Foliar Application Of Selenium Research Articles

Exogenous selenium foliar application on nutrition, grain yield and quality of rice (Oryza sativa L.)

Selenium (Se) supplementation through plant-based foods is easy to implement and effective; therefore, it is important to explore the Se-enrichment ability of staple grains and analyze their quality. The purpose of this study was to investigate the effects of foliar application of Se on the quality, Se-enriched capacity, organic Se composition and content of rice under field cultivation. The results showed that exogenous Se application at 80 mg L−1 contributed the most to the yield, and eight elements differed accordingly to the application of Se, promoted the accumulation of Se-containing organic matter in rice grain. This indicates that rational foliar application of Se can effectively improve the quality of rice grains. Moreover, selenomethionine (SeMet), selenocysteine (SeCys2), and Se-methylselenocysteine (Se-MeSeCys) are important components of Se-enriched in hydrolyzed proteins in grains. Based on these results, foliar spraying of Se is a suitable method to supplement rice with additional Se and can improve the yield and quality of rice grains, particularly the quality of organic Se and Se-containing amino acids.

Increased nutritional quality of rice grains and migration mechanisms of selenium by spraying a foliar selenium-rich nutrient solution

Foliar application of selenium (Se) is an effective method for biofortification in rice, to ensure that sufficient Se is supplied by the crop to maintain human health. In order to improve Se concentration in rice and meet the daily recommended intake for humans, a foliar Se fertilizer was applied in five regions of Liaoning and Jilin provinces, China, and its effects on rice quality, leaf morphology, and wax characteristics were assessed in field tests. The effects of alkyl polyglycosides (APG) in the Se fertilizer were evaluated, and epicuticular waxes were measured to analyze the effects of the fertilizer on plant water status. The Se fertilizer effectively enhanced organic Se levels in rice (p < 0.05), ranging from 599.8 to 2002.0 µg kg−1. An intake of 50 g d−1 of Se-enriched rice can meet nutritional requirements, with total Se intake ranging from 30.0 to 100.1 µg d−1. The Se fertilizer increased the protein content and decreased the proportion of chalky rice (p < 0.05). APG increased the wettability of Se fertilizer on the surface of leaves, so Se could be better absorbed into the leaves and accumulate in rice. The Se fertilizer increased the epicuticular wax so that moisture loss from leaves was reduced. Mean cuticular wax thicknesses were 2.36 and 2.25 µg cm2 in Daohuaxiang and Wuyou 4, respectively. These results suggest a link between the quality of rice and epicuticular wax thickness, and the foliar application of Se fertilizer shows promise for increasing Se content in rice grown in Se deficient soils.

Significance of selenium in ameliorating the effects of irrigation deficit via improving photosynthesis efficiency, cell integrity, osmo-protectants, and oil profile of anise crop

Anise is one of the plants with therapeutic potential, which is classified among the most important medicinal plants with interesting biological effects. Its components could be perceived so as “natural” and “safe” alternatives to antibiotics as well as they are applied in different industries such as food and cosmetic purposes. Selenium (Se) is an essential micronutrient, however, its importance to improve oil yield and quality of anise has not been adequately investigated, specifically under drought. Therefore, two successive seasons were conducted to investigate the effect of selenium foliar application upon anise plants under drought stress. Selenium was applied at three different concentrations (0.0 1.0 and 2.0 mM denoted Se0, Se1 and Se2, respectively) along with two levels of crop evapotranspiration (ET): Full irrigation, 100% of ET (FI) and 60% of ET (DI). The promotive effect of combinations of DI × Se1 or Se2 (for Fv/Fm, RWC%, and MSI% in the first season) and DI × Se2 (for Fv/Fm, and MSI% in the second season) were as similar as FI × Se2. Compared to the counterpart control treatment (DI × Se0), the highest increases in total free amino acids (31.5 and 31.6%), total soluble sugars (84.2 and 86.4%) and free proline content (84.2 and 86.4%) were recorded with application of DI × Se2 practice in both seasons, respectively. Under DI, Se2 recorded the maximum values of root length, shoot fresh weight and shoot dry weight in the second season. Under drought, the increases in seed yield due to application of Se1 and Se2 amounted to 1.72 and 1.62 folds in the 1st season and 1.50 and 1.43 folds in 2nd one, respectively. The most effective practice for improving IWUE was Se1× DI in both seasons, followed by Se2 × DI. Based on the chromatographical detection, the maximum values of Anethole were recorded with FI × Se2 while L-Linalool has greatly increased with DI × Se2. In conclusion, the growers in arid and semi-arid zones are advised to use selenium (2.0 mM) in anise fertilization to mitigate the adverse impacts of drought, and keeping crop yield and quality.

