Article

Zinc seed coating improves the growth, grain yield and grain biofortification of bread wheat

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Abstract

This study, comprising three independent experiments, was conducted to optimize the zinc (Zn) application through seed coating for improving the productivity and grain biofortification of wheat. Experiment 1 was conducted in petri plates, while experiment 2 was conducted in sand-filled pots to optimize the Zn seed coating using two sources (ZnSO4, ZnCl2) of Zn. In the first two experiments, seeds of two wheat cultivars Lasani-2008 and Faisalabad-2008 were coated with 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 g Zn kg⁻¹ seed using ZnSO4 and ZnCl2 as Zn sources. The results of experiment I revealed that seed coating with 1.25 and 1.50 g Zn kg⁻¹ seed using both sources of Zn improved the seedling emergence. However, seed coated with 1.25 and 1.50 g Zn kg⁻¹ seed using ZnSO4 was better regarding improvement in seedling growth and seedling dry weight. The results of the second experiment indicated that seed coated with 1.25 and 1.50 g Zn kg⁻¹ seed using ZnSO4 improved the seedling emergence and seedling growth of tested wheat cultivars. However, seed coating beyond 1.5 g Zn kg⁻¹ seed using either Zn source suppressed the seedling emergence. Third experiment was carried out in glass house in soil-filled earthen pots. Seeds of both wheat cultivars were coated with pre-optimized treatments (1.25, 1.50 g Zn kg⁻¹ seed) using both Zn sources. Seed coating with all treatments of ZnSO4 and seed coating with 1.25 g Zn kg⁻¹ seed using ZnCl2 improved the seedling emergence and yield-related traits of wheat cultivars. Seed coating with 1.25 g Zn kg⁻¹ seed also improved the chlorophyll a and b contents. Maximum straw Zn contents, before and after anthesis, were recorded from seed coated with 1.5 g Zn kg⁻¹ seed using either Zn source. Increase in grain yield from seed coating followed the sequence 1.25 g Zn kg⁻¹ seed (ZnSO4) >1.25 g Zn kg⁻¹ seed (ZnCl2) >1.5 g Zn kg⁻¹ seed (ZnSO4). However, increase in grain Zn contents from seed coated was 1.5 g Zn kg⁻¹ seed (ZnCl2) >1.25 and 1.5 g Zn kg⁻¹ seed (ZnCl2, ZnSO4) >1.25 g Zn kg⁻¹ seed (ZnSO4). Seed coating with Zn increased the grain Zn contents from 21 to 35 %, while 33–55 % improvement in grain yield was recorded. In conclusion, wheat seeds may be coated with 1.25 g Zn kg⁻¹ seed using either source of Zn for improving the grain yield and grain Zn biofortification.

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... Fertilizer is one of the key factors for improvement of crop yield, agricultural productivity and food security. Fertilizer is mainly delivered through the root to the plant; however, seed coating and the parts above ground are new uptake avenues for delivering nutrients to the plants [3]. The history of research, development, demonstration, popularization and utilization on seed coating agent and seed coating technology in China has lasted for over 20 years [4]. ...
... Zn is a precursor of growth hormone auxin, and adequate Zn supply may be useful for auxin-regulated growth promotion [3]. In our experiment, seed coating with Zn NPs increased significantly the internode length of tomato, the effect of low concentration Zn NPs seed coating was better than high concentration Zn NPs. ...
... Similarly, Youssef and Elamawi [6] noticed that lower concentrations of ZnO NPs (especially 10 and 25 mg/L) enhanced seed germination and improved seedling growth, while higher concentrations (100 and 200 mg/L) resulted in phytotoxicity for plants. Besides, Zn seed coating promotes the growth, grain yield and grain biofortification of bread wheat [3]. So, Zn NPs seed coating could show promise for crop improvement. ...
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Abstract Neutral nanoparticles (NPs) of copper (Cu), iron (Fe) and zinc (Zn) are widely used in agriculture. Polymer seed coating with different metal NPs may supply important nutrients during plant growth and consequently enhances yields. In this research, three kinds of metal NPs were conducted to optimize the optimal concentration through seed coating for improving plant growth and productivity of tomato. Seeds of Venice tomato cultivars were coated by polymer‐based mixture with different concentrations of Cu, Fe and Zn NPs, respectively. At harvest, seed germination, internode length, average weight of single fruit, yield and fruit shape index were measured. When compared with control, the internode length increased by 7.3% and 6.8% with low concentration of Fe NPs and Zn NPs, respectively. The average weight per fruit improved over control by 10.2% and 7.5% with low concentration of Cu NPs and Fe NPs, respectively. The yield with low concentration of Cu NPs and Fe NPs increased the yield by 10.7% and 6.5% compared with control. These results indicated that polymer seed coating with low concentration of metal NPs may promote the uptake of some nutrient and thus improve the productivity of tomato.
... For seed coating, the required substance (e.g. nutrient, chemical, plant growth regulator) is attached to the seed surface as an outer covering (Farooq et al. 2012;Rehman and Farooq 2016). In our previous studies, seed priming of chickpea with 0.001 M Zn solution improved the germination, root and shoot length, seedling dry weight, grain yield and grain Zn concentration of chickpea (Ullah et al. 2019b(Ullah et al. , 2020a. ...
... The total carbohydrate content in chickpea is greater than in other pulses (Haytowitz et al. 2011), and chickpea also contains high bioavailable protein (Yust et al. 2003). Owing to the narrow range of Zn sensitivity, optimisation of Zn rate is needed before wide-scale application under field conditions; seed treatment with higher Zn concentration may inhibit emergence and early seedling growth of plants through Zn toxicity (Rehman and Farooq 2016;Ullah et al. 2019a). ...
... This higher rainfall might had increased the Zn availability of the seed coating; environmental conditions, particularly precipitation, affect nutrient availability (Gregory et al. 2017;Ullah et al. 2020b). Moreover, Zn application increases chlorophyll synthesis and photosynthesis, which improves growth, and biological and grain yields through better photo-assimilation (Liu et al. 2016;Rehman and Farooq 2016;Rehman et al. 2018c). In addition, substantial improvement in pod formation and grain weight contributed to higher grain yield. ...
Article
Chickpea (Cicer arietinum L.) is a leading food legume primarily grown in marginal areas and consumed all over the world. However, its production is limited owing to zinc (Zn) deficiency in many chickpea-based cropping systems. This study was conducted over two years to evaluate the effect of Zn application through seed treatments on productivity and grain Zn biofortification of kabuli and desi chickpea types in Punjab, Pakistan. Pre-optimised doses of Zn were applied as (i) seed priming (0.001 M Zn) and (ii) seed coating (5 mg Zn kg–1 seed), using ZnSO4.7H2O (33% Zn). Hydropriming (soaking in water) and non-primed dry seeds were used as control treatments. Zinc seed treatments significantly improved leghemoglobin contents, nodulation, grain yield, grain Zn yield, grain bioavailable Zn, grain minerals and grain Zn concentration compared with control treatments in both chickpea types. During both years, kabuli chickpea receiving Zn seed coating had higher grain yield (2.22 and 2.73 t ha–1) and grain Zn yield (103 and 129 g ha–1) than kabuli receiving other treatments. Likewise, during both study years, maximum grain bioavailable Zn (4.58 and 4.55 mg Zn day–1) was recorded with Zn seed coating in both chickpea types. Kabuli chickpea had more grain bioavailable Zn than desi. With regard to seed treatments, desi chickpea was more responsive to Zn osmopriming, whereas kabuli was more responsive to Zn seed coating. In conclusion, Zn seed treatments, as seed priming and seed coating, are effective methods for improving the productivity, grain quality and Zn biofortification of both desi and kabuli chickpea.
... However, seed coating has effectively improved production of many crops like barley (Zeļonka et al., 2005) and rice (Tavares et al., 2012). In wheat seed coating with Zn, seed germination, seedling growth and tissue Zn content increases in comparison with uncoated seeds (Rehman and Farooq, 2016). There is limited information to the quantity of Zn fertilizers that can be applied effectively to seeds without injury to the germination seeds. ...
... As indicated above, coated seed with 1.5 g Zn/kg seed had shown a slightly improvement in seed germination when compared to other concentrations and untreated seeds. Rehman and Farooq (2016) pointed out seed coated with Zn improves the seedling weight due to better root and shoot growth. Similarly, Zn coated seed make the nutrient available during the early establishment phase of seed germination and that leaded to faster the seedling growth (Taylor and Harman, 1990). ...
