Zn Concentration In Grain Research Articles

Effects of foliar spraying different sizes of zinc fertilizer on the growth and cadmium accumulation in rice.

Nanotechnology has been widely applied in agricultural science. During the process of reducing metal toxicity and accumulation in rice, nanomaterials exhibit size effects. However, there is limited knowledge regarding these size effects. We aim to explore the impact of fertilizer with various sizes of ZnO nanoparticles (ZnO-NPs) on rice growth and cadmium (Cd) accumulation and to elucidate the potential mechanism of Cd reduction in rice. Foliar applications of different concentrations (0.5 and 2 mmol L-1) and different sizes (30 and 300 nm ZnO-NPs) of zinc (Zn) fertilizer (Zn(NO3)2) were performed to investigate the effects on rice growth, Cd accumulation and subcellular distribution, and the expression of Zn-Cd transport genes. The results suggested that all the foliar sprayings can significantly reduce the Cd concentrations in rice grains by 41-61% with the highest reduction in the application of ZnO-NPs with large size and low concentration. This is related to the enhancement of Cd fixation in leaf cell walls and downregulation of Cd transport genes (OsZIP7, OsHMA2, OsHMA3) in stem nodes. Foliar ZnO-NPs applications can increase the Zn concentration in grains by 9-21%. Foliar applications of Zn(NO3)2 and small-sized ZnO-NPs promoted plant growth and rice yield, while the application of large-sized ZnO-NPs significantly reduced rice growth and yield. The study suggests that the rice yield and Cd reduction are dependent on the size and concentration of foliar spraying and the use of large-sized ZnO-NPs is the most effective strategy when considering both yield and Cd reduction comprehensively. © 2024 Society of Chemical Industry.

Agronomic Biofortification Increases Concentrations of Zinc and Storage Proteins in Cowpea Grains

Zinc (Zn) is crucial for both plant metabolism and human nutrition, with its deficiency being a global health concern. Strategies to increase its availability in food, such as agronomic biofortification, have gained prominence. This study evaluated the impact of foliar spraying of Zn [at full bloom stage: 0 (control) and 600 g ha−1, as ZnSO4⋅7H2O] on the nutritional quality of cowpea (Vigna unguiculata L. Walp.) grains. Field experiments involving 20 cowpea genotypes were carried out over two seasons in a Typic Quartzipsamment under a no-tillage system. The photosynthetic responses of cowpea plants and the concentrations of Zn, amino acids, sucrose, total sugars, and storage proteins (glutelin, albumin, prolamin, and globulin) in grains were analyzed. All genotypes showed enrichment of Zn in grains in response to ZnSO4⋅7H2O application compared to untreated plants. Foliar spraying of ZnSO4⋅7H2O during initial grain filling was ideal for increasing Zn concentration in grains and improving plant physiological processes. Additionally, Zn fertilization led to higher concentrations of storage and total amino acids and proteins in the grains, supporting the rational application of Zn in cowpea production to improve the nutritional quality of grains and increase plant productivity.

Unravelling the impact of soil types on zinc, iron, and selenium concentrations in grains and straw of wheat/Amblyopyrum muticum and wheat/Triticum urartu doubled haploid lines

The concentration of mineral nutrients in plants is associated with bioavailabilities of soil mineral nutrients, which are regulated by various soil physio-chemical properties. A pot experiment was conducted to investigate the effects of soil type on grain and straw zinc (Zn), iron (Fe) and selenium (Se) concentrations of wheat/Amblyopyrum muticum and wheat/Triticum urartu doubled haploid lines. A set of 42 treatments in a factorial combination with 21 genotypes and two soil types collected from Ngabu and Chitedze Research Stations in Malawi was laid in a randomised complete block design (RCBD) in three replicates. Pre-experiment soil Zn and Fe were extracted using DTPA extraction method followed by analysis with inductively coupled plasma-mass spectrometry (ICP-MS). Aqua-regia hotplate acid digestion was used to extract soil Se and analysis was done using ICPM-MS. Grain and straw samples were digested using nitric acid digestion (HNO3) and analysed using ICP-MS. Soil analysis results showed that the two soils had the same textural class (Sandy clay loam), but different mineral concentrations, pH levels and percentage organic matter. Analysis of variance revealed a ~two-fold higher Zn concentration in grains grown in low pH, high Zn soils (Chitedze soils) compared to grains grown in high pH, low Zn soils (Ngabu soils). Variation in grain Zn concentration was associated with the genotypes (p = 0002), soil type (p = <0.0001), and their interaction (p = 0.035). Grain Fe was 1.3-fold higher in low pH than in high pH soils, and it was influenced by genotypes (p = < 0.0001) and soil type (p = <0.0001). Grain Se was highly associated with soil type (p = <0.0001), and it was 30-fold higher in high pH than in low pH soils. Straw Zn was generally higher in plants grown in Chitedze soils than Ngabu soils, whilst straw Se was higher in plants grown in Ngabu soils than Chitedze soils. The findings demonstrate the significance of soil physio-chemical properties for mineral accumulation and distribution to plant parts, thus informing future breeding programs on important considerations on crop genetic biofortification with the three mineral elements.

