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Iodine (I) is a beneficial micronutrient for crop plants and essential for human health, yet approximately two billion people worldwide suffer from I deficiency, resulting in significant health issues. Agricultural soils often lack sufficient I, resulting in crops with low I content. However, tomatoes have shown potential to accumulate I when supplemented externally, making them an ideal candidate for I biofortification, particularly as an alternative to iodized salt for individuals on low-sodium diets. This two-year greenhouse pot experiment evaluated the effectiveness of foliar application of potassium iodide (KI) in biofortifying two commercial tomato hybrids. Different concentrations of I (0, 1, 3, 6, and 9 mM/plant) were applied as foliar treatments to assess their effects on physiological parameters, yield attributes, and quality traits, especially I enrichment in tomato fruit. The results demonstrated that foliar application of KI significantly increased fruit I contents at concentrations that also promoted overall plant growth and development. These findings underscored the efficient translocation of I through the phloem in tomatoes. I enrichment in tomato fruits ranged up to 5.27 mg/kg, exceeding the recommended daily allowance (RDA) of 150 μg/day. Even lower doses of 1–3 mM KI were effective in achieving significant I enrichment suitable for biofortification programs. In conclusion, tomato emerged as an excellent candidate for agronomic biofortification with I due to the practicality, and affordability of foliar application. The study highlights the potential of foliar I application as a feasible strategy for addressing global I deficiency, emphasizing its suitability for widespread adoption by farmers. [ABSTRACT FROM AUTHOR]

Inherently low concentrations of zinc (Zn), iron (Fe), iodine (I), and selenium (Se) in wheat (Triticum aestivum L.) grains represent a major cause of micronutrient malnutrition (hidden hunger) in human populations. Genetic biofortification represents a highly useful solution to this problem. However, genetic biofortification alone may not achieve desirable concentrations of micronutrients for human nutrition due to several soil- and plant-related factors. This study investigated the response of genetically biofortified high-Zn wheat genotypes to soil-applied Zn and foliarly applied Zn, I, and Se in India and Pakistan. The effect of soil-applied Zn (at the rate of 50 kg ha−1 as ZnSO4·7H2O) and foliar-applied Zn (0.5% ZnSO4·7H2O), I (0.04% KIO3), Se (0.001% Na2SeO4), and a foliar cocktail (F-CT: combination of the above foliar solutions) on the grain concentrations of Zn, I, Se, and Fe of high-Zn wheat genotypes was investigated in field experiments over 2 years. The predominantly grown local wheat cultivars in both countries were also included as check cultivars. Wheat grain yield was not influenced by the micronutrient treatments at all field locations, except one location in Pakistan where F-CT resulted in increased grain yield. Foliar-applied Zn, I, and Se each significantly enhanced the grain concentration of the respective micronutrients. Combined application of these micronutrients was almost equally effective in enhancing grain Zn, I, and Se, but with a slight reduction in grain yield. Foliar-applied Zn, Zn+I, and F-CT also enhanced grain Fe. In India, high-Zn genotypes exhibited a minor grain yield penalty as compared with the local cultivar, whereas in Pakistan, high-Zn wheat genotypes could not produce grain yield higher than the local cultivar. The study demonstrates that there is a synergism between genetic and agronomic biofortification in enrichment of grains with micronutrients. Foliar Zn spray to Zn-biofortified genotypes provided additional increments in grain Zn of more than 15 mg kg−1. Thus, combining agronomic and genetic strategies will raise grain Zn over 50 mg kg−1. A combination of fertilization practice with plant breeding is strongly recommended to maximize accumulation of micronutrients in food crops and to make significant progress toward resolving the hidden hunger problem in human populations. [ABSTRACT FROM AUTHOR]

Selenium (Se) is an essential element for humans. However, much of the world's human population is deficient in this element, which has become a public health problem. This study aimed to evaluate whether applying severe water stress to wheat plants (Triticum aestivum L.) could allow Se to reduce the production losses and increase the grain quality, thereby contributing to the reduction in hidden hunger. The experiment was conducted in a randomized block design with four replications in a 5 × 2 factorial scheme, with five doses of Se (0.00, 0.25, 0.50, 1.00, and 2.00 mg dm−3) and two irrigation conditions (with and without water deficit). When sodium selenate (Na2SeO4) was applied to the soil, the grains were rich in Se. Under low doses, there was an enrichment of the grains in sulfur, iron, copper, and zinc as well as total free amino acids and total soluble proteins, and lower losses in productivity under severe water stress. Higher doses decreased the concentration of malondialdehyde (MDA) and hydrogen peroxide (H2O2), increased the catalase activity, and increased the water use efficiency (WUE). Therefore, applying Se at a dose of 0.25 mg dm−3 is effective for the biofortification of wheat grains. It enhances grain nutritional quality, increases Se bioaccessibility, and reduces production losses under water stress conditions. [ABSTRACT FROM AUTHOR]

Highlights: What are the main findings? Foliar Zn applications are highly effective in biofortified potato clones compared with non-biofortified varieties. Foliar Zn applications do not affect the high iron content in potato tubers. What is the implication of the main finding? Biofortification offers a practical and cost-effective approach to addressing global malnutrition. Given the widespread micronutrient deficiencies in vulnerable populations, crop biofortification has been proposed as a solution to increase nutrient concentrations. This study aimed to determine the effect of combining biofortification strategies on the agronomic characteristics and nutritional composition of potato. The effect of foliar fertilization (FF) with zinc (Zn) on five potato genotypes (G): four biofortified clones developed through conventional breeding with different Zn levels (high, medium, and low in Zn, and one high in Fe and Zn) and a commercial variety ('Yungay') were evaluated. At harvest, the number of tubers per plant, the weight of tubers per plant, and the average tuber weight were evaluated as yield components, and tuber samples were collected for micronutrient determination. For yield components, the analysis with linear mixed models showed no significant G × D interaction effects, but highly significant differences were observed among G. The Zn concentration in tubers showed a highly significant effect in the G × D interaction. The simple effects analysis showed that biofortified genotypes responded to FF with Zn by significantly increasing the tuber Zn concentrations by an average of 43% (range 28–61%), despite growing in alkaline soils. In contrast, the 'Yungay' variety showed a 6% increase. Clones biofortified through conventional genetic improvement responded better to agronomic FF with Zn compared to the non-biofortified commercial variety, demonstrating that both are synergistic strategies that can achieve a significant increase in Zn concentrations in tubers. The result of this study might be used to further biofortification efforts and decrease nutritional deficiencies. [ABSTRACT FROM AUTHOR]