... Moreover, seed coated with the highest dose of Zn 5 g/kg seed had a deleterious effect on seed emergence and seedling growth for both varieties, especially in Altındane variety. Nevertheless, previous studies have noticed the same results reported by Dirginčiutė-Volodkienė and Pečiulytė (2011) and Rehman and Farooq (2016), where that accumulation Zn at high concentration may induce Zn toxicity, which may affect plant growth. ...
... However, seed coating has effectively improved production of many crops like barley (Zeļonka et al., 2005) and rice (Tavares et al., 2012). In wheat seed coating with Zn, seed germination, seedling growth and tissue Zn content increases in comparison with uncoated seeds (Rehman and Farooq, 2016). There is limited information to the quantity of Zn fertilizers that can be applied effectively to seeds without injury to the germination seeds. ...
... As indicated above, coated seed with 1.5 g Zn/kg seed had shown a slightly improvement in seed germination when compared to other concentrations and untreated seeds. Rehman and Farooq (2016) pointed out seed coated with Zn improves the seedling weight due to better root and shoot growth. Similarly, Zn coated seed make the nutrient available during the early establishment phase of seed germination and that leaded to faster the seedling growth (Taylor and Harman, 1990). ...
... Moreover, seed coated with the highest dose of Zn 5 g/kg seed had a deleterious effect on seed emergence and seedling growth for both varieties, especially in Altındane variety. Nevertheless, previous studies have noticed the same results reported by Dirginčiutė-Volodkienė and Pečiulytė (2011) and Rehman and Farooq (2016), where that accumulation Zn at high concentration may induce Zn toxicity, which may affect plant growth. ...
... However, seed coating has effectively improved production of many crops like barley (Zeļonka et al., 2005) and rice (Tavares et al., 2012). In wheat seed coating with Zn, seed germination, seedling growth and tissue Zn content increases in comparison with uncoated seeds (Rehman and Farooq, 2016). There is limited information to the quantity of Zn fertilizers that can be applied effectively to seeds without injury to the germination seeds. ...
... As indicated above, coated seed with 1.5 g Zn/kg seed had shown a slightly improvement in seed germination when compared to other concentrations and untreated seeds. Rehman and Farooq (2016) pointed out seed coated with Zn improves the seedling weight due to better root and shoot growth. Similarly, Zn coated seed make the nutrient available during the early establishment phase of seed germination and that leaded to faster the seedling growth (Taylor and Harman, 1990). ...
... Moreover, seed coated with the highest dose of Zn 5 g/kg seed had a deleterious effect on seed emergence and seedling growth for both varieties, especially in Altındane variety. Nevertheless, previous studies have noticed the same results reported by Dirginčiutė-Volodkienė and Pečiulytė (2011) and Rehman and Farooq (2016), where that accumulation Zn at high concentration may induce Zn toxicity, which may affect plant growth. ...
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Bu çalışmada, Zn ile tohum ön uygulamaları (2.5 ve 5 mM) ve tohum kaplamanın (1.5, 2.5 ve 5 g Zn/kg tohum), çinko içerikleri bakımından farklılıklar gösteren Imam (29 mg/kg Zn) ve Altındane (25.5 mg/kg Zn) buğday çeşitlerinde erken büyüme dönemlerinde, tohumların çimlenmesi ve fide büyüme parametreleri üzerine etkileri 20-25°C sıcaklık ve %70 oransal neme sahip kontrollü büyüme odası koşullarında belirlenmiştir. Her uygulamada, tohum çimlenmesini belirlemek için petri kaplarına ve 21 gün boyunca fide büyümesini izlemek için düşük Zn içeriğine sahip 700 g alüvyonlu toprak içeren saksılara üç tekrarlamalı olarak 25’er tohum ekilmiştir. Sonuçlar, düşük dozda (2.5 mM) Zn ile tohum ön uygulama ve destile su ile tohum ön uygulama işlemleriyle karşılaştırıldığında, Zn ile özellikle yüksek dozda (5 mM) tohum ön uygulama işleminin tohumların çimlenme oranı, ortalama çimlenme süresi ve fide büyümesi parametreleri üzerinde her iki buğday çeşidinde de olumlu bir etkiye sahip olduğunu göstermiştir. Zn ile tohum kaplaması, özellikle düşük Zn konsantrasyonlu tohum kaplaması (1.5 g Zn/kg tohumlar) ve daha az Zn içeriğine sahip Altındane çeşidinde olmak üzere, her iki buğday çeşidinde de muamele edilmemiş tohumlara oranla daha iyi tepki vermiş ve çimlenme parametrelerinde artış göstermiştir. Sonuç olarak, tohumların ekim öncesi Zn ile ön uygulamaya ve kaplamaya tabi tutulması, düşük Zn içeriğine sahip çeşitte yüksek olana kıyasla çimlenme ve fide büyüme parametreleri üzerinde daha belirgin etkiye sahip olmuştur. En düşük oranda çinko ile tohum kaplama (1.5 g Zn/kg tohum) buğday fidelerinin gelişimi üzerine olumlu etkileri yanı sıra düşük maliyetli ve çevre kirliliğini önleme bakımından güvenli olmuştur.
... Hence, it is of paramount importance to apply methods such as seed coating with organic material to reduce the effects of water stress and enhance the seed emergence percentage [20]. Some studies have reported increased seed germination uniformity and speed, as well as seedling establishment, under salinity and drought stress conditions using the seed coating method in rice, barley, rye, and wheat [21,22]. ...
... In the present study, coating seeds with the three types of organic matter appeared to prevent chlorophyll degradation under drought stress. Enhanced chlorophyll content under drought stress has been reported in indica rice and bread wheat plants [21,61]. ...
Article
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The application of superabsorbents to soils and seed coatings is a pre-sowing seed treatment method that is commonly used to improve early vigor and establish stability and uniformity under water deficit conditions. To evaluate the interaction of seed coating and superabsorbent on Calotropisprocera L. (milkweed) under water deficit conditions, a greenhouse experiment was conducted. The experiment was conducted with four coating material levels (non-coated seeds and seeds coated with peat moss, vermicompost, and canola residue), four growth medium levels (soil, sand + soil, soil + 2 g superabsorbent, and soil + 4 g superabsorbent), and three field capacity regimes (25, 50%, and 100%) in a completely randomized design factorial arrangement with four replications. Reducing the field capacity from 100 to 25% led to decreased growth (shoot and root dry weights and leaf area) and chlorophyll content. The activities of SOD, CAT, APX antioxidant enzymes, and proline increased under drought stress. The use of superabsorbent polymers in growth media enhanced growth indices and chlorophyll content and decreased the activity of antioxidant enzymes and proline under water deficit conditions. The highest chlorophyll and growth indices were observed when 4 g of superabsorbent was added to the growth medium under drought stress. The application of 4 g of superabsorbent to the growth medium reduced the activity of antioxidant enzymes and proline. The use of seed coatings improved the growth indices, antioxidant enzyme activity, and chlorophyll content under drought stress. The most adaptive morphological and physiological responses to water stress were observed in the vermicompost-coated seeds. The vermicompost coating containing a superabsorbent polymer (4 g/kg soil) proved to be the best for establishing milkweed under mild (50% FC) and severe water deficits (25% FC).
... 16,17 Globally, zinc deficiency affects more than 30% of the population, making it the 11th leading cause of disease or death worldwide and the fifth most common in developing countries. 6,18,19 The efficacy of zinc fertilization (via seed, soil, or leaf treatments) for increasing plant Zn intake has been demonstrated. 6,18,19 In Pakistan, agronomic biofortification has been proven effective in raising grain Zn content, agricultural productivity, and profitability. ...
... 6,18,19 The efficacy of zinc fertilization (via seed, soil, or leaf treatments) for increasing plant Zn intake has been demonstrated. 6,18,19 In Pakistan, agronomic biofortification has been proven effective in raising grain Zn content, agricultural productivity, and profitability. 6,20,21 Experimental evidence has demonstrated that the chemical similarity of cadmium and zinc minerals in soil simplifies their uptake as divalent cations in plants. ...