Interactive Suitability of Rice Stubble Biochar and Arbuscular Mycorrhizal Fungi for Improving Wastewater-Polluted Soil Health and Reducing Heavy Metals in Peas

Arable soils irrigated with wastewater (SIWs) cause ecological and human health issues due to the presence of heavy metals (HMs). Burning rice stubble (RS) poses severe environmental and human health hazards. Converting RS into rice stubble compost (RSC) and rice stubble biochar (RSB) can overcome these issues. Here, we considered the role of RS, RSC, and RSB as individual soil amendments and combined each of them with arbuscular mycorrhiza fungi (AMF) to observe their effectiveness for HM immobilization in SIW, their uptake in pea plants, and improvements in the physicochemical properties of soil. The results revealed that adding RSB and AMF reduced the bioavailable concentrations of Pb, Cd, Ni, Cu, Co, and Zn in SIW by 35%, 50%, 43%, 43%, 52%, and 22%, respectively. Moreover, RSB+AMF treatment also reduced Pb, Cd, Ni, Cu, Co, and Zn concentrations in grain by 93%, 76%, 83%, 72%, 71%, and 57%, respectively, compared to the control. Improvements in shoot dry weight (DW) (66%), root DW (48%), and grain yield (56%) per pot were also the highest with RSB+AMF. RSB+AMF treatment enhanced soil health and other soil attributes by improving the activity of urease, catalase, peroxidase, phosphatase, β-glucosidase, and fluorescein diacetate by 78%, 156%, 62%, 123%, 235%, and 96%, respectively. Interestingly, RSB+AMF also led to the strongest AMF–plant symbiosis, as assessed by improved AMF root colonization (162%), mycorrhizal intensity (100%), mycorrhizal frequency (104%), and arbuscular abundance (143%). To conclude, converting RS into RSB can control air pollution caused by RS burning. Moreover, adding RSB with AMF to SIW can reduce HM uptake in plants, improve soil health, and thus minimize ecological and human health issues.

Soil and foliar zinc application techniques influence the productivity, zinc concentration, and protein content in the grains of bread wheat varieties

Micronutrient zinc (Zn) is crucial for both humans and plants. To improve the micronutrient concentration in the grains of food crops, biofortification has already been established as one of the best approaches across the globe. The current study was carried out to assess Zn enrichment in a few common wheat varieties using different Zn delivery techniques. The following treatments were applied: T<sub>1</sub>: control (without Zn), T<sub>2</sub>: Soil application of 4 kg Zn ha-1 at final land preparation, T<sub>3</sub>: Foliar application of a 0.5% Zn solution (ZnSO<sub>4</sub> x7H<sub>2</sub>O) at both tillering and booting stages, and T<sub>4</sub>: soil application of 2 kg Zn ha-1 at final land preparation + foliar application of a 0.2% Zn solution (ZnSO<sub>4</sub> x7H<sub>2</sub>O) at both tillering and booting stages. All treatments were arranged in a split-plot design and repeated three times The findings of the study revealed that the various Zn application techniques had an impact on the Zn concentration in grains significantly, ranging from 23.9 to 32.2 µg g-1 across the varieties, with an average of 28.2 µg g-1 in the control. Among these various application techniques, the soil + foliar application induced the highest response of the Zn concentration in the grains ranging from 33.7 to 37.60 µg g-1. The average protein content (%) in the grains of all wheat varieties varied by 1.21, 1.47, and 1.51%, respectively, as a result of the use of the different Zn application methods. Considering the Zn-use efficiency (%), the most Zn-efficient wheat variety was BARI Gom 28, followed by BARI Gom 26, Binagom-1, BARI Gom 25, and BARI Gom 29. In the case of grain yield, wheat variety BARI Gom 26 (4.15 t ha-1) performed the best in the soil + foliar Zn application. The soil + foliar application method outperformed the other application techniques regarding the Zn concentration, yield, and protein content in the grain.