Calcium (Ca) is a vital nutrient essential for structural development and signal transmission in both plants and animals. In humans, inadequate calcium intake has been correlated with various diseases, including osteoporosis, cardiovascular and cerebrovascular diseases, and cancer. In areas where plants serve as a main dietary source, calcium intake is significantly lower than the recommended adequate intake, notably in low‐ and middle‐income countries (LMICs). Exploring the connections between calcium consumption and cardiovascular disease (CVD) and cancer has significant implications for public health, given that these two conditions are the primary contributors to global mortality. This study conducted a systematic review of existing literature to assess the evidence regarding calcium intake and its effect on blood pressure control, stroke prevention, and the controversial association with myocardial infarction. Furthermore, the preventive effect of calcium intake on tumor development, particularly in cancer prevention, was discussed. The study explores the potential of agronomic biofortification as a key strategy to enhance plant‐based dietary calcium density and improve human health. By advocating for the incorporation of calcium‐rich plants and plant‐derived products, alongside appropriate calcium supplementation, the study emphasizes the economic and practical benefits of plants as a calcium source. This approach is aligned with global dietary patterns and socioeconomic disparities. The review also highlights the need for further research to better understand the mechanisms through which agronomic biofortification can increase dietary calcium intake and reduce the risks of CVD and cancer associated with calcium deficiency. Ultimately, this study aims to deepen our understanding of the complex relationship between calcium intake and health. [ABSTRACT FROM AUTHOR]

Human Zn and Fe deficiencies can be reduced through agronomic biofortification, but information on factors influencing maize grain-Zn and -Fe levels remain scanty. This analysis: (1) Establishes the global distribution of Zn and Fe concentrations in maize grain; (2) assess the contribution of different agronomic practices to the effectiveness of Zn fertilizers for increasing grain yields, and Zn and Fe levels in maize grain; and (3) identify key biophysical factors and metrics to more effectively guide agronomic biofortification of Zn. Using 5874 data points in 138 published papers from 34 countries, we estimated a 7.5% probability of grain-Zn concentrations exceeding the benchmark target of 38 mg kg−1. Using 3187 data points from 65 studies across 27 countries we estimated a 8.5% probability of grain-Fe concentrations exceeding the target of 60 mg kg−1. Our 70-paper meta-analysis revealed that applying Zn and/or Fe in combination with inorganic NPK fertilizer can increase maize-grain-Zn and-Fe concentrations by 31% (p < 0.01) relative to the control (NPK only). In 52% and 37.5% of the studies respectively, grain-Zn and -Fe levels showed significant and concomitant increase with grain-yield increases. Soil organic matter, pH, soil-available Zn, organic input applications, and N, Zn and Fe application rates and methods were among the key factors influencing grain Zn and Fe. We conclude there is substantial room for increasing maize-grain Zn and Fe concentrations, and applying Zn, especially in combined soil and foliar applications, gives substantial increases in grain-Zn and -Fe concentrations. This global review reveals large data gaps on maize-grain nutrient levels, and we call for routine collection of such information in future research. [ABSTRACT FROM AUTHOR]

To better understand the effects of agronomic practices on yield–nutrition relationships in wheat (Triticum aestivum L.) grains for Zn biofortification while improving yields simultaneously, effects of different soil fertilization and different drone-based foliar spraying treatments were investigated in calcareous soils. For soil fertilization, the incorporation of Zn or increasing the N/P ratio in compound fertilizers proved to be effective in enhancing grain Zn concentrations and yields. However, the overall effects of soil fertilization are limited, with a maximal yield increase of only 7.0% and a maximal increase of the grain Zn concentration from 19.4 to 27.0 mg/kg, which is far below the target biofortification value of 40–50 mg/kg. Unfortunately, there was a negative side effect, which decreased Fe and Mn concentrations and the Fe bioavailability. Notably, drone-based foliar Zn sprayings increased grain yields from the control 7.5 t/ha to 8.6 t/ha at ZnO treatment by 12.0% and 8.8 t/ha at ZnSO4·7H2O treatment by 17.3%. Meanwhile, grain Zn concentrations were increased from the control 33.5 mg/kg to 41.9 mg/kg at ZnO treatment by 25.1% and 43.6 mg/kg at ZnSO4·7H2O treatment by 30.1%. Treatments with ZnSO4·7H2O increased grain Zn concentrations and accumulation more so than ZnO, indicating the importance of chemical Zn forms in determining the effectiveness of foliar spraying. Moreover, foliar Zn sprayings simultaneously increased grain concentrations and accumulation of Fe, Mn and Cu, demonstrating multiple benefits. There were positive correlations between Zn and Fe, Mn or Cu, indicating synergistic interactions. Compared to micronutrients, concentrations of grain macronutrients (N, P, K, Ca and Mg) were less affected. Thus, a dual-benefit in both grain yields and micronutrient (particularly for Zn) nutrition could be effectively achieved through appropriate soil fertilization and foliar Zn spraying. These findings provide a better understanding of the yield–nutrition relationship among wheat grain yields, Zn and other nutrient elements for a better integrated manipulation to achieve a win–win situation in yield and nutrition. [ABSTRACT FROM AUTHOR]

Inherently low concentrations of zinc (Zn), iron (Fe), iodine (I), and selenium (Se) in wheat (Triticum aestivum L.) grains represent a major cause of micronutrient malnutrition (hidden hunger) in human populations. Genetic biofortification represents a highly useful solution to this problem. However, genetic biofortification alone may not achieve desirable concentrations of micronutrients for human nutrition due to several soil- and plant-related factors. This study investigated the response of genetically biofortified high-Zn wheat genotypes to soil-applied Zn and foliarly applied Zn, I, and Se in India and Pakistan. The effect of soil-applied Zn (at the rate of 50 kg ha−1 as ZnSO4·7H2O) and foliar-applied Zn (0.5% ZnSO4·7H2O), I (0.04% KIO3), Se (0.001% Na2SeO4), and a foliar cocktail (F-CT: combination of the above foliar solutions) on the grain concentrations of Zn, I, Se, and Fe of high-Zn wheat genotypes was investigated in field experiments over 2 years. The predominantly grown local wheat cultivars in both countries were also included as check cultivars. Wheat grain yield was not influenced by the micronutrient treatments at all field locations, except one location in Pakistan where F-CT resulted in increased grain yield. Foliar-applied Zn, I, and Se each significantly enhanced the grain concentration of the respective micronutrients. Combined application of these micronutrients was almost equally effective in enhancing grain Zn, I, and Se, but with a slight reduction in grain yield. Foliar-applied Zn, Zn+I, and F-CT also enhanced grain Fe. In India, high-Zn genotypes exhibited a minor grain yield penalty as compared with the local cultivar, whereas in Pakistan, high-Zn wheat genotypes could not produce grain yield higher than the local cultivar. The study demonstrates that there is a synergism between genetic and agronomic biofortification in enrichment of grains with micronutrients. Foliar Zn spray to Zn-biofortified genotypes provided additional increments in grain Zn of more than 15 mg kg−1. Thus, combining agronomic and genetic strategies will raise grain Zn over 50 mg kg−1. A combination of fertilization practice with plant breeding is strongly recommended to maximize accumulation of micronutrients in food crops and to make significant progress toward resolving the hidden hunger problem in human populations.