Article
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Cadmium (Cd) is a toxic heavy metal that significantly threatens plants and the environment. Its toxicity in plants can result in various adverse effects, including reduced growth, altered metabolism, and cell damage. Cadmium can also interfere with nutrient uptake, particularly zinc (Zn), leading to Zn deficiency and further exacerbating Cd toxicity. On the other hand, foliar application of zinc might be a useful strategy to mitigate cadmium (Cd) toxicity in plants. Hence, a pot experiment was conducted with three replications. The wheat plants were treated with various concentrations of Zn as a foliar spray (control, 0.1, 0.2, 0.4, and 0.5%) in Cd-spiked soil in pots. The results showed that foliar use of Zn at 0.4 or 0.5% resulted in higher plant height, grain yield, and dry matter yield than the control group. Using Zn as foliar spray enriched shoot and grain Zn content while reducing Cd content in the shoot and grain. The leaf’s electrolyte leakage (EL) decreased by 15.4, 29.8, 40.7, and 45.9% in the Zn 0.1%, Zn 0.2%, Zn 0.4%, and Zn 0.5% treatments, respectively, compared to the control treatment. Regarding superoxide dismutase (SOD) activity, Zn 0.5% treatment showed a decrease of 42.9% over control. Specifically, the Zn 0.1% showed a 27.2%, Zn 0.2% showed a 56.8%, Zn 0.4% showed a 91.1%, and Zn 0.5% showed a 133.7% increase in total chlorophyll content than control. Based on the results, it is recommended that 0.4% Zn solution may be used for foliar application for enhancing crop productivity and Zn concentration in plants under high Cd stress. Additionally, continued research on the mechanisms of cadmium uptake, transport, and detoxification in plants may lead to the identification of new targets for intervention.
... Seed coating is an effective and cost-effective approach as there is uniform nutrient application when compared to soil fertilization. This method also enhances the seedling growth and productivity of crop (Rehman and Farooq, 2016). Seed coating with trace elements like zinc, molybdenum, iron, boron and manganese are found to be more effective. ...
... The efficiency of this method is based on various factors like chemical used, coating time, type of soil (alkaline or acidic), soil health or fertility status, coating agent, amount of chemical used, etc. (Singh, 2007;IIPR, 2014IIPR, -2015. Rehman and Farooq (2016) in their study quoted that wheat seeds when coated with 1.25 g Zn kg − 1 seed can enhance the grain yield and grain Zn biofortification. ...
... While treatments T 9 , T 10 and T 11 where Zn applied as foliar spray at flowering stage and B sprayed at both stages 25 DAS and at flowering stage respectively, were at par with treatment T 8 . The increase in NAR was due to the role of Zn in remobilization of reserves from foliage to grains (Rehman & Farooq, 2016). Boron was helpful in enhancing NAR in wheat . ...
... Zn application promoted root growth which increased the seed yield by increasing water and nutrients uptake from soil (Rengel, 2001). Rehman and Farooq (2016) documented that pollen tube germination promoted seed set in crops which was the key reason influencing the grain yield. Renukadevi et al. (2002) also reported that spray of B significantly increased seed yield in pulses. ...
... Seed coating is an application of growth regulators, nutrients, and pesticides at the surface of seed through some stick material . The increase in grain yield in many field crops as wheat, rice, chickpea, and cowpea through seed coating has been reported (Masuthi et al., 2009;Rehman and Farooq, 2016;Ullah et al., 2017Ullah et al., , 2018Farooq et al., 2018). The application of zinc seed coating (1.25-1.50 ...
... The application of zinc seed coating (1.25-1.50 g Zn kg -1 seed) in wheat improved the emergence, grain yield, and quality of grains (Rehman and Farooq, 2016). ...
Article
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Bread wheat (Triticum aestivum L.) is the leading staple and strategic food crop in the Sultanate of Oman; however, the national wheat production can meet less than 1% of the domestic requirements. The balance is met through imports from Australia, Canada, Russia, and Argentina. However, reliance on imported wheat alone may put Oman at risk in the event of wheat export bans. Therefore, wheat production needs to be enhanced to ensure national food security. Nonetheless, water deficits, salinity, prolonged droughts, unavailability of stress resilient genotypes, and heatwaves challenge this notion. In this review manuscript, the current status, constraints, and opportunities to improve wheat production in the Sultanate of Oman have been discussed. The major opportunities to improve the wheat production include crop improvement (i.e. development of short duration, high yielding, disease resistant and climate resilient varieties), efficient irrigation system, adoption of conservation agriculture to conserve the resources, strengthening system of certified seed distribution, seed enhancements, and development and dissemination of site-specific production technologies.
... Zinc fertilization through either method (soil, leaf, or seed treatments) is aimed to enhance the plant Zn uptake (Farooq et al., 2012;Rehman and Farooq, 2016;Rehman et al., 2018b,c). In Pakistan, the agronomic biofortification approach has been successful in improving the grain Zn concentration, crop productivity, and profitability (Tables 1, 2; Rehman et al., 2018a,b,d;Ullah et al., 2019Ullah et al., , 2020c. ...
... However, recently, the research on legumes (chickpea and lentil) biofortification has also got attention Ullah et al., 2020a,c,d,e). Farooq and colleagues have optimized several seed treatments (seed coating and seed priming) protocols for micronutrients delivery in rice, wheat, and chickpea along with soil and foliar fertilization in both Laboratory and field environments (Rehman et al., 2015(Rehman et al., , 2018bRehman and Farooq, 2016;Ullah et al., 2019Ullah et al., , 2020a. The seed treatments along with foliar and soil Zn application proved effective in enhancing the productivity and grain Zn concentration in tested crops. ...
Article
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Micronutrient malnutrition (e.g., zinc) is one of the major causes of human disease burden in the developing world. Zinc (Zn) deficiency is highly prevalent in the Pakistani population (22.1%), particularly in women and children (under 5 years) due to low dietary Zn intake. In Pakistan, wheat is the primary staple food and is poor in bioavailable Zn. However, the number of malnourished populations has decreased over the last decade due to multiplied public awareness, accelerated use of Zn fertilizers (particularly in wheat and rice), initiation of several national/international research initiatives focusing on Zn biofortification in staple crops and availability of supplements and Zn fortified meals merchandise, nonetheless a large number of people are facing Zn or other micronutrient deficiencies in the country. There are few reports highlighting the significant increase in daily dietary Zn uptake in population consuming biofortified wheat (Zincol-2016) flour; indicating the positive prospect of biofortification interventions up scaling in lowering the risk of dietary Zn deficiency in rural and marginalized communities. Zinc fertilizer strategy has not only helped in enhancing the grain Zn concentration, but it also helped in improving crop yield with high economic return. In addition, Zn biofortified seeds have exhibited strong inherent ability to withstand abiotic stresses and produce higher grain yield under diverse climatic conditions. However, there are many constraints (soil, environment, genetic diversity, antinutrients concentration, socioeconomic factors etc.) that hinder the success of biofortification interventions. This review highlights the status of Zn deficiency in Pakistan, the success of agronomic and genetic biofortification interventions. It also discusses the economics of agronomic biofortification and cost effectiveness of Zn fertilization in field conditions in Pakistan and the potential of Zn biofortified seeds against abiotic stresses. Furthermore, it also highlights the constraints which limit the sustainability of biofortification interventions.
... There are two common ways of increasing seed nutrient concentration by ST: one of them is SC, and the other is called seed priming (SP), which consists of immersing seeds in a nutrient solution with a specic nutrient concentration for a given time. 1 Both approaches of ST with nutrients have been associated with improved nutrition and, consequently, the development of seedlings in a quicker and uniform manner. 1,3,4 There is increasing interest in ST, especially for supplying micronutrients, including Zn, to plants. 1,2 For example, coating of maize (Zea mays L.), soybean (Glycine max L.), pigeon pea (Cajanus cajan L.) and ladies nger (Abelmoschus esculentus L.) seeds with micro-sized ZnO (ZnO-MPs, <3 mm) and nano-sized ZnO (ZnO-NPs, <100 nm) increased the production of indole-3acetic acid in the seedling roots, resulting in a higher growth rate. ...
... 7 SC of wheat seeds with ZnSO 4 provides better seedling performance when compared to ZnCl 2 . 3 The treatment of soybean seeds with ZnO-MPs and ZnO-NPs increased the seed germination rate and resulted in seedlings with longer roots. On the other hand, ZnSO 4 promoted toxic effects as observed by inhibition of seedling growth. ...
Article
An adequate concentration of zinc in seeds can help in the initial development of plants. ZnO-coating can provide this nutrient to plants from the early stages of growth. However, there is a pressing need for additional studies to enable its safe use. This study aimed to evaluate the elemental distribution over ZnO-treated maize seeds stored for up to 12 months, as well as to map Zn species in the internal seed tissues. Synchrotron radiation micro-X-ray fluorescence spectrometry (SR m-XRF) and micro-X-ray absorption near-edge spectroscopy (m-XANES) were used as analytical tools for this purpose. The highest Zn accumulation site in micro-sized ZnO treated maize seeds is the embryo, mainly close to the black layer. The distribution pattern of Zn, S and P does not change in maize seeds treated with ZnO. Zn mass fractions in the embryo, pericarp and endosperm suggest that after 12 months of storage, Zn absorption is observed in ZnO-treated seeds. In the Zn hotspot, this element is in the form of phytate and in more readily bioavailable forms, such as Zn 3 (PO 4) 2 and cysteine. These findings can yield valuable insights into the advantages of using advanced microanalytical tools to provide important information regarding potential nutrient bioavailability to those interested in biofortification studies.
