Effects of glycine-betaine and mycorrhizal fungi application on the quantitative and qualitative performance of dryland wheat in field conditions

Reports are indicative of the promising effects of using mycorrhizal fungi and glycine betaine on enhancing drought tolerance in wheat (Triticum aestivium L.) and, thereby, increasing its yield and quality under rainfed farming. The present investigation was carried out as an on-farm experiment in Abadeh characterized by calcareous soils, Fars Province, in the 2021-22 growing season under field conditions. The experimental treatments included: 1) application of mycorrhizal fungi inoculum to seeds before cultivation + foliar spray of glycine betaine in accordance with the integrated plant nutrition system, and 2) the control involving common field management. The endomycorrhizal inoculum consisted of a mixture of the three species of Funneliformis mosseae, Rhizophagus irregularis, and Glomus etunicatum at 2% (2 kg with surfactant in 100 kg of seeds) and glycine betaine foliar spray applied at 5 mg L-1 during early stem node and booting stages. The measured characteristics consisted of grain yield components (No. of ears per m2, No. of grains per ear, and one thousand-grain weight), grain yield, biological yield, harvest index, and seed quality (grain concentrations of N, P, K, Fe, Mn, Zn, and Cu). The results showed that using mycorrhizal fungi and glycine betaine in the experimental treatment led to significantly rising yield as evidenced by the increased grain numbers per ear. Grain yield, biological yield, and harvest index in the experimental treatment were found to be higher by about 60%, 39%, and 14%, respectively, than those of the control. Furthermore, the wheat grain quality measures of nitrogen, phosphorus, iron, manganese, and zinc concentrations in the same treatment were found to have significantly increased. In general, it seems that application of seed-applied mycorrhizal fungi inoculant before planting along with glycine betaine foliar spraying is capable of increasing grain yield by 60% and improving crop quality (as indicated by grain nitrogen, phosphorus, iron, manganese, and zinc contents) under rainfed conditions, which leads to sustainable production and higher farmers` income.