Selenium is an essential trace element in the human body. However, its intake is generally low. Therefore, the production and utilisation of selenium-enriched foods is currently a research hotspot. In this study, the effects of low (0.2 mg·kg−1), medium (1.0 mg·kg−1), and high (5.0 mg·kg−1) concentrations of selenium on the physiological and biochemical characteristics of rice were investigated to develop selenium-enriched rice. High concentrations of selenium have been found to inhibit the growth, physiology, and biochemistry of rice, while low concentrations of selenium promote its growth. The height of mature rice plants exposed to high concentrations of selenium was reduced by 7.20% compared with the height of control rice. Selenium decreased the proline content of rice during the growth period except in mature rice treated with medium and high concentrations of selenium. Excluding high concentrations, selenium treatment increased the soluble sugar content of rice from the tillering to the mature stages. The peroxidase activity of rice at the heading stage treated with medium levels of selenium was significantly higher than that of the control rice, while the superoxide dismutase activity of rice exposed to selenium was significantly enhanced at the mature stage. The malondialdehyde levels of mature rice treated with medium and high levels of selenium were significantly lower than those of the control rice. The selenium content of each plant part was significantly correlated with the soil selenium level. An increase in the soil selenium level facilitated the production of selenium-enriched rice. [ABSTRACT FROM AUTHOR]

Lithium (Li) intake is insufficient in many countries of the world. Low dietary intake of Li is associated with many psycho-behavioral disorders (e.g., increased suicide and homicide rates, aggressive behaviors, unipolar/bipolar disorders, and acute mania). Agronomic biofortification is a good strategy to increase Li intake in the human diet. This study aims to evaluate the effect of Li foliar application on the biofortification of two lettuce cultivars, as well as its influence on morpho-physiological characteristics and elemental composition. The experiment was carried out in a randomized complete block design in a 2 × 5 factorial scheme with four replicates. Two curly lettuce cultivars (SVR 2005 and Solaris) were treated with five levels of Li (0, 16, 32, 48, and 64 g ha−1) applied via foliar under semi-controlled conditions. Both cultivars showed higher Li content and accumulation with the application of 64 g ha−1of Li. For the Solaris cultivar, the supply of 37 g ha−1of Li guarantees the consumption of approximately 30% of the daily Li recommendation. The morpho-physiological characteristics of the Solaris and SVR 2005 cultivars presented positive results with the application of between 20 and 41 g ha−1of Li. The content of potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) was altered by the foliar application of Li. The results obtained in this study show that the application of Li via leaves, under semi-controlled conditions, is an efficient strategy to biofortify lettuce and provide Li in the human diet. However, attention must be paid to the contents of macro and micronutrients in lettuce. [ABSTRACT FROM AUTHOR]

The biofortification of edible crops with selenium (Se) is a common and effective strategy to address inadequate Se intake, which is suffered by millions of people worldwide. However, there is little information regarding the effects of this practice on crops belonging to the important Brassica family. To evaluate the efficacy of foliar Se application on broccoli, four treatments with varying Se concentrations were tested: 0%, 0.05%, 0.10%, and 0.15% (w/v), applied as sodium selenate during the early flowering stage. Although no overall effects on growth and biomass parameters were observed, the results indicate that the lowest Se dose (0.05-Se) was sufficient to notably increase Se concentration in the florets, even after boiling. Based on the increase to 14.2 mg Se kg−1 of dry matter in this broccoli fraction, it was estimated that consuming a 100-gram portion of boiled florets biofortified with 0.05% Se would provide approximately 140 µg of Se, which could be sufficient to potentially improve human selenium status, as previously documented. Moreover, the results obtained underscore how the application of this small dose was also adequate to reduce phytate concentration in the florets and to increase antioxidant and polyphenol concentrations, thereby improving the concentration and bioavailability of other essential nutrients, including Ca, Mg, Fe, and Zn, along with improving its quality as an antioxidant food. [ABSTRACT FROM AUTHOR]

Zinc (Zn) deficiency represents a significant global concern, affecting both plant and human health, particularly in regions with Zn-depleted soils. Agronomic biofortification strategies, such as the application of Zn fertilizers, offer a cost-effective approach to increase Zn levels in crops. This study aimed to assess the efficacy of soil and foliar Zn biofortification, applied as an aqueous solution of 0.5% zinc sulphate (ZnSO4·7H2O), on triticale (x Triticosecale) grown under Mediterranean conditions. The study was conducted over two growing seasons (2017/18 and 2018/19) in southern Spain, evaluating the effects on biomass yield; forage quality, including crude protein, Van Soest detergent fiber, organic matter digestibility, and relative forage value; and nutrient accumulation. Soil treatment consisted in the application of 50 kg of ZnSO4·7H2O ha−1 solely at the beginning of the first campaign to assess the residual effect on the second year. In contrast, the foliar treatment consisted of two applications of 4 kg of ZnSO4·7H2O ha−1 per campaign, one at the beginning of tillering and the other at the appearance of the first node. The foliar application increased the Zn content of the forage to adequate levels, while the soil application resulted in a 33% increase in biomass production, which is particularly beneficial for farmers. Overall quality was favored by the combined soil + foliar application, and no adverse antagonistic effects on other nutrients were detected. Instead, a synergistic interaction between Se and Zn was observed, which improved the efficacy of this important micronutrient for livestock and human wellbeing. [ABSTRACT FROM AUTHOR]

Zinc (Zn) deficiency is a major public health issue worldwide. The biofortification of Zn in popular vegetables could be a promising way to address this burning issue. To enrich tomatoes with bioavailable Zinc through agronomic biofortification. Seven tomato varieties were examined to identify the best one for Zn biofortification based on fruit Zn concentrations. Then six levels of Zn viz., 0, 2, 3, 4, 5, and 6 kg ha−1 were applied to screen out the best Zn dose for maximum biofortification. Finally, the identified Zn dose was applied using six strategies viz., 100% seedling priming, 50% soil + 50% foliar spray at seedling stage, 50% seedling priming + 50% foliar spray, 100% foliar spray at seedling stage, 100% foliar spray at flowering stage and 100% foliar spray at the fruiting stage to recognize the best application strategy. These three experiments were executed following a completely randomized design with three replications. In screening, BARI Tomato-14 showed the lowest Zn concentration compared to all other varieties. The application of 5 kg Zn ha−1 showed the highest Zn concentration in tomato with better yield and quality. Finally, 5 kg Zn ha−1 as 50% soil application + 50% foliar spray showed the maximum biofortification of Zn in BARI Tomato-14 with the highest growth, yield and quality. Therefore, application of 5 kg Zn ha−1 as 50% soil and 50% foliar spray on BARI tomato-14 could be a potential option to mitigate Zn deficiency. [ABSTRACT FROM AUTHOR]

Nanotechnology has been increasingly used in plant sciences, with engineered nanoparticles showing promising results as fertilizers or pesticides. The present study compared the effects in the foliar application of Se nanoparticles (SeNPs) or sodium selenite-Se(IV) on rice seedlings. The degree of plant growth, photosynthetic pigment content, and concentrations of Se, Na, Mg, K, Ca, Mn, Co, Cu, Zn, As, Cd, and Pb were evaluated. The results showed that the application of SeNPs at high concentrations (5 mg L−1), as well as the application of Se(IV), inhibited plant growth and increased the root concentrations of As and Pb. The application of SeNPs at 0.5 mg L−1 significantly increased Se accumulation in the aerial part from 0.161 ± 0.028 mg kg−1 to 0.836 ± 0.097 mg kg−1 without influencing physiological, chemical, or biochemical parameters. When applied to leaves, SeNPs tended to remain in the aerial part, while the application of Se(IV) caused a higher Se translocation from the shoots to the roots. This study provides useful information concerning the uptake, accumulation, and translocation of different Se formulations in rice seedlings and their effect on plant ionomic profiles, thus showing that the foliar application of SeNPs at low concentrations can be an effective and safe alternative for rice biofortification. [ABSTRACT FROM AUTHOR]

