Effect of plant growth promoting rhizobacteria, foliar application of amino acids and silicic acid on yield and yield components of wheat under drought stress

Drought is an abiotic stress that restrict water for agriculture. This experiment was conducted with irrigation factor at two levels includes {a1: Control, a2: cut irrigation after flowering stage} and the second experimental treatments at five levels includes{b1: control, b2: seed inoculated with bacteria (Azospirillum, Azotobacter, Pseudomonas), b3: seed inoculated with bacteria (Azospirillum, Azotobacter, Pseudomonas) and sprayed silicic acids, b4: seed inoculated with bacteria (Azospirillum, Azotobacter, Pseudomonase) and sprayed amino acids, b5: seed inoculated with bacteria (Azospirillum, Azotobacter، Pseudomonas) and sprayed silicic acids with amino acids} in randomized complete blocks design with four replicates using analysis of split plot. Results showed that drought stress reduced the traits measured, but seed inoculated with plant growth promoting bacteria, sprayed silicic acid and amino acids in normal irrigation and drought stress conditions increased seed 1000 weight, spike length, number of spikelet per spike, number of seeds per spike, biological yield and seed yield. Also seed inoculated with plant growth promoting bacteria and combined silicic acid and amino acid application increased seed yield in normal irrigation and drought stress about %27/76 and %44/64, respectively.