Soil and foliar application of Zn enhances its biofortification, bioavailability and productivity in both biofortified and non-biofortified wheat varieties

In a two-year field study, the agronomic approaches to enhance zinc content and bioavailability in grains of both biofortified and non-biofortified wheat varieties were investigated. During both years of the study, the biofortified variety PBW 1 Zn demonstrated significantly higher grain yield (5.8 and 5.7 t ha–1), which were statistically comparable to the non-biofortified variety HD 2967 (5.7 and 5.5 t ha–1). Similarly, upon Zn fertilization, PBW 1 Zn exhibited a 25% higher Zn concentrations in grains (50 mg kg–1), along with a greater total Zn accumulation (504 g ha–1) and higher Zn mobilization efficiency index (ZnMEI) of 2.0. Additionally, the PBW 1 Zn demonstrated elevated grain nitrogen content (2.2%) and total nitrogen accumulation (189 kg ha–1). Conversely, it displayed a reduced phosphorus content (0.30%), phytic acid content (9 mg g–1), and PA/Zn molar ratio (18) in its grains. Among the Zn fertilization strategies, soil + foliar Zn resulted in higher grain and straw yields by 14% and 7%, respectively, followed by foliar application, and soil application. Further, soil + foliar application of Zn increased the Zn concentration in grain and straw by 47% and 37%, respectively, and grain N content by 19%. Simultaneously, this method decreased the phytic acid content and PA/Zn molar ratio by 20%, and 47%, respectively. Conclusively, the soil + foliar Zn application augmented the qualities of the genetically biofortified variety PBW 1 Zn, leading to higher yields, nutritional attributes, and bioavailability of Zn.

Genetic analysis of grain biochemical parameters and yield in pearl millet [Pennisetum glaucum (L.) R. Br.

Pearl millet is a potential crop to combat micronutrient deficiency through genetic biofortification of micronutrients in addition to protein, carbohydrates and oil. There is very limited information available regarding gene action for micronutrient content and other biochemical properties like carbohydrate, protein, oil and tannin content in pearl millet. ANOVA revealed significant differences between families and generations for all biochemical traits except protein content. Generation mean analysis through a six-parameter model exposed a prevalence of all kinds of genetic effects that govern Fe and Zn concentrations in grain in crosses 15611R × 42182-HP and 15695R × 15787R, respectively. Furthermore, fixable and heritable genetic variance like additive and additive × additive were found substantial for Fe content in most of the families. Zinc, tannin content and grain yield per plant were governed by heritable but non-fixable intra-allelic interactions in most of the crosses. Likewise, carbohydrate content showed significant additive gene action in crosses except cross 6055B × 15611R. The cross 6055B × 15611R provided the opportunity for developing a biofortified variety with a low tannin level as it exhibited negative heterosis for tannin content and positive heterosis for iron, zinc and carbohydrates content.

Heterosis and combining ability of iron, zinc and their bioavailability in maize inbred lines under low nitrogen and optimal environments

Iron (Fe) and zinc (Zn) nutrient enrichment of staple crops through biofortification can contribute to alleviating micronutrient deficiency in sub-Saharan Africa. A line × tester mating design was used to determine the general combining ability (GCA), specific combining ability (SCA) and heterosis for grain yield, iron, Zn and phytic concentration of six lines crossed with three testers. Lines and testers were selected for high, intermediate and low mineral content. The F1 hybrids and parental lines were evaluated under low nitrogen (N) and optimum conditions across four environments over two seasons. Under low N conditions, Fe and Zn concentration in grain, and grain yield of genotypes were reduced by 9%, 9%, and 59%, respectively. However, phytic acid concentration in grain was increased by 10% under low N conditions. Both additive and non-additive gene effects were important in controlling Fe, Zn and phytic acid concentration in grain and grain yield of maize under both N conditions. The preponderance of GCA effects indicates the importance of additive gene effects in the inheritance of grain yield. Line GCA effects were more sensitive to N conditions across the environments than the tester GCA. High and significant positive SCA effects for grain yield, Fe and Zn content under low N conditions, would be a good indicator of possible heterosis in these traits. Hybrid CBY101 LM-1600 × CBY358 LM-1857 had high and significant positive SCA for grain yield under low N conditions and is a promising candidate for production in low N environments. CBY358 LM-1857 (tester) and CBY102 LM-1601 (line) are a good general combiners for Fe, Zn and GY can be used as parents in future maize hybrid breeding programs to develop high-yielding maize genotypes with high Fe and Zn content.