Selenium (Se) is an essential element for humans. However, much of the world’s human population is deficient in this element, which has become a public health problem. This study aimed to evaluate whether applying severe water stress to wheat plants (Triticum aestivum L.) could allow Se to reduce the production losses and increase the grain quality, thereby contributing to the reduction in hidden hunger. The experiment was conducted in a randomized block design with four replications in a 5 × 2 factorial scheme, with five doses of Se (0.00, 0.25, 0.50, 1.00, and 2.00 mg dm−3) and two irrigation conditions (with and without water deficit). When sodium selenate (Na2SeO4) was applied to the soil, the grains were rich in Se. Under low doses, there was an enrichment of the grains in sulfur, iron, copper, and zinc as well as total free amino acids and total soluble proteins, and lower losses in productivity under severe water stress. Higher doses decreased the concentration of malondialdehyde (MDA) and hydrogen peroxide (H2O2), increased the catalase activity, and increased the water use efficiency (WUE). Therefore, applying Se at a dose of 0.25 mg dm−3 is effective for the biofortification of wheat grains. It enhances grain nutritional quality, increases Se bioaccessibility, and reduces production losses under water stress conditions.

Abstract The objective of this work was to verify if the nutrients sulfur and nitrogen, once applied to wheat through the process of agronomic biofortification, contribute to the formation of proteins and sulfur amino acids, increasing, consequently, the strength of semolina wheat flour and its ability to form gluten. The chemical, colorimetric, rheological, and enzymatic analyses of biofortified and non-biofortified semolina wheat flour were carried out and submitted to analysis of variance. Regarding the color, there was no difference among the samples, which present a light color. The average protein value was appropriate in both flours, with an average content of 11.32g 100g-1. The wet gluten, the dry gluten, and the content of sulfur amino acids also did not present significant differences among the samples. According to the alveography analysis, the samples presented differences in the analyzed parameters. Among the quality characteristics measured through the farinography, the falling number and the valorimeter value were lower in the biofortified sample, indicating that it weakens quicker throughout the mixture process. The enzymatic activity of the flours were different between them. The semolina wheat flours studied are classified as improver what. With the obtained results, it will be necessary the realization of new experiments with appropriate dosages in order to verify if the biofortification really alters the amount of proteins, as well as sulfur amino acids and other parameters.

Given the widespread micronutrient deficiencies in vulnerable populations, crop biofortification has been proposed as a solution to increase nutrient concentrations. This study aimed to determine the effect of combining biofortification strategies on the agronomic characteristics and nutritional composition of potato. The effect of foliar fertilization (FF) with zinc (Zn) on five potato genotypes (G): four biofortified clones developed through conventional breeding with different Zn levels (high, medium, and low in Zn, and one high in Fe and Zn) and a commercial variety (‘Yungay’) were evaluated. At harvest, the number of tubers per plant, the weight of tubers per plant, and the average tuber weight were evaluated as yield components, and tuber samples were collected for micronutrient determination. For yield components, the analysis with linear mixed models showed no significant G × D interaction effects, but highly significant differences were observed among G. The Zn concentration in tubers showed a highly significant effect in the G × D interaction. The simple effects analysis showed that biofortified genotypes responded to FF with Zn by significantly increasing the tuber Zn concentrations by an average of 43% (range 28–61%), despite growing in alkaline soils. In contrast, the ‘Yungay’ variety showed a 6% increase. Clones biofortified through conventional genetic improvement responded better to agronomic FF with Zn compared to the non-biofortified commercial variety, demonstrating that both are synergistic strategies that can achieve a significant increase in Zn concentrations in tubers. The result of this study might be used to further biofortification efforts and decrease nutritional deficiencies.

To better understand the effects of agronomic practices on yield–nutrition relationships in wheat (Triticum aestivum L.) grains for Zn biofortification while improving yields simultaneously, effects of different soil fertilization and different drone-based foliar spraying treatments were investigated in calcareous soils. For soil fertilization, the incorporation of Zn or increasing the N/P ratio in compound fertilizers proved to be effective in enhancing grain Zn concentrations and yields. However, the overall effects of soil fertilization are limited, with a maximal yield increase of only 7.0% and a maximal increase of the grain Zn concentration from 19.4 to 27.0 mg/kg, which is far below the target biofortification value of 40–50 mg/kg. Unfortunately, there was a negative side effect, which decreased Fe and Mn concentrations and the Fe bioavailability. Notably, drone-based foliar Zn sprayings increased grain yields from the control 7.5 t/ha to 8.6 t/ha at ZnO treatment by 12.0% and 8.8 t/ha at ZnSO4·7H2O treatment by 17.3%. Meanwhile, grain Zn concentrations were increased from the control 33.5 mg/kg to 41.9 mg/kg at ZnO treatment by 25.1% and 43.6 mg/kg at ZnSO4·7H2O treatment by 30.1%. Treatments with ZnSO4·7H2O increased grain Zn concentrations and accumulation more so than ZnO, indicating the importance of chemical Zn forms in determining the effectiveness of foliar spraying. Moreover, foliar Zn sprayings simultaneously increased grain concentrations and accumulation of Fe, Mn and Cu, demonstrating multiple benefits. There were positive correlations between Zn and Fe, Mn or Cu, indicating synergistic interactions. Compared to micronutrients, concentrations of grain macronutrients (N, P, K, Ca and Mg) were less affected. Thus, a dual-benefit in both grain yields and micronutrient (particularly for Zn) nutrition could be effectively achieved through appropriate soil fertilization and foliar Zn spraying. These findings provide a better understanding of the yield–nutrition relationship among wheat grain yields, Zn and other nutrient elements for a better integrated manipulation to achieve a win–win situation in yield and nutrition.