Foliar Spray with Selenium to Mitigate the Impact of Water Stress on Chemical, Enzymatic, and Hormonal Parameters of Garlic Allium sativum L.

The current research explored the beneficial role of selenium (Se) in alleviating the negative impacts of water stress on the chemical, enzymatic, and hormonal parameters of garlic plants via manipulating chemo-physiological mechanisms. A field experiment was executed at the research station of the Faculty of Agriculture, University of Kufa, Iraq in September 2022 using a randomized complete block design with three replicates based on a strip-plot system. Three water levels (100%, 80%, and 60%) were set up in the whole plots while foliar application of selenium (Se) with three concentrations (0, 10, and 20) mg.L-1 were assigned to the subplots. Our findings revealed a significant increase in the leaf content of free proline acid, sulfur, and ABA, as well as an increase in the activity of the antioxidant enzymes SOD and CAT when reducing irrigation levels from (100% to 60%) of the water requirement. While there was a significant decline in the plant hormones GA3 and IAA content in garlic leaves @ (60%) level of irrigation. The plants treated with foliar selenium @ (20 mg.L-1) enhanced most of the studied characteristics of garlic plants grown at different water levels. Moreover’ the full water requirement in combination with foliar Se @ (20 mg.L-1) provided the highest values of GA3 and IAA which were both comparable to the interaction treatment of water level @ (80%) and foliar Se @ (20 mg.L-1).

Selenium foliar application contributes to decrease ratio of water-soluble fluoride and improve physio-biochemical components in tea leaves

The tea plant accumulates elevated levels of fluoride (F) from environmental sources. Drinking tea containing high F levels poses a potential threat to human health. Selenium (Se) was applied by foliar spray to investigate its effects on F accumulation and physiology in tea plant. Foliar application of different forms of Se, i.e., Na2SeO3, Kappa-selenocarrageenan, Selenomethionine and Nanoselenium, reduced F content in tea leaves by 10.17 %−44.28 %, 16.12 %−35.41 %, 22.19 %−45.99 % and 22.24 %−43.82 %, respectively. Foliar spraying Se could increase F accumulation in pectin through increasing pectin content and pectin demethylesterification to bind more F in the cell wall, which decreased the proportion of water-soluble fluoride in tea leaves. Application of Se significantly decreased the contents of chromium (39.6 %−72.0 %), cadmium (48.3 %−84.4 %), lead (2.2 %−44.4 %) and copper (14.1 %−44.6 %) in tea leaves. Foliar spraying various forms of Se dramatically increased the Se content and was efficiently transformed into organic Se accounting for more than 80 % in tea leaves. All Se compounds increased peroxidase activity by 3.3 %−35.5 % and catalase activity by 2.6 %−99.4 %, reduced malondialdehyde content by 5.6 %−37.1 %, and increased the contents of chlorophyll by 0.65 %−31.8 %, carotenoids by 0.24 %−27.1 %, total catechins by 1.6 %−21.0 %, EGCG by 4.4 %−17.6 % and caffeine by 9.1 %−28.6 %. These results indicated that Se application could be served as a potential efficient and safe strategy diminishing the concentration of F in tea leaves.