... Zn stimulates the production of auxin which is directly linked with efficient N uptake as depicted in Fig. 6(a). This efficient N uptake probably contributed towards improved grain yield and other parameters of wheat due to better photosynthesis and translocation of the photosynthates (Rehman and Farooq, 2016). Moreover, photosynthesis activities also increased due to the excessive production of carbonic anhydrase which sequentially maximized the N uptake and grain yield (Wang et al., 2021). ...
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Less than 50% of the applied urea fertilizer is taken up by plants due to poor nitrogen (N) use efficiency which affects overall agricultural productivity and leads to serious environmental and economic problems. Additionally, soils with high salinity might limit zinc (Zn) availability. Low Zn use efficiency (<30%) when applied as synthetic salts, e.g., zinc sulfate has therefore minimized their applicability. Within the past two decades, nanotechnology has gained a lot of interest in the development of effective nano fertilizers with high nutrient use efficiency (NUE). In this perspective, the approach of coating conventional fertilizers with nano materials especially, the ones which are essential nutrients has researched because of their high use efficiency and reduced losses. In this work, a novel and innovative formulation of hybrid nano fertilizer has been prepared for the sustainable release of nutrients. Zinc oxide nanoparticles (ZnO-NPs <50 nm) were incorporated into the biodegradable polymer (gelatin) and coated on urea using a fluidized bed coater. Among all the formulations, GZnSNPs (1.5% gelatin+0.5% elemental Zn as ZnO-NPs) showed a significant delay in urea release (<80 %) after 120 min). The sand column experiment showed sustainable Zn release for GZnSNPs i.e., 2.7 ppm vs. 3.5 ppm (GZnS) after the 6th day. Moreover, a substantial increase in wheat grain yield (6500 kg/ha), N uptake (46.5 kg/ha) and Zn uptake (21.64 g/ha) were observed for fields amended with GZnSNPs. The composition of GZnSNPs was valuable since this attracted the highest return relative to the other treatments. Gelatin supplied small N-containing molecules, resulting in extra value addition with ZnO-NPs thus increasing yield and fertilizer properties more relative to the same amount of elemental Zn given via bulk salt. Therefore, the findings of the current study recommend the use of ZnO-NPs in the agricultural sector without any negative effects on yield and NUE.
... Genetic execution and Zn feeding may also account for the variability in wheat yield components across various cultivars Ramzan et al., 2020;Hassan et al., 2019). Wheat grain zinc levels are mostly determined by the ease with which zinc may be transferred from the plant's vegetative to its reproductive tissues (Rehman et al., 2016;Cakmak, 2008). Findings were consistent with those of Afzal et al. (2017) and Zeidan et al. (2010), who showed that foliar application of Zn maintains a satisfactory concentration in vegetative tissues throughout the bio-fortification of wheat crop at various development stages in field conditions. ...
Article
To address food production challenges and combat heavy metal toxicity, an economically viable and sustainable approach is essential. Cadmium (Cd) contamination poses risks to crops and human health. Leveraging the structural similarity between zinc (Zn) and cadmium, we explored foliar Zn spray's potential to alleviate Cd toxicity and enhance wheat yield. Our field study near Peshawar, Pakistan, during the 2021À2022 winter, employed a split-plot design to investigate Zn's impact on wheat biofortification. Across three wheat varieties (JANBAZ-10, Pirsabak (PS)-2013, PS-2015), four foliar Zn levels (0 %, 0.5 %, 1.0 %, 1.5 % solution) were tested at various growth stages. Pirsabak-2015 exhibited optimal results, with a 1 % foliar Zn treatment producing the highest grain yield (3409 kg ha À1), biological yield (9022 kg ha À1), grains per spike (56), and 1000-grain weight (40.6 g). Application of 1 % biochar also significantly increased grain yield. Zn concentration peaked in grains and leaves with 1.5 % Zn solution, followed by 1.0 % Zn in the PS-2015 cultivar. Moreover , 1 % Zn application enhanced photosynthetic parameters and significantly reduced cadmium concentrations in leaves and grains. Notably, 1.0 % Zn led to improved stress tolerance as indicated by decreased electrolyte leakage and increased superoxide dismutase and peroxidase activities. Applying 1.0 % Zn solution as a foliar spray during different growth stages demonstrates the potential to enhance wheat yield, increase grain Zn content, and mitigate Cd toxicity in Cd-contaminated soil. Further research across diverse cereal crops and climates will help establish 1.0 % Zn foliar spray as an effective Cd stress mitigation strategy.
... Foliar application of Zn is also an effective method and significantly improves grain Zn contents and grain productivity [225]. In this method, a small quantity of Zn is applied; therefore, this method is economical, and it is also considered to be very important to reduce the deleterious impacts of stress [223,227]. Seed coating is another effective method to deliver Zn to plants, and it appreciably increases growth and yield [228]. The application of Zn as nanoparticles has recently emerged as an important approach to deliver Zn to plants. ...
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Salinity stress (SS) is a serious abiotic stress and a major constraint to agricultural productivity across the globe. High SS negatively affects plant growth and yield by altering soil physio-chemical properties and plant physiological, biochemical, and molecular processes. The application of micronutrients is considered an important practice to mitigate the adverse effects of SS. Zinc (Zn) is an important nutrient that plays an imperative role in plant growth, and it could also help alleviate the effects of salt stress. Zn application improves seed germination, seedling growth, water uptake, plant water relations, nutrient uptake, and nutrient homeostasis, therefore improving plant performance and saline conditions. Zn application also protects the photosynthetic apparatus from salinity-induced oxidative stress and improves stomata movement, chlorophyll synthesis, carbon fixation, and osmolytes and hormone accumulation. Moreover, Zn application also increases the synthesis of secondary metabolites and the expression of stress responsive genes and stimulates antioxidant activities to counter the toxic effects of salt stress. Therefore, to better understand the role of Zn in plants under SS, we have discussed the various mechanisms by which Zn induces salinity tolerance in plants. We have also identified diverse research gaps that must be filled in future research programs. The present review article will fill the knowledge gaps on the role of Zn in mitigating salinity stress. This review will also help readers to learn more about the role of Zn and will provide new suggestions on how this knowledge can be used to develop salt tolerance in plants by using Zn.
... [8] The purpose of applying zinc by any method is to increase the absorption of zinc by plants. [9] Agronomic zinc biofortification is a readily used approach for Zn biofortification and zinc sulphate heptahydrate (ZnSO 4 .7H 2 O) is generally used chemical for the purpose. [10][11][12][13] It not only improves the bioavailability of zinc in foods but also increases net economic returns by increasing food production and saves billions of dollars by limiting the risk of zinc deficiency. ...
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The present study is carried out to establish the biofortification of zinc in potato (Solanum tuberosum L.) and tomato (Solanum lycopersicum L.) plants through the application of zinc oxide nanoparticles (ZnONPs). The mycogenic ZnONPs are synthesized by using Aspergillus flavus biomass and characterized to ascertain the size, shape, and concentration of synthesized nanoparticles. The ZnONPs are applied by foliar spray to the field‐grown potato and tomato crops and the biofortification level is recorded by Atomic Absorption Spectroscopy (AAS). A nanotoxicity assessment is done by comparing the amount of cell death and accumulation of reactive oxygen species (ROS) in control and ZnONPs treated plants. The AAS analysis reveals significant accumulation of the zinc in leaves of potato plants but insignificant accumulation is observed in the tubers. However, a significant accumulation of zinc is observed in the leaves and fruits of the tomato plants (p ≤ 0.05). The nanotoxicity evaluation studies show comparable and statistically insignificant toxicity in control plants as compared to plants treated with ZnONPs. The study concludes that biofortification through the means of ZnONPs is a cost‐effective and eco‐friendly approach that can be used as an alternative to the hazardous chemical zinc fertilizers.
... Zn is an essential micro-element with various roles in plant physiology, biochemical processes, activity of numerous enzymes, growth and development have been extensively studied (Cakmak, 2008;Cakmak et al., 2010;Rehman and Farooq, 2016;Rehman et al., 2018;Cakmak and Kutman, 2018;Karimi et al., 2021;Kaur and Garg, 2021;Liao et al., 2022;Sadeghizadeh and Zarea, 2022). Recently, the role of Zn in plant defense against herbivores and pathogens also reviewed by Cabot et al. (2019). ...
