Evaluation Effect of Growth-stimulating Bacteria and Salicylic Acid on Growth Physiological Indices and Grain Yield of Corn (Zea mays L.) under Non-irrigation Conditions at Different Growth Stages

Under water deficit conditions, use of growth-promoting bacteria and salicylic acid as a plant growth stimulant is very useful.
This research was conducted to assess effects of biological fertilizers and salicylic acid under non-irrigation conditions at different growth stages on growth indices and crop production of corn during 2016 cropping season.
The study was done via split-plot experiment, based on Randomized Complete Block Design with three replications. The treatments included full irrigation (control), non-irrigation from flowering stage to the end of growth period, non-irrigation from the beginning of the grain filling stage to the end of the growth period, belonged to main plots and biological fertilizers and salicylic acid treatment were placed in sub-plots [control treatment, 1 mM salicylic acid, nitroxin + biophosphorus bacteria grain rub, nitroxin + biophosphorus bacteria grain rub along with salicylic acid spraying].
The results showed that the full irrigation treatment significantly improved the growth physiological indices such as the leaf area index. The combination of nitroxin, biophosphorus and salicylic acid had a positive and significant effect on the examined indicators. The effects of non-irrigation treatments, biological fertilizers, salicylic acid and their interaction effect on grain yield were significant. Non-irrigation from flowering stage reduced the grain yield by 58.3% compared to the control. The combined application of biological fertilizers + salicylic acid in treatments of non-irrigation and full irrigation significantly increased the grain yield. In the treatment of non-irrigation from flowering and early grain filling, the nitroxin + biophosphorus + salicylic acid bacteria treatment increased the grain yield by 22.7% and 19.3%, respectively, compared to the control. The maximum grain yield (6552 kg.ha-1) belonged to the full irrigation treatment and nitroxin + biophosphorus + salicylic acid foliar application.
In case of non-irrigation during grain filling stage, by use Nitroxin + biophosphorus bacteria grain rub treatment along with salicylic acid foliar application, also to provide suitable conditions for corn growth, a significant amount of drought stress effect can be reduced and obtained yield under normal conditions.