Zinc concentration and bioavailability of Chinese steamed bread prepared from foliar zinc-biofortified wheat grain.

Increasing the concentration of zinc (Zn) in a widely consumed staple food, such as Chinese steamed bread (CSB), is a promising strategy for alleviating Zn malnutrition in humans. The aim of this study, which was based on a 2-year field experiment, was to evaluate the effectiveness of spraying Zn fertilizer combined with commonly applied (i) pesticides and/or (ii) KH2 PO4 (PK) to increase the concentration of Zn and its bioavailability in wheat grain and the CSB derived from it. All the foliar Zn applications (foliar Zn alone or combined with pesticides and PK) significantly increased the concentration of Zn in grain and derived CSB by 69.1% and 63.1%, respectively. Milling caused an 86-88% loss of Zn, while the process of producing CSB caused an 11-26% increase in the concentration of Zn. A net gain of 2.5-8.3 mg Zn kg-1 of CSB was achieved owing to foliar applications of Zn. The concentration of phytic acid (PA) decreased dramatically during milling (89-90%) and the production of CSB (69-72%). As a result, the Zn bioavailability was greater in the CSB than in grain. Foliar applications of Zn also increased the estimated Zn bioavailability of CSB to be as high as 5.5-7.8 mg, which is adequate for human nutrition. Enrichment with Zn had no adverse effects on the quality of CSB. The mixture of foliar Zn with pesticides and PK represents a useful approach to improve the bioavailable Zn of CSB without altering its quality. © 2023 Society of Chemical Industry.

Parâmetros genéticos e validação de marcadores microssatélites associados com ferro e zinco em feijão comum

Abstract The objective of this work was to estimate the genetic parameters, evaluate the agronomic performance, and validate the microsatellite molecular markers (SSRs) linked with quantitative trait loci (QTLs) for Fe and Zn concentrations in grains of common bean, in order to select superior lines. One hundred and sixteen lines from two populations ('BRS Requinte' × 'Porto Real' and 'BRS Requinte' × G2358) and five check genotypes were evaluated in three environments. The parents and lines were genotyped with 20 SSRs. In the simultaneous selection of the lines for the four evaluated traits, the gains from selection were 4.7% for Fe concentration, 2.8% for Zn concentration, 3.9% for yield, and 0.9% for 100-seed weight. Therefore, there is the possibility of selection of lines that combine desirable phenotypes for the traits of interest. The only polymorphic marker is BM 154 in the 'BRS Requinte' × 'Porto Real' population, indicating that the QTLs linked with the markers may already be fixed or that the markers are not associated in the used populations. The single-marker analysis of QTL mapping shows an association between BM 154 and Fe concentration in only one environment, explaining 14.5% of phenotypic variation, which indicates the occurrence of the interaction of QTLs with environments.

Zinc-Based Mineral (ZnSO4·7H2O) and Chelated (Zn-EDTA) Fertilizers improve the Productivity, Quality and Efficiency Indices of Field Pea (Pisum sativum L.) through Biofortification