Article
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Introduction: Zinc (Zn) as an essential micronutrient and cytokinin as phytohormone not only regulate plant growth but also play fundamental roles in plant tolerance against drought stress. Understating the function and the role of cytokinin in combined with an essential micronutrient, Zn, could improve the choice of a sustainable strategy for improvement of plant drought stress. The objective of this field research was to determine the effect of post-flowering foliar application of ZnSO4 and 6-benzylaminopurine (6-BAP) on grain yield and quality of winter wheat under water deficit condition. Methods: Experiments were conducted under filed condition. Drought was imposed by with holding irrigation at the beginning of flowering till the signs of temporary wilting/leaf rolling appeared, after which all plots were irrigated to field capacity. The foliar treatment consisted of (1) foliar application of water, as control treatment; (2) foliar application of 10 g ha-1 6-BAP; (3) Foliar application of 20 g ha-1 6-BAP; (4) Foliar application of 10 g ha-1 6-BAP plus foliar application of 6 kg ha-1 ZnSO4 solution and (5) foliar application of 10 g ha-1 6-BAP plus foliar application of 6 kg ha-1 ZnSO4 solution 2 days before drought imposition. Data were collected on grain and straw yield, yield attributes, harvest index, flag leaf fresh matter and dry matter weight, TaCKX6-D1 expression, phytic acid content in grains, mycorrhiza colonization rate and succinate dehydrogenase (SD) activity. Results: According to ANOVA, the factor 'Zn' significantly affected leaf relative water content (p < 0.001). Relative water content for plants foliar applied with 6-BAP was not statistically significant. Applying Zn increased yield, straw dry weight, and kernel weight relative to plants sprayed with water alone. Increased grain yield due to foliar application of Zn was associated with decrease in cytokinin oxidase/dehydrogenase (TaCKX) and increase in kernel weight. Results showed that the drought stress significantly decreased 1000-grain weight that was accompanied with over-expression of cytokinin oxidase/dehydrogenase (TaCKX). Foliar application of Zn increased the concentration of Zn in grains. The experimental data on the zinc content of grain indicated no significant difference between the 6-BAP at 10 mg L-1 and control treatment. The phytate to Zn molar ratio was significantly affected by foliar applied Zn, but not significantly by applied 6-BAP. In the present study, SD activity of the hyphae of indigenous arbuscular mycorrhizal fungi (IAMF) associated with plant roots was also assayed. Results disclose that SD activity of IAMF was significantly affected by Zn treatments during grain filling stages. Discussion: In summary, both foliar applied Zn and 6-BAP had the significant effects on all measured parameters in winter wheat. However, spike number, harvest index and mycorrhizal colonization rate were neither significantly affected by Zn nor 6- BAP. Foliar application of Zn at 0.6% (6 kg ha-1) and higher 6-BAP (20 mg L-1 m-2) promoted wheat growth and performances under imposed drought stress condition. Plant that only foliar sprayed with water showed higher level of TaCKX6-D1 expression as compared to Zn treated plants, indicating these plants were more affected by imposed drought relative to those plants treated with Zn. The results of this study provides evidence that a combination of Zn and 6-BAP could be an effective in improvement of drought tolerance of wheat and prevents grain yield from further reduction in terms of quality and quantity due to drought stress.
... In field trials, magneto-priming of seeds relieved salt stress and improved seedling characteristics in barley plants at the early seedling stage (Cheikh et al., 2018). Zn content of grains increased from 21 to 35 percent after nutripriming with ZnSO 4 and ZnCl 2 , respectively at a rate of 1.25 g Zn kg -1 seed, and grain production increased by 33-55 percent (Rehman and Farooq, 2016). All kinds of seed priming, including hydropriming, promote seed germination, according to Choukri et al. (2022). ...
Article
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Fortification of food with mineral micronutrients and micronutrient supplementation occupied the center stage during the two-year-long Corona Pandemic, highlighting the urgent need to focus on micronutrition. Focus has also been intensified on the biofortification (natural assimilation) of mineral micronutrients into food crops using various techniques like agronomic, genetic, or transgenic. Agronomic biofortification is a time-tested method and has been found useful in the fortification of several nutrients in several crops, yet the nutrient use and uptake efficiency of crops has been noted to vary due to different growing conditions like soil type, crop management, fertilizer type, etc. Agronomic biofortification can be an important tool in achieving nutritional security and its importance has recently increased because of climate change related issues, and pandemics such as COVID-19. The introduction of high specialty fertilizers like nano-fertilizers, chelated fertilizers, and water-soluble fertilizers that have high nutrient uptake efficiency and better nutrient translocation to the consumable parts of a crop plant has further improved the effectiveness of agronomic biofortification. Several new agronomic biofortification techniques like nutripriming, foliar application, soilless activation, and mechanized application techniques have further increased the relevance of agronomic biofortification. These new technological advances, along with an increased realization of mineral micronutrient nutrition have reinforced the relevance of agronomic biofortification for global food and nutritional security. The review highlights the advances made in the field of agronomic biofortification via the improved new fertilizer forms, and the emerging techniques that achieve better micronutrient use efficiency of crop plants.
... Seed coating develops ready covering of nutrients around the germinating seeds to ensure the continuous supply of nutrients to the plants (Idrees et al. 2018). It involves adhering the required nutrients to seed surface directly which is economically important (Rehman and Farooq 2016). ...
... This way of Zn application to the seeds increases the rate of germination, growth rate, as well as yield [59]. However, when seeds are treated with a high concentration of Zn (2 g Zn kg −1 seed), seed germination and growth are severely affected [60]. There is another way for plant roots to absorb Zn, in which plant roots are immersed in the suspension of Zn salts [6]. ...
Article
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Abiotic stress factors are considered a serious threat to various growth parameters of crop plants. Stressors such as drought, salinity, and heavy metals (HMs) hamper the chlorophyll content in plants, resulting in low photosynthesis, hinder the integrity of cell membranes, reduce biomass, and overall growth and development of crops which ultimately results in the sharp decline of crop yield. Under such stressful conditions, various strategies are employed to overcome hazardous effects. Application of Zinc (Zn) or Selenium (Se) in different forms is an effective way to alleviate the abiotic stresses in plants. Zn and Se play a pivotal role in enhancing the chlorophyll level to improve photosynthesis, reducing oxidative stress by limiting reactive oxygen species (ROS) production, controlling HMs absorption by plant roots and their accumulation in the plant body, maintaining homeostasis, and alleviating all the detrimental effects caused by abiotic stress factors. The current review is focused on the usefulness of Zn and Se application, their uptake, sensitization, and different defence mechanisms to relieve adverse effects of abiotic stresses (such as drought, salinity, and HMs) on crops. In this connection, research gaps have also been highlighted.
... Seed coating develops ready covering of nutrients around the germinating seeds to ensure the continuous supply of nutrients to the plants (Idrees et al. 2018). It involves adhering the required nutrients to seed surface directly which is economically important (Rehman and Farooq 2016). ...
Article
Boron (B) is a vital micronutrient essential for human and plants. This two-year field study was conducted to check the efficacy of B application methods along with BTB (Bacillus sp. MN54) to improve nodulation, grain yield, profitability, and B biofortification of kabuli chickpea under irrigated and rainfed conditions. The B application methods consisted of seed coating (1.5 g B kg−1 seed), foliar application (25 mg B L−1 of water), soil application (1 kg B ha−1) and osmopriming (1 mg B L−1 of water solution) [water spray, hydropriming and untreated seeds being taken as control], with and without BTB inoculation grown under irrigated (Layyah) and rainfed (Chakwal) conditions. Interactive effects among B application, BTB inoculation and experimental location showed that B osmopriming coupled with BTB strain recorded maximum 1000-grains weight (24%), grain yield (41%) and biological yield (50%) compared with untreated seed under rainfed conditions while it was at par with B soil application. With respect to B-grain concentration, foliar application of B observed more B contents (86%) compared with control. Economic analysis showed that osmopriming of B along with BTB had highest economic return ($1994.3 ha−1) and benefit cost ratio (3.8) during 2020–21 under rainfed condition of Chakwal. Osmopriming of chickpea seed with B, combined with BTB (Bacillus sp. MN54) inoculation improved nodulation, grain yield and biofortification, profitability and B biofortification of kabuli chickpea under rainfed and irrigated condition. Moreover, rainfed conditions of Chakwal proved more productive with respect to chickpea cultivation.
... Seed coating is the most economical method of nutrient application directly to seeds which involves adhering the required nutrients to the seed surface [24,25]. Boron seed coating in chickpea improved grain yield by 25%, whereas B seed coating in tandem with inoculation of boron-tolerant bacteria (BTB) MN54 increased grain yield by 37% compared to untreated seeds [26]. ...