Foliar application of selenium and glycine betaine improve morph-physiological characteristics of peach trees grown under deficit irrigation stress

Foliar application of selenium and glycine betaine improve morph-physiological characteristics of peach trees grown under deficit irrigation stress

Effects of SeNPs Fertilizer on Se and Microelement Contents, Eating and Cooking Qualities, and Volatile Organic Compounds in Rice Grains

Foliar application of selenium (Se) fertilizer has been widely used in the production of Se-rich rice. However, the effect of Se-nanoparticles (SeNPs) fertilizer on rice quality remains largely unknown. Two bioSeNPs fertilizers were applied at different Se concentrations to explore the effect of the foliar application of SeNPs fertilizer on various rice grain qualities. The results showed that Se treatments resulted in 1.93–9.09 and 1.89–7.73 folds of total Se contents in brown and polished rice relative to the CK, respectively. Moreover, the Se treatments led to 1.04–2.33 folds increases in Cd contents, 14.6–26.4% decreases in As contents, a 13.9–16.7% reduction in Cr contents and no changes in Pb contents to that of the CK in rice grains. In addition, SeNPs exhibited no obvious impact on rice eating and cooking quality, and only the XY1 treatment could slightly improve the fatty acid content. Interestingly, Se treatments enhanced the contents of more than half of volatile organic compounds in brown rice. In general, SeNPs fertilizer XY at 6.4 g/ha was identified as the optimum choice for improvement in grain Se contents and grain qualities.

Effects of exogenous selenium application for enhancing salinity stress tolerance in dry bean

Excess salinity is one of the most important abiotic stress that negatively affect plant growth and development. Like many other leguminous crops, dry bean (Phaseolus vulgaris L.), is classified as salt-sensitive plant. Researches related to the use of selenium to reduce salinity stress have been increasing in recent years. However, no study has been found in the world literature that shows the effects of this element on reducing salinity stress in dry bean. The main purpose of this study was to determine whether the negative effects of salinity stress on growth, yield, and organic compounds of dry bean could be reduced by foliar selenium applications. Three different foliar application dosages of selenium (0, 5 and 20 ppm) under four different irrigation water salinity levels (control-0.6, low-1.6, moderate-3.0 and high-4.8 dS/m) were tested in the study. It has been shown that the foliar application of selenium, which is suggested to be used to reduce salinity stress in many plants, did not show, in general, a statistically positive trend for almost all growth, yield, and quality parameters in dry bean. Compared to the control salinity treatment, it was revealed that the application of 20 ppm selenium did not affect the salinity threshold value at a significant level, but this application had a very low positive effect on the slope value, which expresses the decrease in yield after the threshold salinity. In general, it was concluded that foliar application of selenium under studied concentrations had a minor effect than expected in improving the tolerance of salinity stress in dry bean.

Elemental Composition and Implications on Brown Rice Flour Biofortified with Selenium.

Rice (Oryza sativa L.) is one of the most economically and socially important cereals in the world. Several strategies such as biofortification have been developed in a way eco-friendly and sustainable to enhance crop productivity. This study implemented an agronomic itinerary in Ariete and Ceres rice varieties in experimental fields using the foliar application of selenium (Se) to increase rice nutritional value. At strategic phases of the plant's development (at the end of booting, anthesis, and at the milky grain stage), they were sprayed with sodium selenate (Na2SeO4) and sodium selenite (Na2SeO3). In the first foliar application plants were sprayed with 500 g Se·ha-1 and in the remaining two foliar applications were sprayed with 300 g Se·ha-1. The effects of Se in the level of micro and macronutrients in brown grains, the localization of Se in these grains, and the subsequent quality parameters such as colorimetric characteristics and total protein were considered. After grain harvesting, the application of selenite showed the highest enrichment in all grain with levels reaching 17.06 µg g-1 Se and 14.28 µg g-1 Se in Ariete and Ceres varieties, respectively. In the Ceres and Ariete varieties, biofortification significantly affected the K and P contents. Regarding Ca, a clear trend prevailed suggesting that Se antagonizes the uptake of it, while for the remaining elements in general (except Mn) no significant differences were noted. Protein content increased with selenite treatment in the Ariete variety but not in Ceres. Therefore, it was possible to conclude, without compromising quality, that there was an increase in the nutritional content of Se in brown rice grain.

