اثر کاربرد خاکی سولفات منیزیم بر خصوصیات کمی و کیفیت میوه نخل خرما (.phoeix dactylifera l) رقم مضافتی

منیزیم از جمله عناصر غذایی موثر بر عملکرد، کیفیت و طعم میوه خرما است. در این پژوهش، اثر کاربرد خاکی سولفات‌منیزیم (mgso4.7h2o) بر خصوصیات کمی و کیفیت میوه نخل خرما رقم مضافتی در قالب طرح بلوک‌های کامل تصادفی با سه تکرار و چهار تیمار (0، 250، 500 و 750 گرم سولفات‌منیزیم به‌صورت کاربرد خاکی در هر درخت)، بر روی 12 نفر نخل خرمای 20 ساله رقم مضافتی در دو سال زراعی (1401 و1402) در نخلستانی در بروات از توابع شهرستان بم در استان کرمان بررسی شد. نتایج نشان داد اثر سطوح تیمار سولفات‌منیزیم بر عملکرد میوه درخت، قطر میوه، میزان مواد جامد محلول کل ((tss خرما و غلظت منیزیم در برگ در سطح احتمال یک درصد و بر طول هسته خرما در سطح احتمال پنج درصد معنی‌دار بود. بیشترین عملکرد میوه درخت (74/66کیلوگرم در درخت)، بیشترین قطر میوه (2/31سانتی‌متر) و بالاترین مقدار tss میوه (33/66 درصد) مربوط به تیمار سولفات منزیم به میزان 250 گرم در هر درخت بود. بیشترین میزان منیزیم در برگ (0/1883درصد) و کمترین طول هسته (1/98سانتی‌متر) در تیمار 750 گرم سولفات منیزیم ثبت شد. این یافته‌ها نقش حیاتی سولفات‌منیزیم را در بهینه‌سازی بهره‌وری عملکرد و کیفیت میوه نخل خرما رقم مضافتی برجسته کرده و بر ضرورت مدیریت مناسب و بهینه کودهای دارای عنصر منیزیم در نخلستان های منطقه تاکید می کند. بنابراین، استفاده بهینه از سولفات‌منیزیم می‌تواند به عنوان راهکاری عملی جهت ارتقاء کمیت و کیفیت میوه خرما رقم مضافتی مورد بهره‌برداری قرار گیرد.

effect of soil application of magnesium sulfate on fruit quantitative and quality characteristics of date palm (phoeix dactylifera l.) cv. mazafati

to investigate the effects of different magnesium sulfate on fruit quantitative and quality characteristics of date palm (phoeix dactylifera l.) cv. mazafati, a field experiment was carried out using randomized complete block design with three replications in palm date orchard cv. mazafati in baravat district of bam, kerman province, in iran, in two growing seasons (2022 and 2023). the experimental treatments were four levels (0, 250, 500, and 750 g tree-1) of soil applied magnesium sulfate. the results showed that magnesium sulfate levels had significant effect on fruit yield, fruit diameter, seed length, total soluble solids (tss), and leaf magnesium content. the 250 g level had the highest fruit yield and quality, while the 750 g level showed the highest leaf magnesium content. in conclusion, soil application of magnesium sulfate improved fruit yield, fruit quality and pomological traits. the results underlined the importance of megensium role in improvement of productivity and fruit quality of date palm trees cv. mazafati. keywords: date palm, orchard, fruit diameter, pomological traits, fruit yield.  introductionin recent years, numerous studies have investigated the role of magnesium in improving plant growth, yield, and fruit quality. tränkner et al. (2019) highlighted the importance of magnesium in biomass production and chlorophyll synthesis. similarly, research by assis (2024) emphasized the role of magnesium in enhancing plant tolerance to abiotic stresses. in most of these studies, the effects of soil-applied magnesium were examined (zhang et al., 2021). unlike previous research, which mainly focused on other fruit crops, this study specifically assesses the effects of different levels of soil applied magnesium sulfate on the fruit quantitative and quality characteristics of date palm cv. mazafati under the climatic conditions of kerman province.this study aimed to determine the optimum level of soil application of magnesium sulfate levels to improve fruit yield and quality traits of date palms cv. mazafati in arid and semi-arid regions in iran. materials and methodsthis research was carried out in two phases. first, the nutritional status of 15 cv. mazafati date palm orchards in kerman province (baravat, bam, shahdad, fahraj, rigan, narmashir, anduhjerd, and chahar-farsakh) was assessed. leaf samples were analyzed for nitrogen, phosphorus, potassium, calcium, and magnesium. data were processed in mean comparisons.second, the main field experiment was carried out in two growing seasons (2022 and 2023) in baravat district, bam, kerman province, in iran, on 20-year-old date palm trees cv. mazafati using randomized complete block design with three replications and four soil applied magnesium sulfate levles 0 (control), 250, 500, and 750 g mgso₄ tree-1. routine orchard management practices were uniformly applied. at harvest, fruit yield tree-1, fruit weight, fruit diameter, seed length, fruit flesh: seed ratio, and total soluble solids (tss) were measured. leaf mg content was determined by complexometric titration. combined analysis of variance and mean comparision lsd tests at the 5% probability level was perfermed using spss (version 26) software. results and discussionthe results showed that despite non-significant differences in nitrogen and phosphorus contents between the control and experimental date palm orchards, potassium and calcium levels were higher, while magnesium levels were lower in the experimental orchards compared to the control. in 85% of the leaf samples, leaf magnesium contents were lower than normal thresholds, which could potentially reduce fruit yield and quality. the higher potassium contents likely inhibited magnesium uptake in the experimental orchard (zhang et al., 2021).soil application of 250 g magnesium sulfate tree-1 resulted in the highest fruit yield (74.66 kg tree-1) and fruit diameter (2.31 cm). this treatment also had the highest tss content (66.33%). however, excessive magnesium sulfate application (500 and 750 g tree-1) led to reduction in tss, likely due to disturbances in cation balance and the uptake of other nutrient elements. our findings are in consistent with the findings of wang et al. (2021).therefore, balanced soil applied magnesium sulfate was effective in correcting nutrient deficiencies and improving fruit yield and quality characteristics of date palm cv. mazafati. referencesassis, v.c.s.s. 2024. magnesium dynamics in the soil-plant system and its role in plant metabolism and nutrition: a review. scientific electronic archives, 17(4), pp.1-10. doi: 10.36560/17420241898tränkner, m. and jaghdani, s.j. 2019. minimum magnesium concentrations for photosynthetic efficiency in wheat and sunflower seedlings. plant physiology and biochemistry, 144, pp.234-243. doi: 10.1016/j.plaphy.2019.09.040wang, z., hassan, m.u., nadeem, f., wu, l., zhang, f. and li, x. 2020. magnesium fertilization improves crop yield in most production systems: a meta-analysis. frontiers in plant science, 10, 495191. doi: 10.3389/fpls.2019.01727zhang, s.w., yang, w.h., muneer, m.a., ji, z.j., tong, l. and zhang, x. 2021. integrated use of lime with mg fertilizer significantly improves the pomelo yield, quality, economic returns and soil physicochemical properties under acidic soil of southern china. scientia horticulturae, 290, 110502. doi: 10.1016/j.scienta.2021.110502