerson on yield and some biochemical traits of basil (Ocimum basilicum L.) under water stress, was investigated using a factorial experiment based on a randomized complete block design in triplicate within the 2019 crop year in the protected area of Horand city of the province of East Azarbaijan. Experimental treatments included the first factor of drought stress at three levels (70, 140 and 210 mm of evaporation from Class A evaporation pan), the second factor of seed inoculation with bacteria at five levels (no inoculation as control, inoculation with Azotobacter, Pseudomonas, Azospirillum and co-inoculation with Azotobacter, Pseudomonas and Azospirillum), and the third factor of salicylic acid foliar application at four levels (0, 0.5, 1 and 1.5 mM). With the application of dehydration, cell membrane stability, maximal photochemical efficiency of photosystem II and grain yield in basil decreased and carbohydrate accumulation, antioxidant enzyme activity, malondialdehyde content and essential oil content increased. The results of comparing the mean interaction of drought stress and biofertilizers showed that the highest grain yield (917.11 kg / ha) and maximum photochemical efficiency of photosystem II (0.713) were obtained from 70 mm evaporation treatment and the co-inoculation of bacteria (Azotobacter, Pseudomonas and Azospirillum). Salicylic acid (SA) foliar application increased 41.33%, 54.17%, 24.43% and 38.98% of glutathione peroxidase activity, leaf soluble carbohydrates, membrane stability index and essential oil content, and decreased the content of MDA by 54.72% respectively. According to the obtained results, foliar application with salicylic acid and the combined use of bacteria (Azotobacter, Pseudomonas and Azospirillum) could partially eliminate the negative effects of drought stress and improve the yield and quality of basil.