IntroductionMicronutrient deficiencies, particularly iron (Fe) and zinc (Zn), are prevalent in a large part of the human population across the world, especially in children below 5 years of age and pregnant women in developing countries. Since wheat constitutes a significant proportion of the human diet, improving grain Fe and Zn content in wheat has become important in improving human health.ObjectiveThis study aimed to quantify the effect of foliar application of iron sulfate heptahydrate (FeSO4.7H2O) and zinc sulfate heptahydrate (ZnSO4.7H2O) and their combination on grain Fe and Zn concentrations, as well as grain protein content (GPC). The study also aimed to assess the utility of these applications in large field conditions.MethodsTo address this issue, field experiments were conducted using 10 wheat cultivars and applying a foliar spray of FeSO4.7H2O (0.25%) and ZnSO4.7H2O (0.50%) separately (@400 L of solution in water per hectare during each spray) and in combination at two different crop growth stages (flowering and milking) for three consecutive crop seasons (2017–2020). The study used a split-plot design with two replications to assess the impact of foliar application on GFeC, GZnC, and GPC. In addition, an experiment was also conducted to assess the effect of soil (basal) @ 25 kg/ha ZnSO4, foliar @ 2 kg/ha, ZnSO4.7H2O (0.50%), and the combination of basal + foliar application of ZnSO4 on the grain micronutrient content of wheat cultivar WB 02 under large field conditions.ResultsGFeC increased by 5.1, 6.1, and 5.9% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. GZnC increased by 5.2, 39.6, and 43.8% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. DBW 173 recorded the highest increase in GZnC at 56.9% with the combined foliar application of FeSO4 and ZnSO4, followed closely by HPBW 01 at 53.0% with the ZnSO4 foliar application, compared to the control. The GPC increased by 6.8, 4.9, and 3.3% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. Large-plot experiments also exhibited a significant positive effect of ZnSO4 not only on grain Zn (40.3%, p ≤ 0.001) and protein content (p ≤ 0.05) but also on grain yield (p ≤ 0.05) and hectoliter weight (p ≤ 0.01), indicating the suitability of the technology in large field conditions.ConclusionCultivars exhibited a slight increase in GFeC with solitary foliar applications of FeSO4, ZnSO4, and their combination. In contrast, a significant increase in GZnC was observed with the foliar application of ZnSO4 and the combined application of FeSO4 and ZnSO4. In terms of GPC, the most significant enhancement occurred with the foliar application of FeSO4, followed by ZnSO4 and their combination. Data demonstrated the significant effect of foliar application of ZnSO4 on enhancing GZnC by 39.6%. Large plot experiments also exhibited an increase of 40.3% in GZnC through the foliar application of ZnSO4, indicating the effectiveness of the technology to be adopted in the farmer’s field.

Abstract Background and aims Nano-zinc (Zn) fertilizer is an easily adaptable and environmentally safe alternative option that can effectively improve growth, yield and biofortification of common bean. Plant growth-promoting bacteria (PGPBs) could promote plant growth and nutrients availability in sustainable manner. Therefore, this study aimed to investigate the influence of foliar nano-Zn application in association with seed co-inoculations of PGPBs on growth, yield, biofortification and Zn use efficiencies in common bean cultivation. Two field experiments were performed with seven co-inoculations of PGPBs and three foliar nano-Zn doses applied 50% at R5 and 50% at R8 stages of common bean to determine plant height, shoot dry matter, grain yield, Zn concentration and uptake in shoot and grains, Zn partitioning index, daily Zn intake and Zn use efficiencies for agronomic biofortification. Results The combined foliar nano-Zn application and co-inoculation of R. tropici + B. subtilis enhance grain yield, leaf chlorophyll index, total protein content, grain Zn concentration and uptake, daily Zn intake, Zn use efficiency, applied Zn recovery and Zn utilization efficiency in common beans in 2019 and 2020 cropping seasons. Foliar nano-Zn application at a dose of 1.5 kg ha−1 increased plant height, shoot dry matter, shoot Zn uptake, Zn partitioning and agro-physiological efficiency under co-inoculation with R. tropici + B. subtilis in both cropping years. Conclusions The treatments with foliar nano-Zn application at a dose of 1.5 ha−1 and co-inoculation with R. tropici + B. subtilis improved performance, chlorophyll index, protein content, grain yield, and Zn efficiencies that can lead to better biofortification of common bean in tropical savannah. Therefore, it is recommended that applying nano-Zn via foliar along with co-inoculation of PGPBs could be the better option for productivity and biofortification of common bean. Graphical Abstract

Zinc (Zn) deficiency represents a significant global concern, affecting both plant and human health, particularly in regions with Zn-depleted soils. Agronomic biofortification strategies, such as the application of Zn fertilizers, offer a cost-effective approach to increase Zn levels in crops. This study aimed to assess the efficacy of soil and foliar Zn biofortification, applied as an aqueous solution of 0.5% zinc sulphate (ZnSO4·7H2O), on triticale (x Triticosecale) grown under Mediterranean conditions. The study was conducted over two growing seasons (2017/18 and 2018/19) in southern Spain, evaluating the effects on biomass yield; forage quality, including crude protein, Van Soest detergent fiber, organic matter digestibility, and relative forage value; and nutrient accumulation. Soil treatment consisted in the application of 50 kg of ZnSO4·7H2O ha−1 solely at the beginning of the first campaign to assess the residual effect on the second year. In contrast, the foliar treatment consisted of two applications of 4 kg of ZnSO4·7H2O ha−1 per campaign, one at the beginning of tillering and the other at the appearance of the first node. The foliar application increased the Zn content of the forage to adequate levels, while the soil application resulted in a 33% increase in biomass production, which is particularly beneficial for farmers. Overall quality was favored by the combined soil + foliar application, and no adverse antagonistic effects on other nutrients were detected. Instead, a synergistic interaction between Se and Zn was observed, which improved the efficacy of this important micronutrient for livestock and human wellbeing.

Nanotechnology has been increasingly used in plant sciences, with engineered nanoparticles showing promising results as fertilizers or pesticides. The present study compared the effects in the foliar application of Se nanoparticles (SeNPs) or sodium selenite-Se(IV) on rice seedlings. The degree of plant growth, photosynthetic pigment content, and concentrations of Se, Na, Mg, K, Ca, Mn, Co, Cu, Zn, As, Cd, and Pb were evaluated. The results showed that the application of SeNPs at high concentrations (5 mg L−1), as well as the application of Se(IV), inhibited plant growth and increased the root concentrations of As and Pb. The application of SeNPs at 0.5 mg L−1 significantly increased Se accumulation in the aerial part from 0.161 ± 0.028 mg kg−1 to 0.836 ± 0.097 mg kg−1 without influencing physiological, chemical, or biochemical parameters. When applied to leaves, SeNPs tended to remain in the aerial part, while the application of Se(IV) caused a higher Se translocation from the shoots to the roots. This study provides useful information concerning the uptake, accumulation, and translocation of different Se formulations in rice seedlings and their effect on plant ionomic profiles, thus showing that the foliar application of SeNPs at low concentrations can be an effective and safe alternative for rice biofortification.

The biofortification of edible crops with selenium (Se) is a common and effective strategy to address inadequate Se intake, which is suffered by millions of people worldwide. However, there is little information regarding the effects of this practice on crops belonging to the important Brassica family. To evaluate the efficacy of foliar Se application on broccoli, four treatments with varying Se concentrations were tested: 0%, 0.05%, 0.10%, and 0.15% (w/v), applied as sodium selenate during the early flowering stage. Although no overall effects on growth and biomass parameters were observed, the results indicate that the lowest Se dose (0.05-Se) was sufficient to notably increase Se concentration in the florets, even after boiling. Based on the increase to 14.2 mg Se kg−1 of dry matter in this broccoli fraction, it was estimated that consuming a 100-gram portion of boiled florets biofortified with 0.05% Se would provide approximately 140 µg of Se, which could be sufficient to potentially improve human selenium status, as previously documented. Moreover, the results obtained underscore how the application of this small dose was also adequate to reduce phytate concentration in the florets and to increase antioxidant and polyphenol concentrations, thereby improving the concentration and bioavailability of other essential nutrients, including Ca, Mg, Fe, and Zn, along with improving its quality as an antioxidant food.