BackgroundField pea (Pisum sativum L.) is an essential pulse crop which can offer highly nutritional food to human beings. But, the inadequate availability of nutrients such as Zn could pose a significant threat to public health. Thus, there is a need to improve the food quality parameters and nutrient levels of the crop using biofortification thus, making it beneficial for human consumption. MethodsThis study evaluated the influence of zinc (Zn) foliar application on food quality parameters, yield, Zn concentration and its uptake along with the economics of field pea cultivation. In the experiment, different concentrations of ZnSO4·7H2O and Zn-EDTA at the flowering and bud initiation stage were applied to the field pea. ResultsThe foliar application of ZnSO4·7H2O (1.0%) at the flowering and bud initiation stages (treatment T7) was highly efficient in increasing food quality parameters such as crude fibre, TSS, N, K and protein content with maximum values of 3.02, 20.5, 3.15, 3.41 and 14.97%, respectively. Also, the maximum yields of grain and straw in field pea for treatment T7 were 4840 kg ha−1 and 3275 kg ha−1, respectively. Similarly, the maximum Zn concentration in grain (54.8 mg kg−1) and straw (52.5 mg kg−1) of field pea was observed in treatment T7. Additionally, Zn uptake by grain (214 g ha−1) and straw (167 g ha−1) was the maximum for the treatment T7 involving ZnSO4·7H2O (1.0%). Whereas, grain Zn concentration and uptake decreased in the treatments involving the use of Zn-EDTA due to the formation of the complex resulting in the reduced availability of Zn to crop. ConclusionTherefore, the application of ZnSO4·7H2O (1.0%) at the flowering and bud initiation stage significantly improved the food quality parameters, grain and straw yield, concentration of Zn and uptake over control and could be used to alleviate the Zn deficiency in field pea.

Agronomic biofortification increases grain zinc concentration of maize grown under contrasting soil types in Malawi.

Zinc (Zn) deficiency remains a public health problem in Malawi, especially among poor and marginalized rural populations, linked with low dietary intake of Zn due to consumption of staple foods that are low in Zn content. The concentration of Zn in staple cereal grain can be increased through application of Zn-enriched fertilizers, a process called agronomic biofortification or agro-fortification. Field experiments were conducted at three Agricultural Research Station sites to assess the potential of agronomic biofortification to improve Zn concentration in maize grain in Malawi as described in registered report published previously. The hypotheses of the study were (i) that application of Zn-enriched fertilizers would increase in the concentration of Zn in maize grain to benefit dietary requirements of Zn and (ii) that Zn concentration in maize grain and the effectiveness of agronomic biofortification would be different between soil types. At each site two different subsites were used, each corresponding to one of two agriculturally important soil types of Malawi, Lixisols and Vertisols. Within each subsite, three Zn fertilizer rates (1, 30, and 90 kg ha-1) were applied to experimental plots, using standard soil application methods, in a randomized complete block design. The experiment had 10 replicates at each of the three sites as informed by a power analysis from a pilot study, published in the registered report for this experiment, designed to detect a 10% increase in grain Zn concentration at 90 kg ha-1, relative to the concentration at 1kg ha-1. At harvest, maize grain yield and Zn concentration in grain were measured, and Zn uptake by maize grain and Zn harvest index were calculated. At 30 kg ha-1, Zn fertilizer increased maize grain yields by 11% compared with nationally recommended application rate of 1kg ha-1. Grain Zn concentration increased by 15% and uptake by 23% at the application rate of 30 kg ha-1 relative to the national recommendation rate. The effects of Zn fertilizer application rate on the response variables were not dependent on soil type. The current study demonstrates the importance of increasing the national recommendation rate of Zn fertilizer to improve maize yield and increase the Zn nutritional value of the staple crop.

Biogeoaccumulation of zinc in hybrid rice (Oryza sativa L.) in an Inceptisol amended with soil zinc application and its bioavailability to human being