Response of peanut (Arachis hypogaea L.) to potassium, silicon, and selenium foliar application under water stress conditions

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Improving physiological and biochemical responses of dryland canola by selenium foliar application and supplemental irrigation

Improving physiological and biochemical responses of dryland canola by selenium foliar application and supplemental irrigation

The Effect of Selenium Foliar Application on the Physiological Responses of Edamame under Different Water Treatments

Drought has devastating effects on crops, posing enormous risks to food security. This study investigated the impact of foliar applied selenium [at four concentrations (25, 50 and 75 mg/L)] on the photosynthesis capacity, antioxidative enzyme activities [ascorbate peroxidase (APX) and guaiacol peroxidase (GPX)] and yield parameters of a drought susceptible edamame under optimal watering and drought-stressed conditions. The study was conducted in the greenhouse under controlled conditions with leaf sampling done at vegetative, flowering and pod filling stages. Treatment of drought-stressed plants with selenium selectively induced PIabs and chlorophyll content at the vegetative stage. Ascorbate peroxidase was the only parameter induced at the flowering stage by selenium under drought stress. Selenium had no effect on all parameters under drought stress at pod filling, suggesting that the efficacy of selenium declines with time. In addition, yield parameters were not substantially affected by selenium under drought stress. Although selenium was effective for selected parameters, the application should only be limited to edamame growing under drought stress because, under well-watered conditions, it had negative impacts. Future studies should explore the responses drought stressed edamame after secondary application of selenium (i.e., at vegetative, flowering and pod filling).

Diverse Planting Density-Driven Nutrient and Yield Enhancement of Sweet Corn by Zinc and Selenium Foliar Application

Corn (Zea mays L.) is one of the major cereal crops cultivated worldwide. Zinc and selenium are important nutrients for humans and plants, and their deficiency is a cause for concern in most developing countries. Sweet corn fertilized with zinc and selenium can mitigate this problem. Therefore, the objective of this study was to investigate the effects of fertilization with Zn and Se on the yield and quality of sweet corn varieties under different planting densities. The experimental design used was a split-plot based on a randomized complete block design with three replications. Compared to the control, significant differences were recorded in grain yield, leaf area index, and plant height (i.e., Zn/Se + density + variety) treatments. Non-significant differences in the number of kernels per cob, sugar content and crude protein were recorded under different treatments. Significant differences in grain yield, water-soluble sugar, and zinc and selenium content in grain were recorded. Grain yield was higher in Selenium than in Zinc treatments, with a mean difference of 0.05 t ha−1. We conclude that grain yield and selenium content in grain were influenced by selenium foliar application, while water-soluble sugar and zinc content in grain were influenced by foliar zinc application.

Growth and shelf life of basil in response to selenium fertilization

Selenium is essential for human metabolism and its enrichment in vegetables plays an effective role in providing the body with selenium requirements. This factorial experiment was conducted in a greenhouse at Shahrekord University in 2019 to study the effects of selenium on basil growth and shelf life in the conditions of feeding with poultry manure (PM) and chemical fertilizers (CF). Experimental factors included two types of soil amended for plant nutrition (PM and CF) and five selenium concentrations (0, 1.5, 3, 4.5, and 6 mg L − 1) applied as foliar sprays. The results showed that shoot fresh weight in plants receiving PM was 16.6% more than CF fertilizers and foliar application of selenium had no effect on fresh weight. In the PM applied conditions, with the increase of selenium, the chlorophyll b content increased and then decreased. Increasing selenium improved its accumulation in the basil tissue, and the amount of selenium accumulated with poultry manure was more than that accumulated with chemical fertilizer. Whereas, the greatest weight loss in storage was observed in high selenium concentration. In plants receiving PM, increasing concentration of selenium sprays improved the shelf life, then decreased. However, in the amended soil with CF, the shelf life did not change by selenium, except in 1.5 mg L − 1 concentration. It is concluded that the foliar application of moderate amounts of selenium in poultry manure conditions helps to produce more basil, relatively good enrichment of selenium in plant tissue and maintain its optimal quality during the storage.