Article
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Chickpeas are rich source of protein and predominantly grown in boron (B)-deficient sandy-loam soils in Pakistan. Boron-tolerant bacteria (BTB) could tolerate higher B levels in soil and increase B availability to the plants. Field trials were conducted under irrigated (district Layyah) and rainfed (district Chakwal) conditions to evaluate the interactive effects of pre-optimized B application methods and BTB (Bacillus sp. MN54) on the nodule’s population, grain quality, productivity, and grain-B concentration in desi chickpea during 2019–2020 and 2020–2021. Boron was applied as soil application (1 kg B ha􀀀1), foliar application (0.025% B), osmopriming (0.001% B), and seed coating (1.5 g B kg􀀀1 seed) with or without BTB inoculation. Untreated seeds receiving no B through any of the methods were regarded as control. The individual and interactive effects (up to three-way interaction of location � BTB inoculation � B application methods) of year, location, B application methods and BTB inoculation significantly altered the growth and yield-related traits of desi chickpea. The fourway interaction of year � location � BTB inoculation � B application methods was non-significant for all recorded growth and yield-related traits. Regarding individual effects, the higher values of growth and yield-related traits were noted for 2020–2021, rainfed location, BTB inoculation and B application through seed priming. Similarly, in two-way interactions 2020–2021 with rainfed location and BTB inoculation, rainfed location with BTB inoculation and osmopriming and osmopriming with BTB inoculation recorded higher values of the growth and yield-related traits. Osmopriming combined with BTB inoculation significantly improved dry matter accumulation and leaf area index in both locations. Boron application through all the methods significantly improved grain quality, yield grain B concentration. The highest grain and biological yields, and nodules’ population were recorded with osmopriming followed by soil application of B combined with BTB inoculation. The highest plant B concentration (75.05%) was recorded with foliar application of B followed by osmopriming (68.73%) combined with BTB inoculation. Moreover, the highest economic returns (USD 2068.5 ha􀀀1) and benefit–cost ratio (3.7%) were recorded with osmopriming + BTB inoculation in 2020–2021 under rainfed conditions. Overall, B application through osmopriming and soil application combined with BTB inoculation could be used to increase productivity and profitability of desi chickpea, whereas foliar application is a better method to enhance grain and plant B concentration.
... Zinc sulphate at the rate of 1.25 g Zn kg À1 of rice seed will be used in the slurry for coating. Bags of polythene will be used to store the air-dried coated seed in the refrigerator at 4°C until used for sowing (Rehman and Farooq, 2016). For soil application, Zn will be directly applied to the soil at the rate of 4 mg ZnSO 4 kg À1 of soil. ...
Article
Management of zinc (Zn) in calcareous soils is a major problem for higher rice growth and yield. Need of time is to introduce environmentally friendly approach for the management of Zn. Inoculation of arbuscular mycorrhizae fungi (AMF) is one of such efficacious technique for enhancing the availability of Zn in these soils. The present study investigated the effect of different Zn application methods i.e., seed coating (SC; 1.25 g Zn/kg seed), seed priming (SP; 0.5 M solution) and soil application (SA; 4 mg ZnSO4/kg soil) alone or in combination with AMF applied in completely randomized design (CRD) on morpho-physiological growth and productivity of rice. Results showed that Zn SA+AMF remained significantly the best treatment for the improvement in germination, plant height, spike length and number of spikes than control+AMF and control with no AMF. A significant enhancement in 1000 grains weight (71.11%), total chlorophyll (40.38%), photosynthetic rate (16.17%) and transpiration rate (41.48%) validated the efficacious role of Zn SA+AMF over control+AMF. Significant increase in rice grains N (25.68 and 40.11%), P (29.41 and 25.00%), K (42.86 and 47.37%) and Zn (10.42 and 59.03%) signified the imperative functioning of Zn SA+AMF and Zn SA over control+AMF and control without AMF respectively. In conclusion, Zn SA has the potential to improve the rice growth nutrients uptake. However, Zn SA+AMF is better to approach than the sole application of Zn SA for rice. More investigations at the field level under different soil textures are suggested to declare Zn SA+AMF as the best treatment for improvement in the productivity of rice.
... Imran et al. (2017) found under controlled conditions that soybean plants whose seeds were treated with zinc grew as plants to which zinc was provided in the form of a nutrient solution. Rehman and Farooq (2016) found that wheat grain yield can be increased by 33-35% and zinc content in grain up to 25% if wheat seeds are treated with 1.25 and 1.50 kg Zn 2+ /ha (ZnSO 4 ) before sowing. Esper Neto et al. (2020) found that maize plants whose seeds were treated with zinc oxide nanoparticles before sowing had more intensive germination and greater resistance to stress conditions. ...
Article
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Maize production is intensified with a larger amount of mineral fertilisers in the era of meteorological conditions change, which leads to a decrease in the reserves of microelements in the soil. The aim of this study was to determine the influence of zinc application on grain yield, nitrogen and carbon content in grain of three maize genotypes in the period 2016–2018 (factor A). Factor B: cultivars ZP 427, ZP 548 and ZP 687 belonging to different maturation groups. Factor C: Various zinc treatments were applied: T1 – control; T2 – 25 kg Zn2+/ha (35 g of ZnSO4 on the experimental plot) was introduced into the soil before sowing; T3 – seed treatment (0.129 g of ZnSO4 • 7 H2O) + foliar treatment (2 L/ha liquid fertiliser 7% Zn2+). The average yield for all examined variables was 7.33 t/ha. On average, T2 (8.08 t/ha) treatment showed a highly significant effect on the yield in relation to T1 (7.03 t/ha) and on T3 (7.21 t/ha). On average, the amount of nitrogen determined for all cultivars was the highest in T3 (1.52%). The highest carbon content was in T1 (41.78%), which is at the level of significance of P < 0.01 more than T2 (41.46%), while in relation to T3 (40.99%) there is no significance.
... Higher seedling length was observed in tomato seeds coated with a combination of talc, calcium oxide and bentonite . Application of micronutrients as seed coating also showed higher values for seedling growth and development as compared to control (Rehman and Farooq, 2016). Similar results were also observed in zinc coated chickpea seeds, but negative relation was observed between higher concentration of coating agent and seedling growth (Ullah et al., 2019). ...
Article
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Crop establishment is the most important phenological stage in the life cycle of crop plants which is governed by the pre-sowing quality of seed. From harvesting to sowing, a broad range of factors including genomics and prevailing environmental conditions can have marked influence on the quality of seed. These factors solely or in combination can cause a huge financial loss. However, control of all these factors for improving seed quality is a difficult task for the farmers to accomplish, however, some of the factors could be controlled. To tackle the issue, physical properties of seed are modified by the exogenous application of certain physical, chemical or biological compounds directly to the surface of a natural seed coat. Application of coatings through seed coating improves germinates phases, advances phenological events, enhances physio-morphological attributes, yield and most importantly the restoration efficacy of seed. In addition, seed coating offers an attractive option as a tool for enhancing crop establishment by propelling the challenges faced to agricultural systems and restoration of degraded systems. This review summarizes comprehensive information on various seed coating technologies and their potential role for achieving a cost-effective ecosystem by increasing food security.
... Wheat grain ZnTotal concentration currently has an approximate average value of 28 -30 mg kg -1 , with the aim to increase it to 40 -50 mg kg -1 [382]. Studies have looked into achieving this in many different ways, including: enriching seeds with zinc [384][385][386]; the addition of biostimulants such as fulvic acid, seaweed extract and amino acids [387]; the use of green manure [388,389]; biofortication and selective breeding of wheat cultivars [390]; and inoculation with non-indigenous AMF strains [388]. Other investigations into wheat grain zinc enhancement have explored the effect of different soil nutrients [391], sewage sludge application [392], the impact of different farming systems [393,394], zinc application rate to soil [395] and the mode of zinc application ...