Soil Zn amended is an efficient agronomical Zn biofortification approach in rice. However, it is still need to know if higher rate of Zn over recommended dose can influence other essential nutrient uptake, high accumulation of Zn in soils and health risk for human consumption. This study was conducted by taking ten treatments (T1: control, T2: RDF, T3: RDF + 1.25 mg kg-1, T4: RDF + 2.5 mg kg-1, T5: RDF + 3.75 mg kg-1, T6: RDF + 5 mg kg-1, T7: RDF + 6.25 mg kg-1, T8: RDF + 7.5 mg kg-1, T9: RDF + 8.75 mg kg-1, T10: RDF + 10 mg kg-1) on hybrid rice in Zn (1.20 mg kg-1) enriched soil. The findings have shown that 6.25 mg kg-1 Zn application significantly increased crop growth and grain concentrations of N, K, Zn, Cu and Fe by 71.4, 125, 78.9, 28.5 and 2.4%, respectively. Nutrient harvest index was significantly affected by ranged between 29.1–36.4%. Application of Zn at 6.25 mg kg-1 (T7) recorded the highest Zn concentration in grain (28.2 mg kg-1) and bioavailability of the fortified Zn (2.05 mg Zn day-1). The lowest phytatic acid concentration in grain was recorded in T8 (RDF + Zn at 7.5 mg kg-1) and after that a significant increase was observed. Transfer coefficient was inversely behaving with Zn application and ranged between 6.03–18.0 grain. The average daily intake of Zn was ranged between 0.075–0.118 mg-1 kg-1 day. Across different treatments the Zn build-up factor, geo-accumulation index and soil enrichment factor was ranged between 0.98–4.90, -0.61–1.70 and 0.24–1.82, respectively in post-harvest soil. In conclusion, agronomic biofortification of Zn through soil applications at 6.25 mg Zn kg-1 was a sustainable way to improving growth and grain Zn, N, K, Cu and Fe uptake of hybrid rice to meet human recruitment.

Root Dipping, Foliar and Soil Application of Zinc Increase Growth, Yields, and Grain Zinc in Rice (Oryza sativa L.) Grown in Moderate Zinc Soil of Inceptisol Order

ABSTRACT Zinc (Zn) fertilization not only increased yield of rice but also serves as an economical source of Zn to fight Zn deficiency problems in humans and cattle. A pot experiment was conducted during 2016 (kharif) to study the response of different methods of Zn application on growth, yield, and zinc concentration of rice. Treatments consisted of T1 – without fertilizers (WF); T2 – recommended dose of fertilizer (RDF); T3 – RDF+soil application of 5.0 kg Zn ha−1 (SA5); T4 – RDF + soil application of 7.5 kg Zn ha−1 (SA7.5); T5 – RDF + soil application of 10 kg Zn ha−1 (SA10); T6 – RDF + root dipping in 2% ZnO (RD); T7 – RDF + SA5 + RD; T8 – RDF + foliar application of 0.5% ZnSO4 at tillering and flowering stage (2FA); T9 – RDF + foliar application of 0.5% ZnSO4 at tillering, flowering, and milking stage (3FA); T10 – RDF + SA5 + foliar application of 0.5% ZnSO4 at tillering stage (1FA); T11 – RDF + SA5 + 2FA; and T12 – RDF + SA5 + 3FA. Significantly higher grain and straw yield was obtained in T7 and T6, with a corresponding increase of 17.6 and 30.0% over RDF. Conjoint application of Zn (T7) increased the Zn concentration in grain and straw as compared to RDF, but FA of Zn was more effective than SA. Higher doses of Zn applied increased Zn and manganese (Mn), but decreased the concentration of iron (Fe) and copper (Cu) in grain. Application of 10 kg Zn ha−1 (T5) significantly increased (1.78 folds) the DTPA extractable Zn content in postharvest soil over RDF.

Impact of Zeolite on Protein, Mg and Zn Content of Triticum aestivum L. Wheat in Contaminated Soils of War Zones

Background: Nowadays, the use of unconventional weapons has made a serious damage to the environment. The use of zeolite is one of the solutions in soil pollution management. The aim of this study was to investigate the impact of natural zeolite on grain protein, Mg and Zn uptake in the wheat in contaminated soils by war weapons. Methods: The experiment was carried out in factorial arrangement in a randomized complete design with three replications in a pot. The studied treatments were four levels of zeolite as zero, 0.5, 1.5 and 2.5% based on weight of soil and two types of soils including non-contaminated and contaminated soil by mines and war explosives. Contaminated and non-contaminated soil samples were taken from the southern region of Dehloran city. Results: The results showed that the amount of grain protein and Mg in contaminated soils were significantly higher than non-contaminated soils. The use of zeolite in both soils caused a significant increase in either of them. In this study, the Zn concentration of grain in contaminated soils was higher than non-contaminated. In addition, the concentration of Zn was significantly decreased when zeolite consumption was increased. Conclusion: The results showed that the use of zeolite in contaminated and non-contaminated soils had a positive effect in terms of grain protein and Mg. In addition, the use of zeolite can prevent the excessive increase in Zn due to war weapons and can be effective in plant and community health.