Effects of Selenium on the Chlorophylls, Gas Exchange, Antioxidant Activity and Amino Acid Composition of Lettuce Grown under an Aquaponics System

Aquaponics is a sustainable technique that is respectful to the environment, as it reuses products and minimizes the consumption of new materials. The combination of this technique with the foliar application of selenium (as Na2SeO4) could lead to healthier and more sustainable products, which are increasingly requested by consumers. Lettuce (Lactuca sativa L.) plants were grown in an aquaponics system (fish water) as compared with a control (conventional soilless fertigation), and sprayed with different concentrations of selenium (0, 4, 8, and 16 µmol L−1). The results showed a reduction in the dry weight and N content of lettuce plants irrigated with the fish water mixture treatment. However, the application of Se relieved this stress, increasing the photosynthetic rate and ABTS, and reducing the content of chlorophylls, β-carotene, and several of the measured amino acids. The best results were observed with the highest concentration of Se (16 µmol L−1), as an increase in nitrogen content was observed, as shown by a greater weight of the plant. Furthermore, this treatment produced the greatest increase in ABTS and the least reduction in amino acid content. This novel study highlights the possibility of improving the efficiency of N utilization in lettuce by applying foliar selenium in combination with an aquaponics system.

Selenium improved antioxidant response and photosynthesis in fragrant rice (Oryza sativa L.) seedlings during drought stress.

Drought stress substantially influences the growth and development of many crops. The present study was conducted to investigate the effects of exogenous selenium on the growth, photosynthesis and antioxidant response of fragrant rice seedlings under drought stress. In a pot experiment, fragrant rice seedlings were subjected to drought stress (soil water potential was controlled at - 0.025 ± 5MPa) and foliar application of selenium (Se) at 0, 10, 30, and 50μmol L-1. Rice seedlings not exposed to drought stress and Se were used as control. Exposure of fragrant rice seedlings to drought stress resulted in significant (P < 0.05) decrease in fresh weight, dry weight, plant height and stem diameter relative to the control. Total chlorophyll, chlorophyll a, chlorophyll b and carotenoid were 20.54-27.24%, 20.82-26.83%, 19.45-29.07% and 21.49-29.17% lower with drought stress treatment compared to CK. Drought stress also significantly (P < 0.05) decreased net photosynthetic rate and soluble protein content. However, Se treatments (30 and 50μmol L-1) substantially improved fresh weight and dry weight of fragrant rice seedlings under drought stress. Net photosynthetic rate, activities of antioxidant enzymes (GPX, SOD and CAT) and soluble protein content in rice seedlings under drought stress improved due to Se treatment. Higher transcript levels of antioxidant-related genes (GPX1, GPX4, CATA and CATC) were also observed with Se treatment.

Effect of foliar application of the selenium-rich nutrient solution on the selenium accumulation in grains of Foxtail millet (Zhangzagu 10).

The foliar application of selenium (Se) is an effective method for biofortification of Se in crop grains in order to provide sufficient Se for human health. As a staple food in China, the foxtail millet (Setaria italica L.), which had been Se biofortification, would be helpful to overcome Se deficiency in the diet. The Se fertilizer and its application technology are vital for reducing environmental risk while enriching selenium. Hence, the Se-rich nutrient solution developed by ourselves was used, and the effect of its amount and growth stage applied on the accumulation of Se in grains of foxtail millet (Setaria italica L.) was studied in the present study. The results were as follows: (1) the Se concentration in grains increased with the Se application rate increasing, and the highest Se concentration in grains was 1.83 mg kg-1 at the sprayed concentration of 61.5 gSe hm-2; (2) the accumulation of Se sprayed in the grain-filling stage was 1.3-1.6 times higher than that in the joint stage; and (3) the organ damage could be found under low Se/S ratio, which happened in the rice leaves when the Se rate was higher than 76.875 gSe m-2 with the low sulfate application compared with the formulation. This Se-rich nutrient solution could be used to produce the Se-rich millet grains and foliar application in the reproductive stage to produce qualified Se-rich millet.

Selenium Fortification Alters the Growth, Antioxidant Characteristics and Secondary Metabolite Profiles of Cauliflower (Brassica oleracea var. botrytis) Cultivars in Hydroponic Culture.

Nowadays the importance of selenium for human health is widely known, but most of the plants are poor in terms of selenium storage and accumulation because of the low selenium mineralization potential of the soil. For this purpose, foliar application of different sodium selenate concentrations (0, 5, 10, 15, 20 mg/L) was used to treat the cauliflower cultivars “Clapton” and “Graffiti”. Higher yields and other related vegetative attributes were improved at 10 and 15 mg/L sodium selenate application. At a concentration of 10 mg/L sodium selenate, photosynthetic pigments, total phenolic compounds and antioxidant capacity were enhanced in both cultivars, but the “Graffiti” cultivar responded stronger than the “Clapton” cultivar. The glucosinolates were accumulated in response to selenium fortification and the highest amounts were found in the “Graffiti” cultivar at 10 mg/L. Selenium accumulated concentration-dependently and rose with higher fertilization levels. In general, foliar application of selenium at 10 mg/L led to an accumulation of secondary metabolites and also positively affected the growth and yield of florets.