Article
Nanoparticles (NPs) are materials that have at least one dimension between 1 – 100 nm. Zinc oxide (ZnO) NPs have properties such as UV-light absorption that make them suitable for adding to personal care products. Many ZnO NP-containing products are routinely rinsed into household wastewater and the resulting zinc NP-containing biosolids frequently used to fertilise agricultural soils. This thesis aimed to investigate potential methods to detect and analyse zinc NPs in natural soil environments as a result of biosolid application. For this, two different strategies were used. The first intended to look at the mechanism of zinc NP dissolution and fixation in soils by developing methods based on dialysis and size exclusion chromatography (SEC). The second aimed to grow plants on soils spiked with different zinc NPs in order to observe differences in various parameters. Preliminary experimental work focused on method development and determined that NPs can exhibit different behaviours in different solutions and can readily adsorb to equipment surfaces. It was also found that SEC suffered severely from zinc NP column adsorption which persisted despite many attempts to rectify the issue and attempts to use dialysis experienced similar issues. Following this, experimental work shifted focus to investigate the different behaviours of ZnO NPs, ZnSO4, ZnS NPs and Zn3(PO4)2 in soil and ryegrass. Pristine ZnO NPs were shown to dissolve quickly in soil and followed a similar pattern to ZnSO4 for ZnDTPA, but sequential fractionation results revealed that they behaved differently to ZnSO4. ZnO NPs also reacted differently to aged ZnS NP and Zn3(PO4)2 particles, which did dissolve, but very slowly. This experiment indicated that ZnS NPs could potentially be safe for crops while still providing nutrition, which would make them useful as a potential method of fertilisation. The next experiment examined the same four zinc species with AMF and wheat. Results suggested that ZnS NPs could potentially provide a long-term supply of zinc that supports the biofortification of cereal grains while also avoiding issues of toxicity that can be associated with ZnSO4 or ZnO NP fertilisers. Overall, both these experiments highlighted that it is not applicable to test ZnO NPs and subsequently apply the results to aged particles. Studies using ZnO NPs are likely to observe fast NP dissolution and high zinc availability, potentially leading to concerns over zinc toxicity that may not have been raised if appropriately aged particles had been used instead.
... The coating of wheat seeds with zinc salts (chlorides and sulfate) positively affects germination capacity, stem and root length, plant dry matter, and Zn content in wheat grain. The addition of sulfate is more beneficial to plants because Clions can have an inhibitory effect on plant growth [38]. The positive effect of micronutrients (Zn, B, Mo, Cu, Fe, and Mn) introduced into the maize seed coat along with PGPR bacteria (plant growth-promoting rhizobacteria) was demonstrated in a study by Saadat et al. ...
Article
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Seed coating containing fertilizer nutrients and plant growth biostimulants is an innovative technique for precision agriculture. Nutrient delivery can also be conducted through multilayer seed coating. For this purpose, sodium alginate with NPK, which was selected in a preliminary selection study, crosslinked with divalent ions (Cu(II), Mn(II), Zn(II)) as a source of fertilizer micronutrients, was used to produce seed coating. The seeds were additionally coated with a solution containing amino acids derived from high-protein material. Amino acids can be obtained by alkaline hydrolysis of mealworm larvae (Gly 71.2 ± 0.6 mM, Glu 55.8 ± 1.3 mM, Pro 48.8 ± 1.5 mM, Ser 31.4 ± 1.5 mM). The formulations were applied in different doses per 100 g of seeds: 35 mL, 70 mL, 105 mL, and 140 mL. SEM-EDX surface analysis showed that 70 mL of formulation/100 g of seeds formed a continuity of coatings but did not result in a uniform distribution of components on the surface. Extraction tests proved simultaneous low leaching of nutrients into water (max. 10%), showing a slow release pattern. There occurred high bioavailability of fertilizer nutrients (even up to 100%). Pot tests on cucumbers (Cornichon de Paris) confirmed the new method’s effectiveness, yielding a 50% higher fresh sprout weight and four times greater root length than uncoated seeds. Seed coating with hydrogel has a high potential for commercial application, stimulating the early growth of plants and thus leading to higher crop yields.
... Agronomic biofortification is an easy, quick, affordable and less technical approach to enhance the concentration and bioavailability of micronutrients in food crops, thereby is helpful to eliminate widespread Zn deficiency (Cakmak and Kutman, 2018). Agronomic biofortification can be achieved by Zn fertilization, which can be made via soil or foliar techniques (Rehman and Farooq 2016). Both these techniques have proven effective for enhancing concentration of Zn in cereals (Perera et al., 2018;). ...
Article
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Zinc (Zn) malnutrition in humans can be minimized by agronomic biofortification of cereal crops. Hence, a field experiment was executed to study the effects of Zn fertilization techniques on grain yield, Zn concentration and bioavailability in rice grains of two genotypes (NIA-Mehran and Shandar). The treatments involved control (No Zn), soil application (10 kg Zn ha- 1), foliar application twice (0.3% Zn at booting, and one week after flowering), and foliar application thrice (0.3% Zn at booting, one week and two weeks after flowering). The Zn fertilization enhanced grain yield to 30%, Zn concentration in polished rice up to 3.3 times and 2.5 times in brown rice, while decreased phytic acid (PA) concentration to 40.7% over control treatment. The Zn application enhanced Zn bioavailability by lowering PA: Zn molar ratios to 79% in polished rice, 69% in brown rice, and increased total daily absorbed Zn (TAZ) to 4.7 times in polished rice and 3.7 times in brown rice over control. Among Zn applications, the maximum grain yield (9.11 ± 0.03 t ha-1), Zn concentrations (32.17 ± 0.37 mg kg-1 in polished rice and 55.74 ± 0.33 mg kg-1 in brown rice) and TAZ (1.03 ± 0.35 mg Zn day-1 in polished rice and 1.65 ± 0.03 mg Zn day-1 in brown rice) while the lesser PA concentrations (8.49 ± 0.05 g kg-1 in polished rice and 9.76 ± 0.33 g kg-1) and PA to Zn molar ratios (27.40 ± 0.24 in polished rice and 17.24 ± 0.34 in brown rice) were recorded with foliar application thrice. The target level of Zn in polished rice for effective biofortification (28 mg kg-1), and the minimum PA: Zn molar ratio (< 18) was nearly met in brown rice with foliar fertilization (3x). The required TAZ (3 mg Zn day-1) was covered up to 53% with ingestion of brown rice and 33% with polished rice. Both genotypes performed similar for grain yield, Zn and PA concentrations, and Zn bioavailability parameters. We recommend that foliar Zn fertilization should be adopted in rice husbandry and humans should preferably consume brown rice to minimize Zn malnutrition.
... Process of seed germination involves three primary steps, viz., (I) seed hydration, (II) activation of metabolic events, and (III) cell lengthening and the emergence of radicle from the seed. Seed priming is a simple, economical, less time-consuming technique which ensures the superior emergence of seedling, equal stand establishment, hasten flowering and, ultimately, healthier crop yields (Rehman and Farooq, 2016;Ullah et al., 2019a). Basically, seed priming involves the hydration of a seed to a level, i.e., required for the activation of metabolic activities but not adequate for the protrusion of radicle. ...
Chapter
In the present days, biopriming serves as a novel method for treatment of seeds adversely affected by several seeds/soilborne pathogens present in the rhizosphere. Treatment of seeds with such BCAs either fungal or bacterial offer an important means of controlling several devastating seed and soil originated diseases. Seed bio-priming integrates biological (treatment of seed with useful organism) and physiological aspects (seed hydration) of seed germination and thereby present a better management approach against numerous fungal and bacterial pathogens in comparison to stereotype chemical treatments. Moreover, it is an eco-friendly and cost-effective methodology which utilize the expertise of certain useful fungal and bacterial antagonists to protect plants from lethal pathogens. Therefore, no doubt, this approach may provide an effective substitute to unlimited reckless use of pesticides. In many agricultural and horticultural crops, seed priming was used as the best tool to enhance germination rate and uniformity. Therefore, seed priming alone or in combination with compatible fungicides and/or biocontrol has been used to improve the rate and uniformity emergence of seed and decrease many seedborne disease.
... Plant Zn demand can be fulfilled by application of Zn through leaf, soil and seed invigoration techniques (pre-sowing seed priming and seed coating) (Farooq et al., 2012). In seed priming, seeds are soaked in aerated water (hydropriming) or solution containing nutrients or growth regulators (Farooq et al., 2012(Farooq et al., , 2020a; while a thin layer of nutrient/growth regulators is adhered over seed surface in seed coating using some sticky inert material (Farooq et al., 2012;Rehman and Farooq, 2016). However, leaf and soil fertilization are not ecofriendly and have limited effectiveness (Fageria et al., 2009). ...
Article
Faba bean (Vicia faba L.) productivity is limited by drought stress and is often associated with mineral nutrient deficiencies such as zinc (Zn). Three independent experiments were conducted to optimize Zn application and its role in tolerance against drought in faba bean. In the first experiment, faba bean seeds soaked in aerated 0.001, 0.01, 0.05, 0.1 and 0.5 M Zn solutions (osmopriming) or water (hydropriming) for 12 h were sown in Petri plates in a growth chamber. Based on the results, in the second and third experiments, faba bean seeds were subjected to osmopriming with 0.001 M Zn solution and hydropriming followed by surface drying and re-drying of seed to the original weight. In third experiment, treated faba bean seeds were planted in peat moss-filled pots maintained at 75 % water holding capacity (WHC) (well-watered) or 50 % WHC (drought stress). In the first study, seeds primed with high Zn concentration (≥ 0.01 M Zn) did not germinate. Drought stress suppressed the seedling emergence, growth with enhanced oxidative stress. However, seed priming with 0.001 M Zn solution followed by surface drying ameliorated the adverse effect of drought stress by increasing the biomass production (99.8 %), leaf area (23 %), α amylase activity (85 %), soluble sugar (54.7 %), Soil Plant Analysis Development (SPAD) value (48.7 %), leaf Zn concentration (79.8 %) with reduction in leaf malondialdehyde (42.7 %) content and total antioxidant activities (35.2 %) under drought stress compared to untreated control. Conclusively, adequate Zn supply through seed priming can help in ameliorating the adverse effect of drought stress in faba bean during the early seedling growth stage.