Agronomic biofortification of wheat grain with zinc can improve the condition of about one billion people suffering from zinc (Zn) deficiency. However, with the challenge of cultivating high-yielding wheat varieties in Zn-deficient soils and the global need to produce higher-quality food that nourishes the growing population, innovation in the strategies to deliver Zn directly to plants will come into play. Consequently, existing foliar formulations will need further refinement to maintain the high agronomic productivity required in competitive global grain markets while meeting the dietary Zn intake levels recommended for humans. A new generation of foliar fertilisers that increase the amount of Zn assimilated in wheat plants and the translocation efficiency of Zn from leaves to grains can be a promising solution. Research on the efficacy of adjuvants and emerging nano-transporters relative to conventional Zn forms applied as foliar fertilisers to wheat has expanded rapidly in recent years. This review scopes the range of evidence available in the literature regarding the biofortification of bread wheat (Triticum aestivum L.) resulting from foliar applications of conventional Zn forms, Zn nanoparticles and novel Zn-foliar formulations. We examine the foliar application strategies and the attained final concentration of grain Zn. We propose a conceptual model for the response of grain Zn biofortification of wheat to foliar Zn application rates. This review discusses some physiological aspects of transportation of foliarly applied Zn that need further investigation. Finally, we explore the prospects of engineering foliar nano-formulations that could effectively overcome the physicochemical barrier to delivering Zn to wheat grains. [ABSTRACT FROM AUTHOR]

Agronomic biofortification, encompassing the use of mineral and organic nutrient resources which improve micronutrient concentrations in staple crops is a potential strategy to promote the production of and access to micronutrient-dense foods at the farm level. However, the heterogeneity of smallholder farming landscapes presents challenges on implementing agronomic biofortification. Here, we test the effects of zinc (Zn)- and selenium (Se)-containing fertilizer on micronutrient concentrations of wheat (Triticum aestivum L.) and teff (Eragrostis tef (Zucc.) Trotter) grown under different landscape positions and with different micronutrient fertilizer application methods in the western Amhara region of Ethiopia. Field experiments were established in three landscape positions at three sites, with five treatments falling into three broad categories: (1) nitrogen (N) fertilizer rate; (2) micronutrient fertilizer application method; (3) sole or co-application of Zn and Se fertilizer. Treatments were replicated across five farms per landscape position and over two cropping seasons (2018 and 2019). Grain Zn concentration ranged from 26.6 to 36.4 mg kg−1 in wheat and 28.5–31.2 mg kg−1 in teff. Grain Se concentration ranged from 0.02 to 0.59 mg kg−1 in wheat while larger concentrations of between 1.01 and 1.55 mg kg−1 were attained in teff. Larger concentrations of Zn and Se were consistently attained when a foliar fertilizer was applied. Application of ⅓ nitrogen (N) yielded significantly larger grain Se concentration in wheat compared to a recommended N application rate. A moderate landscape effect on grain Zn concentration was observed in wheat but not in teff. In contrast, strong evidence of a landscape effect was observed for wheat and teff grain Se concentration. There was no evidence for any interaction of the treatment contrasts with landscape position except in teff, where an interaction effect between landscape position and Se application was observed. Our findings indicate an effect of Zn, Se, N, landscape position, and its interaction effect with Se on grain micronutrient concentrations. Agronomic biofortification of wheat and teff with micronutrient fertilizers is influenced by landscape position, the micronutrient fertilizer application method and N fertilizer management. The complexity of smallholder environmental settings and different farmer socio-economic opportunities calls for the optimization of nutritional agronomy landscape trials. Targeted application of micronutrient fertilizers across a landscape gradient is therefore required in ongoing agronomic biofortification interventions, in addition to the micronutrient fertilizer application method and the N fertilizer management strategy. [ABSTRACT FROM AUTHOR]

The low availability of micronutrients in the soil leads to a deficit of these micronutrients in crops, causing malnutrition in the population. Approximately 3,000 million people in the world have health problems caused by inadequate Zn intake. Agronomic biofortification is a way to produce crops rich in micronutrients and mitigate malnutrition problems. Nano biofortification with zinc oxide nanoparticles (NPs-ZnO) is a good strategy to mitigate and increase the nutritional content of the edible part of the plant. The aim was to determine the effect of foliar spraying with NPs-ZnO on yield and biosynthesis of enzymatic and nonenzymatic antioxidant compounds and their bioaccumulation. In this study, the effect of foliar fertilization with NPs-ZnO: 0, 25, 50, 75, and 100 mg L-1, on yield, the content of bioactive compounds and their bioaccumulation in grapevine berries was evaluated. The distribution of the treatments was under a completely randomized design, each treatment consisted of 10 plants, each representing one experimental unit. The treatments were applied by foliar sprays at fruit formation, in veraison and 15 days before harvest. Foliar spraying with NPs-ZnO positively modifies yield, the content of bioactive compounds, and their bioaccumulation. Doses of 50-75 mg L-1 of NPs-ZnO increased crop yield, and oenological parameters. In addition, all doses evaluated modified enzymatic and non-enzymatic antioxidants, and improving Zn concentration in grapevine berries. Foliar spraying of NPs-ZnO is an alternative to improve grape quality and yield, in addition to enriching its nutritional and antioxidant content. [ABSTRACT FROM AUTHOR]

Aims: Fertilisating crops with zinc (Zn) is considered important to enhance agricultural productivity and combat human Zn deficiencies in sub-Saharan Africa. However, it is unclear on which soils Zn fertilisation can lead to higher yields and increased grain Zn concentrations. This study aimed to find soil properties that predict where soil Zn is limiting maize yields and grain Zn concentrations, and where these respond positively to Zn fertilisation. Methods: Zinc omission trials were set up at multiple farm locations in Kenya (n = 5), Zambia (n = 4) and Zimbabwe (n = 10). Grain yields and tissue Zn concentrations were analysed from plots with a full fertiliser treatment as compared to plots where Zn was omitted. Results: A positive maize yield response to soil Zn fertilisation was found at only two out of nineteen locations, despite soil Zn levels being below suggested critical concentrations at most locations. Soil properties nor plant concentrations were able to explain maize yield response to Zn fertilisation. However, positive responses in Zn uptake and grain Zn concentrations to Zn fertilisation were found at the majority of sites, especially in soils with low pH and organic carbon contents. Labile soil Zn measurements related more with Zn uptake (R2 = 0.35) and grain Zn concentrations (R2 = 0.26) than actual available Zn measurements. Conclusions: We conclude that soil Zn fertilisation did not increase maize yields, but can increase maize grain Zn concentrations, especially in soils with low pH and organic carbon content. Predicting a yield response to Zn fertilisation based on soil properties remains a challenge. [ABSTRACT FROM AUTHOR]

