Grain yield and physiological growth indices in maize (Zea mays L.) hybrids under seed biopriming with plant growth promoting rhizobacteria (PGPR)

In order to study of grain yield and some of physiological growth indices in maize (Zen mays L.) hybrids under seed biopriming with plant growth promoting rhizobacteria (PGPR), a factorial experiment based on randomized complete block design with three replications was conducted in 2009 at the Research Farm of Mohaghegh Ardabili. Treatments were maize hybrids in three levels (SC-404. SC-410 and SC-434) plus seed biopriming with plant growth promoting rhizobacteria (PGPR) in four levels: without priming (as control), seed biopriming with Azotobacter chroococcum strain 5. Azospirillum lipoferum strain OF and Azotobacter chroococcum strain 5+Azospirillum lipoferum strain OF. Investigation of process of variances of dry matter accumulation indicated that in all of treatments, it increased slowly until 36 days after sowing and then increased rapidly till 116 days after sowing and from 116 clays after sowing till harvest time, it decreased clue to decreasing of crop growth rate and leaf area index. In addition, in all of maize hybrids, the highest dry, matter accumulation in unit of area was obtained at seed biopriming with Azotobacter. Seed biopriming also significantly increased the crop growth rate, and the maximum of it was observed by the plots with SC-434 seed priming with Azotobacter. In addition, in all of treatment compounds. CGR increased slowly until 67-68 clays after sowing and then decreased slowly till 76 days after sowing. From 76 days after sowing till harvest time, it decreased rapidly clue to increasing aging of leaves and decreasing of leaf area index. Mean comparisons showed that maximum grain yield (7.01 ton/ha) was obtained in SC-434 maize hybrid at seed biopriming with Azotobacter and minimum was in SC-404 without seed priming. Thus, it can be suggested that in order to increasing of grain yield and physiological growth indices, seed biopriming in SC-434 hybrid should be with Azotobacter chroococcum strain 5 in conditions of Ardabil Plain.