Sepideh Dalvand; Hasan Mumivand; Bahman Zahedi; Abdollah Ehtesham Nia
Abstract
IntroductionBiostimulants, such as amino acids and nitrogen-containing compounds, play a vital role in the biochemical and physiological processes of plants. These molecules serve as ...
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IntroductionBiostimulants, such as amino acids and nitrogen-containing compounds, play a vital role in the biochemical and physiological processes of plants. These molecules serve as precursors and raw materials for the production of other essential compounds and are crucial for the regulation and control of cellular activities and various biological systems. Amino acids and nitrogen-containing compounds are essential for optimal plant growth and development, and improving nitrogen nutrition and amino acid management can enhance plant growth, yield, and resilience to environmental stresses. Foliar application of amino acids and nitrogen-containing biostimulants helps plants channel more of their stored energy into growth, development, and overall quality.Materials and MethodsThis study aimed to investigate the effects of amino acid and nitrogen-containing biostimulants on the growth, performance, and morpho-physiological and biochemical characteristics of fenugreek at Lorestan University. The experiment was conducted using a completely randomized design with 10 treatments and three replications. The treatments included a control (spraying with distilled water) and foliar applications of aspartic acid, glutamic acid, and nicotinic acid, each at three levels (75, 150, and 300 mg/L). The first foliar application was performed during the 4 to 6 leaf stage, with subsequent applications every 14 days (for a total of 4 applications).Results and DiscussionThe results indicated that applying nicotinic acid and aspartic acid at a concentration of 300 mg/L significantly increased plant height. Foliar application of all three biostimulants at concentrations of 150 and 300 mg/L resulted in a significant increase in leaf area and fresh weight of root. The application of nicotinic acid and aspartic acid also led to a significant increase in the fresh weight of the plant. However, the positive effect of nicotinic acid on plant fresh weight was greater than that of aspartic acid. Nicotinic acid treatment at all three levels increased the dry weight of plant. Foliar application of glutamic acid and aspartic acid at concentrations of 150 and 300 mg/L also increased the dry weight of plant. However, root dry weight increased only with concentrations of 150 and 300 mg/L of nicotinic acid and aspartic acid, and 300 mg/L of glutamic acid. Foliar application of all three compounds—glutamic acid, nicotinic acid, and aspartic acid—resulted in significant increases in chlorophyll a, chlorophyll b, and total chlorophyll. The most positive effect on chlorophyll was observed with aspartic acid application. Carotenoid levels were also significantly increased with the application of nicotinic acid and aspartic acid compared to the control, while glutamic acid only increased carotenoids at the highest concentration. Photosynthesis rate, stomatal conductance, CO2 concentration under the stomatal chamber, and total nitrogen were significantly increased with the foliar application of all three compounds—glutamic acid, nicotinic acid, and aspartic acid.ConclusionThe results of the present study showed that the application of biostimulants such as nicotinic acid, aspartic acid, and glutamic acid generally led to improvements in the studied characteristics. Overall, it can be concluded that the use of biostimulants, particularly nicotinic acid and aspartic acid (especially at a concentration of 300 mg/L), is recommended for improving the growth, performance, and morpho-physiological traits of fenugreek.
