نوع مقاله : پژوهشی
نویسندگان
1 دانشجو کارشناسی ارشد اگروتکنولوژی-اکولوژی گیاهان زراعی، گروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه یاسوج، یاسوج
2 استادیار، گروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه یاسوج، یاسوج، ایران
3 دانشیار، گروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه یاسوج، یاسوج، ایران.
4 دانشآموخته کارشناسی ارشد اگروتکنولوژی-فیزیولوژی گیاهان زراعی، گروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه یاسوج، یاسوج،
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction:Red bean (Phaseolus vulgaris L.) is one of the key legumes in global nutrition due to its high content of proteins, fibers, and essential micronutrients. Although it is cultivated across various climates, this crop is highly sensitive to water deficit, and drought stress leads to yield reduction by disrupting key physiological processes. In this regard, the use of sustainable inputs, such as humic acid, has gained importance. Humic acid improves soil structure, enhances moisture retention, and facilitates nutrient uptake, thereby increasing plant resistance to drought. Therefore, its application can be considered an effective and eco-friendly approach to ensuring the sustainability of common bean production under climate change conditions. This study aimed to evaluate the effect of foliar application of humic acid on the physiological and biochemical traits of the red bean cultivar ‘Yaghout’ under water deficit conditions.
Materials and Methods: The experiment was conducted in 2023 in Boyer-Ahmad County as a split-plot arrangement within a randomized complete block design (RCBD) with three replications. The trial was arranged as a split-plot experiment based on a randomized complete block design with three replications. Irrigation treatments were assigned to the main plots at three levels, including full irrigation (100% of crop water requirement), moderate deficit irrigation (80% of crop water requirement), and severe deficit irrigation (60% of crop water requirement), determined using Class A pan evaporation. The subplots included foliar application of humic acid at four levels (0, 2.5, 5, and 7.5 L ha⁻¹). Data were statistically analyzed using SAS software, and mean comparisons were performed using the LSD test at the 5% significance level.
Results and Discussion: Severe drought stress significantly reduced leaf relative water content by 15.87%, indicating disturbance in water balance and the plant's ability to maintain turgor pressure. Simultaneously, electrolyte leakage increased by 47.65%, reflecting significant cellular membrane damage under drought conditions. Moreover, shoot phosphorus concentration decreased by 11.11%, likely due to reduced mobility and uptake of phosphorus in dry soil. In contrast, shoot potassium concentration increased by 45.55%, indicating its protective role in drought tolerance. Foliar application of 7.5 L ha⁻¹ humic acid enhanced peroxidase activity and carotenoid content by 68.04% and 55.22%, respectively, demonstrating activation of the antioxidant defense system and improved photosynthetic capacity. The interaction effects showed that under 60% irrigation, the highest humic acid level increased total chlorophyll content by 110% and grain yield by 20.66%. These findings suggest that humic acid ameliorates drought stress through enhanced nutrient availability, membrane stability, and improvement of vital physiological functions under water deficit conditions.
Conclusion: Overall, foliar application of 7.5 L ha⁻¹ humic acid can mitigate the adverse effects of water deficit on physiological traits and grain yield of common bean. Therefore, optimal foliar use of humic acid is recommended as an efficient and environmentally friendly strategy to enhance drought tolerance, maintain physiological integrity, and sustain yield of common bean under limited water conditions.
کلیدواژهها [English]
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