Salinity is among major environmental constraints in arid and semi-arid regions of the world that is deteriorating soil fertility and reducing uptake of micronutrients especially Fe and Zn. The crop plants grown in calcareous and high pH soils are inherently low in these mineral nutrients. Wheat (Triticum aestivum L.) is the principal diet for almost one third of world's population. The information regarding the fortification of wheat with Fe and Zn under saline conditions is limited. The soil and foliar application of Fe and Zn may be helpful for improving the nutritional quality of wheat produced from salt-affected land. The aim of present study was to assess the responses of selected wheat cultivars (Faisalabad-2008 and Galaxy-2013) to soil and foliar application of Fe and Zn under saline conditions. Foliar and soil application of Fe and Zn was done individually as well as in combination. The experimental units were replicated thrice in Completely Randomized Design (CRD). The data of various wheat growth, ionic and biochemical parameters including grain yield, total chlorophyll contents, root and shoot length, root and shoot dry weights, Zn, Fe, K, and Na, SOD and CAT enzyme activity were recorded using standard procedures. It was clearly depicted by the results that the presence of salt stress in the growth medium significantly (p ≤ 0.05) deteriorated plant growth and yield. Also, the results showed that Zn and Fe application significantly (p ≤ 0.05) increased wheat plant growth under salt stress. The foliar application proved to be more efficient than soil application. However, the plants that contained combined application (soil and foliar) of Fe and Zn gave maximum yield as well as higher accumulation of Fe, Zn, and K in shoot and grains. It was, therefore, concluded that the combined soil and foliar application of Fe and Zn is an effective strategy to ameliorate micronutrients (Fe and Zn) deficiency in crops grown under salt-affected soil conditions. [ABSTRACT FROM AUTHOR]

The effect of soil selenate application to two different soils (Phaeozem and Cambisol) on biomass yield and selenium (Se) uptake by spring wheat (Triticum aestivum L.) was investigated in a pot experiment. Additionally, organic amendment (fugate, i.e. liquid by-product from the biogas plant) was applied to assess (i) the effect of organic matter on the bioavailability of Se and (ii) the fugate (containing 2.3 mg/kg of Se) as a potential source of Se for plants. Selenium was applied at two levels: 6.4 µg/kg (Se1) and 32 µg/kg (Se2) of soil. The efficiency of biofortification and the distribution of selenium within individual plant compartments were assessed in this case. The highest Se contents in the grain were achieved in the treatments receiving NPK fertiliser together with selenate, 455 µg/kg (Se1) and 2 721 µg/kg (Se2) when wheat was planted in Phaeozem. Fugate in co-application with selenate significantly reduced Se content in wheat plants as compared to treatments enriched solely with selenate. The lower Se contents in the wheat plants growing in Phaeozem were due to the biodilution effect, whereas in Cambisol, the decrease in wheat Se uptake was not clearly driven by a particular factor.

AimZinc deficiencies are widespread in many soils, limiting crop growth and contributing to Zn deficiencies in human diets. This study aimed at understanding soil factors influencing grain Zn concentrations and uptake of crops grown in different landscape positions in West Amhara, Ethiopia.MethodsOn-farm experiments were conducted in three landscape positions, with five farmers’ fields as replicates in each landscape position, and at three sites. Available Zn from the soil (Mehlich 3, M3, Zn) and applied fertilizer (NET_FERT Zn, estimated based on adsorption/desorption characteristics and applied Zn) were related to the actual grain Zn concentration and uptake of teff, wheat, and maize. Zinc fertilizer treatments tested were Zn applied at planting (basal), basal plus side dressing and a control with no Zn applied.ResultsZn treatments had a significant effect on grain Zn concentration (increase by up to 10%) but the effect on grain yield was variable. Differences in crop Zn concentrations along the landscape positions were observed but not at all sites and crops. Trial results showed that soils with higher soil pH and Soil Organic Carbon (SOC) (typical of footslope landscape positions) tended to adsorb more applied Zn (reduce NET_FERT Zn) than soils with lower soil pH and SOC (typical of upslope landscape positions). Zn availability indicators (M3, NET_FERT Zn, clay%) explained 14-52% of the observed variation in grain Zn concentrations, whereas macronutrient indicators (Total N, exchangeable K) together with M3 Zn were better in predicting grain Zn uptake (16 to 32% explained variability). Maize had the lowest grain Zn concentrations but the highest grain Zn uptake due to high yields.ConclusionWe found that the sum of indigenous and fertilizer Zn significantly affects grain Zn loadings of cereals and that the associated soil parameters differ between and within landscape positions. Therefore, knowledge of soil properties and crop characteristics helps to understand where agronomic biofortification can be effective.

Background and aims: Nano-zinc (Zn) fertilizer is an easily adaptable and environmentally safe alternative option that can effectively improve growth, yield and biofortification of common bean. Plant growth-promoting bacteria (PGPBs) could promote plant growth and nutrients availability in sustainable manner. Therefore, this study aimed to investigate the influence of foliar nano-Zn application in association with seed co-inoculations of PGPBs on growth, yield, biofortification and Zn use efficiencies in common bean cultivation. Two field experiments were performed with seven co-inoculations of PGPBs and three foliar nano-Zn doses applied 50% at R5 and 50% at R8 stages of common bean to determine plant height, shoot dry matter, grain yield, Zn concentration and uptake in shoot and grains, Zn partitioning index, daily Zn intake and Zn use efficiencies for agronomic biofortification. Results: The combined foliar nano-Zn application and co-inoculation of R. tropici + B. subtilis enhance grain yield, leaf chlorophyll index, total protein content, grain Zn concentration and uptake, daily Zn intake, Zn use efficiency, applied Zn recovery and Zn utilization efficiency in common beans in 2019 and 2020 cropping seasons. Foliar nano-Zn application at a dose of 1.5 kg ha−1 increased plant height, shoot dry matter, shoot Zn uptake, Zn partitioning and agro-physiological efficiency under co-inoculation with R. tropici + B. subtilis in both cropping years. Conclusions: The treatments with foliar nano-Zn application at a dose of 1.5 ha−1 and co-inoculation with R. tropici + B. subtilis improved performance, chlorophyll index, protein content, grain yield, and Zn efficiencies that can lead to better biofortification of common bean in tropical savannah. Therefore, it is recommended that applying nano-Zn via foliar along with co-inoculation of PGPBs could be the better option for productivity and biofortification of common bean. Highlights: Foliar nano-zinc (Zn) fertilization can improve agronomic biofortifcation and producitvity of common beans. Plant growth-promoting bacteria (PGPBs) can sustainably increase nutrient use efficiency and zinc content in edible tissues. The combined application of nano-Zn and PGPBs can potentially alleviate food and nutritional security crises. The sustianbale mechanisms of co-application of nano-Zn and PGPBs need further investigation. [ABSTRACT FROM AUTHOR]

