BACKGROUND: Under water deficit conditions, use of growth-promoting bacteria and salicylic acid as a plant growth stimulant is very useful. OBJECTIVES: 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. METHODS: 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]. RESULT: 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. CONCLUSION: 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. تفاصيل المقالة

BACKGROUND: Salicylic acid exerts significant effects on plant morph physiology, playing a pivotal role in stimulating protective mechanisms and enhancing resistance against both biotic and abiotic stresses.OBJECTIVES: Current research was done to assess effect of biofertilizers and salicylic acid under non-irrigation conditions at different growth stages at corn crop production.METHODS: The study was done as a split-plot experiment, using Randomized Complete Block Design (RCBD) with three replications. The main plots consisted of different irrigation conditions at various growth stages (including full irrigation (control), non-irrigation from the flowering stage to the end of the growth period and non-irrigation from the beginning of the grain filling stage to the end of the growth period) and various combinations of biological fertilizers and salicylic acid treatments were implemented in the sub-plots (including the control treatment, 1 mM salicylic acid, nitroxin + biophosphorus bacteria grain rub and nitroxin + biophosphorus bacteria grain rub along with salicylic acid spraying).RESULT: The results indicated significant effects of irrigation treatments, biological fertilizers and salicylic acid, as well as their interactions, on leaf area index, yield and yield components. Non-irrigation from the flowering stage resulted in a substantial 58.3% reduction in grain yield compared to the control. However, the combined application of biological fertilizers and salicylic acid, under both non-irrigation and full irrigation conditions, led to a noteworthy increase in yield and yield components. In the non-irrigation treatment starting from the flowering stage and grain filling stages, the application of nitroxin + biophosphorus + salicylic acid bacteria treatment resulted in a significant increase in grain yield by 22.7% and 19.3%, respectively, compared to the control treatment. Moreover, the highest grain yield (with an average of 6552 kg.ha-1) was achieved through the combined effect of full irrigation and nitroxin + biophosphorus + salicylic acid foliar application.CONCLUSION: The application of non-irrigation during the grain filling stage, along with the combined use of nitroxin + biophosphorus grain treatment and salicylic acid foliar application, not only provided optimal conditions for the corn plant but also effectively mitigated the adverse effects of drought stress, resulting in yields equivalent to those achieved under normal irrigation conditions. تفاصيل المقالة