Effect of arbuscular mycorrhizal fungi and humic-fulvic acid on the agronomic characteristics of wheat (Triticum aestivum L.) in dryland conditions

To evaluate the effect of arbuscular mycorrhizal fungi (AMF) and humic-fulvic acid (HFA) on some quantitative and qualitative characteristics of rainfed wheat, this study conducted at the Agricultural Research and Education Center of West Azerbaijan, Iran during the growing season in 2017-18 and 2018-19. The experiment was conducted as a factorial randomized complete block design (RCBD) with three replications. The first factor consisted of three levels of bio-fertilizer application (1- non-application or control, 2- inoculation with Glomus intraradices (GI), 3- combination of fungal spices inoculation with G.mosseae, G.intraradices, and G.etunicatum (GM)). The second factor included two levels of HFA application including control (non-application) and seed treatment at 5% HFA/seeds. The results showed that root colonization was significantly affected by AMF treatments and increased from 9.89% in control to 30.57% and 40.71% in GI and GM, respectively. Wheat grain yield increased by 269 and 187 kg ha-1 in the GM and GI treatments, respectively (P≤0.05). Application of AMF treatments increased grain protein content, phosphorus (P), zinc (Zn), and copper (Cu) concentrations in the grain. GM treatment had higher efficiency than GI treatment in all the mentioned traits (P≤0.05). HFA seed treatment increased grain yield by 110 kg ha-1, root colonization (3.09%), and phosphorus concentration in the wheat grain (2.64 %)(P≤0.05). Therefore, wheat seed treatments with a compound inoculum of three species of AMF and HFA in dryland conditions increase the yield and protein content of the seed and enrich it with Zn and P nutrients under similar conditions to this experiment.