| چکیده انگلیسی مقاله |
In developing countries, fertilization is one of the most crucial factors in improving agricultural productivity and ensuring food security. In this research, the effect of six treatments (control (distilled water), 1 mM silicon (Si), 2 mM Si, 5 µM selenium (Se), 10 µM Se, and a combination of Si and Se) was evaluated on various traits of Cucurbita pepo under field conditions. In this regard, an experiment was conducted in a randomized complete block design (RCBD) with three replications at the greenhouse farm of the Faculty of Agriculture, Ilam University, in 2023. At the end of the experimental period, various traits, including growth parameters, plant pigments, yield, and several macro- and micronutrients, were measured. The results showed that spraying Si and Se, along with their combination, improved different traits including yield (33-73%), shoot fresh (29-60%) and dry weight (27-56%), 100- seed weight (16-18%), number of fruits per plant (43-59%), oil percentage (18-27%) and oil yield (40-65%) in the treated squash. Furthermore, Si and Se, separately and in combination, significantly increased chlorophyll content (11-20%), carotenoids (33-43%), and Fe2+, Zn2+, K+, and Na+ in the plants. In conclusion, our study demonstrated that foliar spraying with Si and Se can enhance the growth and yield of Cucurbita pepo under field conditions.
Introduction
As one of the essential micronutrients and one of fourteen rare elements effective in human health, Selenium (Se) possesses anti-cancer, anti-aging, and immune-enhancing properties (Azizi et al., 2020). Furthermore, Se is considered an essential component of selenoamino acids, selenoproteins, glutathione peroxidase, and thioredoxin reductase (Hu et al., 2023). To enhance its content in human food, Se has been suggested for use as a chemical fertilizer in crops. Followed by Oxygen (O2), Silicon (Si) is the second most abundant element in the Earth's crust and accounts for 32% of the lithosphere. Si is naturally found in the form of silicates, silicon minerals, or in combination with oxygen or other elements such as aluminum, manganese, calcium, sodium, iron, and potassium. Overall, Si mainly constitutes more than 95% of terrestrial rocks, meteorites, water, and the atmosphere (Trejo-Téllez et al., 2020).
Si plays a considerable role in plant growth and development. In this context, it generally improves seed germination, photosynthetic activity, stomatal conductance, carbon dioxide uptake, gas exchange, leaf turgor, relative water content (RWC), and plant production and yield (Arif et al., 2021). Additionally, Si can influence plant-water relationships, enhance photosynthesis and nutrient uptake, regulate phytohormone biosynthesis and the activity of specific enzymes, and mitigate oxidative stress (Wadas, 2021). Considering the remarkable effects of Si on plant growth and development, this study aimed to evaluate its effects separately and in combination with Se on some growth, physiological, and yield traits of Cucurbita pepo under field conditions.
Materials and Methods
This study was conducted at the Agricultural Faculty of Ilam University, utilizing a randomized complete block design (RCBD) with three replications under field conditions in 2023. To produce seedlings, the seeds of Cucurbita pepo (Hamadan accession) were sown in plastic bags and watered regularly. After two weeks, the two-leaf seedlings were transferred to the experimental field, and then, at the four-leaf stage, they were subjected to a treatment that included foliar spraying repeated four times a day at 10-day intervals. The foliar spraying consisted of distilled water (control), Se (5 and 10 μM), Si (1 and 2 mM), and a combination of Si (2 mM) and Se (10 μM). After fully ripening, the fruit and aerial parts of the plants were transferred to the laboratory for measurement of the traits.
Result and Discussion
The results of this study showed that the application of Si and Se increased the fresh and dry weight of Cucurbita pepo. At low concentrations in wheat, Si has been reported to increase the fresh and dry weights of both the shoot and root (Karimi & Mohsenzadeh, 2016). Previous studies have also documented that respiratory activity in the leaves of Se-treated cabbage was remarkably high, which consequently led to an increase in cabbage yield. Furthermore, it has been demonstrated that Se can enhance the yield of lettuce (Hajiboland & Keivanfar, 2012), which is consistent with our findings regarding growth parameters. In our study, the application of Si and Se increased the number of fruits per plant, as well as the fresh and dry weights, and the yield of Cucurbita pepo.
Researchers have previously stated that the foliar application of Se likely improves yield-related traits by influencing physiological processes (Hemmati et al., 2019). Due to the suitable properties of Se, such as its highly antioxidant activity, Se-treated plants have grown appropriately and gained a remarkable increase in oil content (Hemmati et al., 2019). In addition to improving growth traits, Si and Se enhanced oil percentage and yield of the treated plants (Shahidi et al., 2023), which is in agreement with our findings. Elevating the content of chlorophyll and carotenoids, as well as the amount of nutritional elements such as Fe2+, Zn2+, K+, and Na+, is another beneficial effect of applying these substances to plants. In conclusion, the application of Si (particularly 2 mM) and Se (particularly 5 μM) should be employed to improve growth parameters and yield of Cucurbita pepo under field conditions. |