Impact of foliar application using amino acids, yeast extract, and algae extract in different concentrations on growth parameters, yield traits, grain quality, and nitrogen-related parameters of wheat in arid environments

Wheat cultivation in arid environments faces significant challenges, necessitating innovative approaches to enhance productivity under current climate change conditions. Foliar application with bio-stimulants, such as amino acids, yeast extract, and algae extract, offers a sustainable solution to improve wheat growth, yield, and physiological efficiency under these conditions. A field trial was carried out over two winter growing seasons to assess the comparative effects of these bio-stimulants applied at varying concentrations on growth parameters, yield traits, grain quality, and nitrogen-related parameters. Treatments included an untreated control (sprayed with distilled water) and foliar applications at different concentrations: amino acids (1.5 and 3 ml/L), yeast extract (50 and 100 ml/L), and algae extract (5 and 10 ml/L). The results demonstrated that all bio-stimulant treatments significantly enhanced all studied parameters compared to the untreated control. The highest concentrations of each treatment (3 ml/L for amino acids, 10 ml/L for algae extract, and 100 ml/L for yeast extract) produced the greatest improvements, with amino acids at 3 ml/L exhibiting the strongest effects. Specifically, amino acids at 3 ml/L improved plant height by 12.46% and 21.56%, chlorophyll content by 22.32% and 19.12%, and plant dry weight by 63.30% and 70.38% in the first and the second seasons, respectively. Yield traits, including number of spikes, spike length, spike weight, number of spikelets per spike, number of grains per spike, and 1,000-grain weight, were also significantly improved, with amino acids at 3 ml/L producing the highest values. Grain yield, straw yield, and biological yield increased by 44.74% and 43.92%, 35.34% and 42.37%, and 36.29% and 43.95%, respectively, in the first and second seasons. Nitrogen content in both grains and straw was higher in treated plants, with amino acids at 3 ml/L enhancing grain nitrogen content by 25.52% and 22.50% and straw nitrogen content by 41.03% and 56.45% in the first and second seasons. The improvement resulted from amino acids at 3 ml/L followed by the application of algae extract at 10 ml/L and yeast extract at 100 ml/L, with all treatments showing significant improvements over the untreated control. Principal component analysis and heatmap analyses confirmed that higher concentrations of amino acids, algae extract, and yeast extract had the most positive effects on wheat growth and nitrogen-related parameters, while the untreated control and lower concentrations showed weaker results. These findings demonstrated that foliar application of amino acids, particularly at 3 ml/L, is a highly effective strategy for improving wheat productivity, grain quality, and nitrogen use efficiency in arid environments.