Micronutrient deficiencies (MNDs), also known as hidden hunger, affect more than a quarter of the global population. Agronomic biofortification helps to increase the concentration of a target mineral in food crops and improve human mineral dietary intake. It is a means of providing nutrient-dense foods to a larger population, especially among rural resource-poor settings, providing that they have access to mineral fertilizers. However, the feasibility of agronomic biofortification in combating hidden hunger depends on several factors in addition to fertilizer access, including crop type, genotype, climate, soils, and soil mineral interactions. Consideration of its effectiveness in increasing human mineral intake to the daily requirements and the improvement of human health and the cost-effectiveness of the program is also important. In this paper, we review the available literature regarding the potential effectiveness and challenges of agronomic biofortification to improve crop micronutrient concentrations and reduce hidden hunger. [ABSTRACT FROM AUTHOR]

Human micronutrient deficiencies are a major issue around the globe and mostly affect those whose diets are primarily made up of plant-based foods and do not contain sufficient quantities of important vitamins and minerals. Micronutrient deficiency in plants is associated with their declining level in soils, limited bioavailability, and the presence of abiotic stressors that interfere with the healthy growth and development of plants. Field experiments were conducted in lentil sown at two different times to study the effects of foliar-applied Zn, B, and Fe on grain yield and grain concentrations of micronutrients. Field experiments were undertaken in clay loam soil (Aeric Haplaquept) in eastern India during the winter seasons of 2018–2019 and 2019–2020, to cultivate rainfed lentil with residual moisture. Lentil crop was sown on two different sowing dates (in November and December) to expose one of the crops to higher temperature and moisture stress. Foliar spray of zinc (Zn 0.5%), boron (B 0.2%), and iron (Fe 0.5%) was applied either individually or in combination at the preflowering and pod development stage. These three micronutrients are essential humans. They have also been reported to alleviate plant stress. Our study reported that foliar spray of micronutrients twice during lentil growth stages can fortify seeds with required nutrients and also alleviate stress in late-sown conditions. [ABSTRACT FROM AUTHOR]

Agronomic biofortification of wheat grain with zinc can improve the condition of about one billion people suffering from zinc (Zn) deficiency. However, with the challenge of cultivating high-yielding wheat varieties in Zn-deficient soils and the global need to produce higher-quality food that nourishes the growing population, innovation in the strategies to deliver Zn directly to plants will come into play. Consequently, existing foliar formulations will need further refinement to maintain the high agronomic productivity required in competitive global grain markets while meeting the dietary Zn intake levels recommended for humans. A new generation of foliar fertilisers that increase the amount of Zn assimilated in wheat plants and the translocation efficiency of Zn from leaves to grains can be a promising solution. Research on the efficacy of adjuvants and emerging nano-transporters relative to conventional Zn forms applied as foliar fertilisers to wheat has expanded rapidly in recent years. This review scopes the range of evidence available in the literature regarding the biofortification of bread wheat (Triticum aestivum L.) resulting from foliar applications of conventional Zn forms, Zn nanoparticles and novel Zn-foliar formulations. We examine the foliar application strategies and the attained final concentration of grain Zn. We propose a conceptual model for the response of grain Zn biofortification of wheat to foliar Zn application rates. This review discusses some physiological aspects of transportation of foliarly applied Zn that need further investigation. Finally, we explore the prospects of engineering foliar nano-formulations that could effectively overcome the physicochemical barrier to delivering Zn to wheat grains.

The global threat of food security and food production for ever-increasing population are the key challenges nowadays. Enhanced agriculture production and a rise in the quality of crops are needed. Sustainable and eco-friendly agriculture approaches are required to improve crop yield and nutritional value which is decreased because of an increase in population rate, changing climate and inflation in a hidden hunger. Crop biofortification could overcome these challenges. Biofortification will indirectly target low-income households who cannot afford a more diverse diet by capitalizing on the consistent daily intake of food staples. Biofortified crops can be developed by conventional plant breeding, agronomic strategies and genetic engineering but these have not always been successful. In recent years, use of naturally occurring microorganisms in the soil, i.e. plant growth promoting microbes (PGPM) most especially bacteria and mycorrhizal fungi has been recommended as a promising approach for the biofortification of important crops. Micronutrient contents in different plant tissues such as roots, leaves and fruits can be enhanced by inoculation of soil and crops with rhizospheric and endophytic microbes. PGPM fortifies crops by a different mechanism such as siderophore production, zinc solubilization, nitrogen fixation, and phosphate solubilization. Microbial biofortification is a novel strategy because it not only the increases concentration of micronutrients in edible food crops but also improves yield on less fertile soil. In this review we are emphasizing the biofortification of crops by microbes as a sustainable and cost-effective alternation for improving Fe, Zn and Se content of crops. [ABSTRACT FROM AUTHOR]

This study investigated the impacts of spraying iodine (I) as potassium iodide (KI) and K-iodate (KIO3) with/without calcium chloride (CaCl2) on apple (Malus domestica Borth.) enrichment with I as well as on fruit quality. 'Idared' apple trees were sprayed with I: (i) in the summer, five times at a rate of 0.1 kg ha−1 in each treatment with or without CaCl2 and (ii) preharvest (2 weeks before harvest) at a rate of 0.5 kg ha−1. Iodine concentrations in apples sprayed with this nutrient in the summer varied from 41 to 70 µg 100 g−1 FW. The preharvest I sprays increased apple I concentrations up to 63–69 µg 100 g−1 FW. Only the addition of CaCl2 to the spray solution containing KIO3 enhanced fruit I concentration. The sprays of I with CaCl2 increased apple Ca concentration as well as flesh firmness and contents of organic acids in fruit after storage. The percentage of I losses did not differ between combinations, averaging 11.3%. It is concluded that the summer sprays of KI or KIO3 with CaCl2 should be recommended to biofortify apples with I and improve their Ca-related storability. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the influence of genotypic differences on responses to zinc and iron agronomic biofortification among yields of finger millet. A field experiment was conducted over two seasons in farmers' fields in Ethiopia (2019, 2020). The experimental design had 15 treatment combinations comprising three finger millet genotypes and the applications of different combinations of zinc and iron mineral fertilizers. Five soil-applied fertilizer treatments (20 kg h−1 FeSO4 + 25 kg h−1 ZnSO4 + NPKS, 25 kg ha−1 ZnSO4 + NPKS, 20 kg ha−1 FeSO4 + NPKS, NPKS, and 30% NPKS) at two locations (Gojjam and Arsi Negelle, Ethiopia) and using two slope positions (foot and hill) were replicated four times in a randomized complete block design. Grain yield and biomass were evaluated on a plot basis. Plant height, total and productive tiller number, finger length of the longest spike and number of fingers per main ear were measured at the maturity stage. The combined soil application of FeSO47H2O and ZnSO47H2O increased the yield of the Meba genotype by 51.6%. Additionally, ZnSO47H2O fertilizer application increased the yield of the Urji genotype by 27.6%. A yield enhancement of about 18.3% of the Diga-01 genotype was achieved due to the FeSO47H2O fertilizers' application. The findings of the present study suggest that the influence of Zn and Fe agronomic biofortification on the yield of finger millet could be affected by genotype differences and environmental conditions. [ABSTRACT FROM AUTHOR]