Silicon and Zinc Improves Grain Yield and Nutrient Status in Rice When Supplied During the Different Growth Stages

Silicon (Si) and zinc (Zn) has been recognized as beneficial elements to improve rice (Oryza sativa L.) grain yield. The present study was aimed at investigating the effects of silicon and zinc foliar application at different growth stages on yield components, grain yield, and concentration of silicon and zinc in rice grain. The experiment design was a factorial two-factor randomized complete block design (RCBD) with three replications. Treatments included the fertilizers foliar application at 3 levels (Potassium silicate, Silicon nanoparticles, Zinc Oxide nanoparticles) and rice growth stages at 5 levels (T1: early tillering + middle tillering + late tillering + full heading stage; T2: middle tillering + late tillering + full heading stage; T3: late tillering + full heading stage; T4: late tillering; T5: full heading stage). The results indicated that the application of Si and Zn nanoparticles was superior to potassium silicate in terms of improving the yield components, yield and nutrients concentration in rice grain. Application of Si and Zn nanoparticles increased the grain yield by 7.4 and 4.5%, respectively, above the potassium silicate. Foliar application of nutrients in both T1 and T2 stages led to improved grain yield (7716 and 7700 kg.ha-1 , respectively). The highest Si concentration in grain was obtained by foliar application of nano-Si at the T1 and T2 stages (3.97 and 3.83%, respectively), while the maximum Zn concentration in grain was observed with the nano-Zn application at the T2 stage (21.67 mg.kg-1 ). In general, we suggest applying Si and Zn nanoparticles at the middle tillering + late tillering + full heading stages to improve the yield and rice grain fortifying.

​Yield Attributes, Yield and Nutrient Uptake of Rice (Oryza sativa L.) as Influenced by Zinc Fortified Briquettes in Medium Black Soil

Background: Briquettes is more efficient than conventionally applied nutrients as it reduce the loss of nutrients by obtaining higher yield and decreased the expenditure cost of fertilizers. Indian soils are 49 per cent deficient in zinc which is characterized by widespread Zn deficiency in human beings. Methods: Three different zinc fortified briquettes viz., UB-DAP, UB-suphala and UB-KAB were tested in field experiments during kharif season of 2016-19 to compare and calculate variations in yield, yield attributing characters and nutrients uptake by rice (Oryza sativa L.). Result: The results showed that treatment UB-KAB fortified with 10 kg ZnSO4.7H2O ha-1 (T8) registered higher growth, yield parameters and Zn concentration in grain indicating zinc-sulfate-heptahydrate (ZSHH) offers vital solution to curtail Zn malnutrition. Further, UB-KAB fortified through ZSHH (T8) significantly enhanced the grain (55.2 q ha-1) and straw (63.6 q ha-1) yield of rice over RDF and absolute control. Application of UB-KAB fortified with 10 kg ZnSO4.7H2O ha-1 (T8) significantly increased nutrient uptake of N (97.2 kg ha-1), P (20.2 kg ha-1), K (95.5 kg ha-1), Zn (262.4 g ha-1) and S (53.9 kg ha-1) over fertilizer control (75% RDF) and absolute control. The applications of KAB fortified with zinc sulphate assume great significance in improving rice productivity.

Interactive Effects of Foliar Application of Zinc, Iron and Nitrogen on Productivity and Nutritional Quality of Indian Mustard (Brassica juncea L.)

