نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction
Wheat (Triticum aestivum L.) is one of the most important and oldest crops worldwide, playing a fundamental role in ensuring global food security. This plant is cultivated on a large scale due to its high adaptability to diverse environmental conditions and ease of cultivation. However, excessive and unbalanced use of chemical fertilizers has led to serious environmental problems including soil degradation, water pollution, biodiversity loss, and reduced product quality. Therefore, there is an increasing global trend toward using organic compounds and biological growth stimulants as effective strategies for sustainable agriculture. Among these, amino acids and humic acid have gained special attention due to their multiple beneficial effects on plant growth and soil fertility improvement. Despite numerous studies on the individual effects of these compounds on wheat, the appropriate timing of foliar application during critical growth stages, especially under the hot and dry climate of Khuzestan, has been less investigated. This study was therefore conducted to evaluate the effects of amino acid and humic acid foliar application at different growth stages on the quantitative and qualitative yield of wheat under the climatic conditions of Ahvaz.
Materials and Methods
The experiment was conducted during the 2025-2026 cropping year at the research farm of Islamic Azad University, Ahvaz Branch, located at 48°40' E longitude and 31°20' N latitude with an altitude of 22.5 m above sea level. The experiment was arranged as a factorial based on a randomized complete block design with three replications. Experimental factors included amino acid foliar application at three levels: no amino acid application (control), beginning of tillering + beginning of stem elongation, and beginning of tillering + beginning of stem elongation + beginning of booting stage; and humic acid foliar application at three levels: no humic acid application, beginning of tillering + beginning of stem elongation, and beginning of tillering + beginning of stem elongation + beginning of booting stage. The amounts of amino acid and humic acid applied were 3 and 5 L/ha, respectively, at each foliar application stage. Measured traits included spike number per square meter, spikelet number per spike, grain number per spike, grain number per spikelet, 1000-grain weight, grain yield, biological yield, harvest index, and grain protein percentage. Data were analyzed using SAS 12 software, and means were compared using Duncan's multiple range test at the 5% probability level.
Results and Discussion
Results showed that the main effects of amino acid and humic acid foliar application were significant on all studied traits at the 1% probability level. Furthermore, the interaction of amino acid and humic acid was significant on spike number per square meter, grain number per spike, grain yield, and biological yield at the 1% probability level. The highest spike number per square meter (430.24), grain number per spike (41.5), grain yield (485.1 g/m²), and biological yield (1405.2 g/m²) were obtained from the combined application of amino acid and humic acid at the three growth stages, showing increases of 26%, 33%, 43%, and 21%, respectively, compared to the control. The highest grain protein percentage (12.66%) and harvest index (33.34%) were obtained from the three-stage amino acid treatment. The synergistic effect of these compounds is attributed to improved soil structure and nutrient availability by humic acid, enhanced metabolic processes by amino acids, and better assimilate translocation to grains.
Conclusions
In conclusion, foliar application of amino acids and humic acid at different growth stages significantly improved the quantitative and qualitative yield of wheat under the hot and dry climatic conditions of Ahvaz. The combined application at the three stages of beginning of tillering, beginning of stem elongation, and beginning of booting stage, due to their synergistic effects, can be recommended as an effective and sustainable management strategy for increasing wheat yield in Ahvaz and similar regions. This approach reduces dependence on chemical fertilizers and contributes to sustainable agricultural production and environmental protection.
کلیدواژهها English