Influence of organic manures and biofortification of selenium on growth, yieldand selenium contentof cucumber (Cucumis sativus L.)

Field experiment was conducted to study the influence of organic manures and biofortification of selenium on growth, yield and selenium contentof cucumber (CucumissativusL.) during 2019 at Koneripalayam village in Perambalur district, Tamil Nadu. The popular variety Green Long suitable for this region was used for the present study. The experiment was carried out during two seasonsviz., Season I (February-May) and Season II (July-October)in randomised block design with fifteen treatments and three replications. The results of the experiment revealed that application of 25 tFYM ha -1 and 2 kg CBF ha -1 along with foliar application of Se (20 µg L-1) significantly recorded the highest vine length (209.1 cm and 214.6 cm), number of leaves (108.2 and 113.7), leaf length (15.7 cm and 15.9 cm) and leaf breadth (16.2 cm and 16.5 cm) in first and second season, respectively. The highest number of fruits per vine (13.3 and 16.5), fruit length (19.6 cm and 20.8 cm), fruit girth (17.1 cm and 18.2 cm), mean single fruit weight (78.1 g and 81.2 g), fruit yield vine-1 (723.5 g and 1009.2 g)and selenium content per fruit (8.1 µg kg-1 and 10.6 µg kg-1) in first and second season respectively was obtained with1 t EM ha -1 + 2 kg CBF ha -1 + Se (20 µg L-1) as foliar application. Among all the organic manures, farmyard manure was proved to be superior in respect of growth parameters and enriched manure in respect of yield parameters. The foliar application of selenium was found to be the best method of its supplementation in plants and relatively higher values of Se content in fruits were noted with higher dose of Se as folior application.

Effects of biochar and foliar application of selenium on the uptake and subcellular distribution of chromium in Ipomoea aquatica in chromium-polluted soils

The potential toxicity of Cr to plants poses a severe threat to human health. Biochar and Se can reduce the absorption of Cr and its phytotoxicity in plants, but the associated mechanisms at subcellular levels have not been addressed in depth. A study was designed to investigate the effects of biochar, foliar application of Se, and their combination on the physicochemical and biological properties of the soil, Cr availability, Cr absorption, and Cr subcellular distribution in each part of the plant, and biomass and quality of two water spinach (Ipomoea aquatica) genotypes. The results showed that biochar, Se, and their combination increased the organic matter content and available NPK nutrients in the soil and improved the urease, phosphatase, catalase, and sucrase activities in the soil. Furthermore, they also increased the number of bacteria, actinomycetes, and fungi in the soil, were conducive to dry matter accumulation in I. aquatica, and increased the contents of soluble sugar and soluble protein in its leaves. The Cr contents in the roots and shoots of I. aquatica under different treatments were reduced compared with those in the control group. The content of Cr(VI) in the root-soil of I. aquatica with low Cr accumulation and the contents of Cr in various parts of I. aquatica were lower than those in I. aquatica with high Cr accumulation, and the absorbed Cr was mainly accumulated in the roots. Cr was mainly distributed in the cell walls and soluble fractions of the roots, stems, and leaves of I. aquatica and was less distributed in the organelles. Biochar and Se helped to increase the proportion of Cr in the cell walls of the roots and soluble fractions of the leaves of I. aquatica. The effects of improving the soil properties, passivating and inhibiting Cr absorption by I. aquatica, and reducing the Cr proportion in the organelles of biochar were superior to those of Se application. The foliar application of Se and biochar had no synergistic effect on inhibiting Cr absorption by I. aquatica. Based on these findings, the application of biochar in Cr-contaminated soil or foliar application of Se with low Cr-accumulating plants may be effective means of reducing the Cr absorption by plants and its toxicity to ensure the safe production of agricultural products in Cr-contaminated regions.