Indian mustard (Brassica juncea L.) is an important winter oilseed crop in India. It acts as a promising species for the extraction of Zn and Fe under nutrient-deficit conditions. Therefore, this study planned to determine the impact of nutritional supplementation (Zn, Fe and urea) on the productivity and nutritional quality of Indian mustard. In the experiment, different combinations of recommended dose of fertilizer (RDF) with 0.5% FeSO4·7H2O, 0.5% ZnSO4·7H2O and 1% urea at 45 and 60 days after sowing (DAS) were applied to Indian mustard. Foliar application of micronutrients along with urea enhanced the productivity and quality of the crop. Among different treatments, the foliar application of 0.5% FeSO4·7H2O + 0.5% ZnSO4·7H2O + 1% urea (FZU) at 45 and 60 DAS resulted in the maximum increase in grain (27.8%) and stover (34.47%) yield, which was statistically at par with the treatment 0.5% FeSO4·7H2O + 0.5% ZnSO4·7H2O at 45 and 60 DAS (FZ). A similar trend was observed for Zn concentration in grain and stover, as well as Fe concentration in stover. However, the Fe concentration in grain was at maximum with treatment FZU, and the results were significantly higher compared with the treatment FZ. Treatment FZU also resulted in a maximum increase in Zn and Fe uptake in grain (54.7% and 34.3%, respectively) and stover (110.5% and 46.1%, respectively), which was statistically at par with treatment FZ. Physiological efficiencies of Zn (11,838.33) and Fe (3575.887) were highest when only urea was applied along with RDF, whereas the apparent recovery efficiency of Zn and Fe was highest in treatment FZU. Overall, it is concluded that combined foliar application of, 0.5% FeSO4·7H2O + 0.5% ZnSO4·7H2O + 1% urea at 45 and 60 DAS along with RDF was found to be most effective to enhance yield, concentration and uptake of Zn and Fe in Indian mustard.

Foliar application of zinc improves morpho-physiological and antioxidant defense mechanisms, and agronomic grain biofortification of wheat (Triticum aestivum L.) under water stress

Agronomic biofortification with zinc (Zn) may be engaged to improve the nutritious value of food crops along-with tolerance to water deficit conditions. The Zn may increase plant resistance to water stress by boosting physiological and enzymatic antioxidants defense mechanisms. Major objective of this study was to investigate the effect of foliar applied Zn on grain zin biofortification and drought tolerance in wheat. Treatments include application of Zinc at terminal growth phases (BBCH growth stage 49 and BBCH growth stage 65) with five levels: 0 (control-ck), water spray, 5, 10 and 15 mM under two levels of water regimes; well-watered (where 80% water holding capacity (WHC) was maintained in the soil) and water stress, (where 40% WHC was maintained in the soil). Results revealed that water stress significantly reduced relative water contents, gas exchange attributes, plant height, yield and yield related attributes of wheat. In contrast, hydrogen peroxide, free proline levels, activities of malondialdehyde, and concentration of soluble protein were markedly increased under water stress condition. Application of various levels of Zn significantly improved the CAT, SOD, POD and ASP activities at 40% WHC compared with control treatment. Foliarly applied 10 and 15 mM Zn predominantly reduced the damaging impact of water stress by improving the plant status in the form of plant height, RWC and gas exchange attributes. Likewise, wheat plant treated with 10 mM Zn under water stress condition increased the grain yield by improving number of grains per spike, 100 grain weight and biological yield compared with control. Moreover, increasing Zn levels also increased Zn concentration in grains and leaves. Overall, this study suggests that optimum level of Zn (10 mM) might be promising for alleviating the adverse impacts of water stress and enhance the grain biofortification in wheat.

Heterosis and Combining Ability of some Colored Rice Genotypes for Yield Characteristics and Grain Micronutrient Content Using Line X Tester Analysis

Eight exotic colored rice lines and four testers were crossed in line x tester. The resulted 32 F1 hybrids along with their parents were evaluated in a randomized complete block design (RCBD) with three replications at the Experimental Farm of Rice Research Department, Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt during2019 and 2020 growing season, to assess mean performance, general (GCA) and specific (SCA) combining ability as well as identify type of gene action controlling the inheritance of the studied traits. The non-additive gene effects had an important role in the inheritance of all the studied traits more than the additive gene effects. The parental lines Dullar, Black Rice and IRBLKM-TS-[CO] were identified as a good combiners for earliness and KWANG CHANG Ai, Black Rice and Sakha 101 for shortness. Whereas, parental lines: Dullar, Red Rice, IRBLKM-TS-[CO], IRBLTA- CT and Sakha 108 were the best general combiners for grain yield and its components. The hybrid combinations Dullar x Giza 178, Red Rice x Giza 178, B40 x Giza 178, KWANG CHANG Ai x Sakha 108, Dullar x Giza 177 and IRBLTA-CT2 x Sakha 108 had the best SCA effects for grain yield as well as one or more of its components. Moreover, the hybrids Red Rice x Giza 178, IR71567-108-1-2 x Giza177 and B40 x Sakha108 recorded the highest value in Fe and Zn concentrations in grains. These hybrids could be used for improving grain yield and micronutrient content particularly Fe and Zn in rice breeding programs.