تاثیر کلات آهن و اسید هیومیک بر صفات زراعی و فیزیولوژیکی ارقام گلرنگ (carthamus tinctorius l.) تحت شرایط دیم

به‌منظور ارزیابی نحوه تاثیر دو نوع کود (آهن و اسید هیومیک) بر روی صفات عملکردی و فنولوژیک دو رقم گلرنگ (carthamus tinctorius l.) این تحقیق در مرکز تحقیقات کشاورزی اردبیل انجام گرفت. این آزمایش به‌صورت کرت‌های خردشده در قالب طرح بلوک‌های کامل تصادفی در سه تکرار انجام گرفت. عامل اصلی ارقام گلرنگ (گلدشت و چینی (xys)) بودند. عامل فرعی یعنی کود دارای نُه سطح بود. سطوح کودی شامل سطح شاهد، دو میلی‌گرم در لیتر و چهار میلی‌گرم در لیتر اسید هیومیک 95 درصد، دو سطح کود کلات آهن 12 درصد  edta(یک میلی‌گرم در لیتر و دو میلی‌گرم در لیتر) و چهار سطح متقابل کود‌های آهن و اسید هیومیک بودند. نتایج حاصل از این پژوهش تفاوت معنی‌دار در صفات عملکردی را دو رقم چینی و گلدشت نشان داد. براساس مشاهدات، رقم گلدشت با عملکرد دانه 1462.5 کیلوگرم در هکتار نسبت به رقم چینی به‌طور معنی‌داری برتری داشت. همچنین تیمار کودی تیمار دو میلی‌گرم در لیتر آهن + چهار میلی‌گرم در لیتر هیومیک به‌طور معنی‌داری بیشترین عملکرد را ایجاد کرد که باعث افزایش 49 درصدی عملکرد دانه نسبت به شاهد شد. بین ارقام از نظر ارتفاع بوته و فعالیت آنتی‌اکسیدانی اختلاف معنی‌داری وجود نداشت، امّا در بین سطوح کودی، برای ارتفاع سطح دوم اسید هیومیک با 68.3 سانتی‌متر و برای فعالیت آنتی‌اکسیدانی تیمار دو میلی‌گرم در لیتر آهن + چهار میلی‌گرم در لیتر هیومیک با میزان 84.5 درصد فعالیت بیشترین میزان را داشتند. در مجموع در بین ارقام، رقم گلدشت و در بین سطوح کودی تیمار دو میلی‌گرم در لیتر آهن + تیمار چهار میلی‌گرم در لیتر هیومیک ، بیشترین عملکرد بیولوژیک، بیشترین شاخص برداشت، بیشترین عملکرد روغن دانه و بیشترین عملکرد دانه را داشتند.

the effect of chelated iron and humic acid on agronomic and physiological traits of safflower (carthamus tinctorius l.) cultivars under rainfed conditions

introductionsafflower, scientifically known as carthamus tinctorius l., is an annual plant belonging to the asteraceae family. today, with the development of high-yield varieties that produce substantial quantities of high-quality oil, safflower is recognized as one of the world’s important oilseed crops. given its strong resistance to salinity and ability to grow under rain-fed conditions, it is considered a drought-tolerant plant—an attribute that significantly enhances its value. additionally, humic acid, as an organic compound, poses minimal harm to the environment. additionally, through its hormone-like activity, it has many positive effects on various traits, including performance characteristics. the presence of micronutrients, especially fe, enhances the plant’s resistance to various biotic and abiotic stresses. materials and methodsthis study was conducted at the ardabil agricultural research center to evaluate the effect of two types of fertilizers (iron fertilizer and humic acid) on the yield and phenological traits of two safflower cultivars. this experiment was conducted as a split-plot design based on a completely randomized block design with three replications. the main factor included two safflower varieties named &chini& and &goldasht,& while the sub-factor consisted of nine fertilizer levels. these fertilizer levels included one control level, two levels of 95% humic acid (two milligrams per liter and four milligrams per liter), two levels of 12% edta chelated iron (one milligram per liter and two milligrams per liter), and four combined levels of iron and humic acid fertilizers. results and discussionthe results revealed a significant difference in performance traits between the two varieties, chini and goldasht. observations showed that the goldasht variety produced a significantly higher seed yield of 1,462.5 kg per hectare, compared to 1,403.3 kg per hectare for the chini variety. additionally, the second level of iron + second level of humic acid treatment showed significantly the highest yield, resulting in a 49% increase in seed yield compared to the control. overall, the combined use of these two fertilizers is recommended. the goldasht variety requires a shorter time for flowering and maturity compared to the chini variety and matures earlier while also having a higher yield, making it preferable in this regard. for the traits of plant height and antioxidant activity, there is no significant difference among the cultivars. however, among the fertilizer levels, the second level of humic acid resulted in a height of 68.3 cm, and for antioxidant activity, the combination of the second level of humic acid and the second level of iron exhibited the highest activity at 84.5%. overall, among the cultivars, ’goldasht’ and among the fertilizer levels, the treatment combining the second levels of iron and humic acid had the highest biological yield, the highest harvest index, oilseed yield, and seed yield.  humic acid, due to its nitrogen-like effects and its richness in organic materials, leads to increased seed filling and higher thousand-grain weight. on the other hand, the application of iron helps to cleanse reactive oxygen species and improves the plant’s sink performance, providing more seeds for filling. conclusionthe studies indicated that the goldasht variety matures earlier and yields more than the chini variety. due to its longer growth period, the chini variety is more susceptible to late-season challenges such as heat stress, pests, and bird damage, which can negatively affect yield. therefore, the cultivation of the goldasht variety is preferable in this context. in terms of physiological traits, the application of iron and humic acid fertilizers was found to enhance the stability and resilience of both varieties. the interaction between humic acid and iron proved beneficial for safflower health, promoting greater nutrient uptake, improved growth parameters, increased seed yield, and enhanced stress tolerance.