... All fertilizers were synthetic chemicals, but several are available as organically approved. Zinc oxide [75,76] and zinc sulphate [70,[77][78][79][80] are the most promising micronutrients used in seed coating of cereal crops and pulses. Wiatrak [81,82] evaluated the effect of polymer coating with manganese, copper and zinc on wheat and soybean crops and found a cost-effective technique for the enhancement of plant growth and ultimate yield of both crops [81,82]. ...
Article
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The objective of modern seed-coating technology is to uniformly apply a wide range of active components (ingredients) onto crop seeds at desired dosages so as to facilitate sowing and enhance crop performance. There are three major types of seed treating/coating equipment: dry powder applicator, rotary pan, and pelleting pan with the provisions to apply dry powders, liquids, or a combination of both. Additional terms for coatings produced from these types of equipment include dry coating, seed dressing, film coating, encrustments, and seed pelleting. The seed weight increases for these different coating methods ranges from <0.05% to >5000% (>100,000-fold range). Modern coating technology provides a delivery system for many other materials including biostimulants, nutrients, and plant protectants. This review summarizes seed coating technologies and their potential benefits to enhance seed performance, improve crop establishment, and provide early season pest management for sustainable agricultural systems.
... Micronutrient application as seed treatment successfully delivers the nutrients aimed for growth and yield enhancement [165]. However, seed treatments with higher Zn (2 g Zn kg −1 seed) concentration significant inhibit seed germination and subsequent growth [166]. Thus, in view of a suitable scale of Zn application through seed priming, it is necessary to optimize the level of application. ...
Article
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Drought stress affects plant growth and development by altering physiological and biochemical processes resulting in reduced crop productivity. Zinc (Zn) is an essential micronutrient that plays fundamental roles in crop resistance against the drought stress by regulating various physiological and molecular mechanisms. Under drought stress, Zn application improves seed germination, plant water relations, cell membrane stability, osmolyte accumulation, stomatal regulation, water use efficiency and photosynthesis, thus resulting in significantly better plant performance. Moreover, Zn interacts with plant hormones, increases the expression of stress proteins and stimulates the antioxidant enzymes for counteracting drought effects. To better appraise the potential benefits arising from optimum Zn nutrition, in the present review we discuss the role of Zn in plants under drought stress. Our aim is to provide a complete, updated picture in order to orientate future research directions on this topic.
... Apart from foliar and or soil fertilization, seed priming increased the zinc content of crops, including vegetables. Seed coating using two different sources of Zn (ZnSO 4 and ZnCl 2 at the rate of 1.25 g Zn/kg seed) increased the grain Zn contents from 21% to 35%, while grain yield improved about 33%-55% (Rehman and Farooq, 2016) thus improving the grain yield and grain Zn biofortification. Seed priming of Zn and endophytic bacteria improved grain productivity and grain biofortification of bread wheat (Rehman et al., 2018). ...
Chapter
Iron (Fe), zinc (Zn), and selenium (Se) are essential micronutrients for both plants and humans. Micronutrients from soil move to the plants and finally reach the animals, and humans. Intensive agriculture has led to a decrease in soil quality, and two-third of the soils across the world are micronutrient deficient. Crops cultivated on such soils make them severely micronutrient deficient, causing “micronutrient malnutrition” in humans. Nutritional quality of grains is an essential aspect of food security as micronutrient-imbalanced diet can lead to a variety of non-communicable disorders and decrease the overall immune status. Micronutrient-enriched cereals can provide the “more” and not just the protein and calories, thus providing a sustainable solution to the problem of “hidden hunger.” Research on genetic biofortification and introduction of “transgenic crops” with better micronutrient uptake characteristic has to be complemented by agronomic biofortification for “quick” enrichment of micronutrients. Studies on a global scale prove the utility of agronomic biofortification of cereals, millets, and pulses to overcome Fe, Zn, and Se deficiencies. Research on the use of conventional as well as newer nanotechnology-based soil- as well as foliar-applied fertilizers is on the forefront. Ensuring maximum “nutrient-use efficiency” while causing minimal harmful/damaging effects on the environment is the need of the hour. Efforts at the restoration of soil quality and managing the biotic components also lead to positive biofortification outcomes. Moreover, understanding of the mobilization of the soil and/or foliar-applied micronutrient can help in identifying molecular targets for genetic biofortification. Upon establishing bioavailability of the enriched nutrient, the participation of farmers and policy-makers for successful implementation of the technologies developed in laboratories is exceptionally crucial.
... In plants, Zn can be applied through various methods like seed treatment (seed priming, seed coating), soil application, and foliar application (Rehman and Farooq 2016;Farooq et al. 2018;Haider et al. 2019;Ullah et al. 2020). Seed priming techniques have been developed to improve seed capacity for better germination and early growth. ...
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Mungbean (Vigna radiata (L.) Wilczek) is grown worldwide because of its high protein contents, but its production is low due to zinc (Zn) deficiency in soil. This study was conducted to assess the best mungbean genotype and Zn application method to enhance productivity and grain Zn biofortification. Two mungbean genotypes NM-92 and NM-2006 were grown using three Zn application methods and their combinations, viz. osmopriming (0.01 M), soil application (10 kg ha−1), foliar application (0.5%), osmopriming + soil, osmopriming + foliar, foliar + soil, and osmopriming + foliar + soil, whereas hydropriming and no Zn application were used as control. The results indicated that stand establishment, allometric traits, grain yield, grain biofortification, net income, and benefit-cost ratio were more in genotype NM-92 at both sites (Layyah and Multan). In pot experiment, Zn osmopriming + foliar application enhanced grain yield (90.3%) and osmopriming + foliar + soil Zn increased grain Zn concentration (45.1%) in genotype NM-92. Among the sites, at Layyah, Zn soil application + foliar enhanced grain yield (63%) and the combination of osmopriming + foliar + soil increased grain Zn concentration (79%) in genotype NM-92. At Multan site, the grain yield and grain Zn concentration were enhanced by 63.7% and 31.6%, respectively, in genotype “NM-92” with Zn soil application + foliar. The highest marginal net benefits were obtained with Zn foliar + soil application at both sites in mungbean genotype NM-92. The genotype NM-92 should be planted with Zn application as osmopriming + foliar + soil to attain better yield and grain Zn biofortification.
... It is an effective alternative to foliar and soil applications of micronutrients . Zinc application via seed treatments improves seedling growth and grain Zn concentrations (Rehman et al. 2015(Rehman et al. , 2018b(Rehman et al. , 2018dRehman and Farooq 2016;Farooq et al. 2018;Ullah et al. 2019aUllah et al. , 2019bUllah et al. , 2019c. ...
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Chickpea (Cicer arietinum L.) is an important grain legume that is grown and consumed all over the world. Chickpea productivity is affected by micronutrient deficiencies in soil, particularly zinc (Zn). Chickpea is mostly grown in rainfed areas and marginal soils with low available Zn. Zinc is a structural constituent and regulatory cofactor of enzymes involved in various plant biochemical pathways. Zinc deficiency impairs plant growth and development by reducing enzyme activity, disturbing ribosomal stabilization, and decreasing the rate of protein synthesis. Moreover, Zn deficiency induces flower abortion and ovule infertility leading to low seed set and substantial yield reductions. Nonetheless, chickpea inclusion in cropping systems (e.g., rice–wheat), either in rotation or intercropped with cereals, improves Zn availability in the soil through the release of phosphatases, carboxylates, and protons by roots and soil microbes. This review discusses the role of Zn in chickpea biology, various factors affecting Zn availability, and Zn dynamics in soil and chickpea-based cropping systems. The review also covers innovative breeding strategies for developing Zn-efficient varieties, biofortification, and agronomic approaches for managing Zn deficiency in chickpea. Strategies to improve grain yield and grain Zn concentration in chickpea using different application methods—soil, foliar and seed treatments—that are simple, efficient and cost-effective for farmers are also discussed. The screening of efficient genotypes for root Zn uptake and translocation to the grain should be included in breeding programs to develop Zn-efficient chickpea genotypes.
... Literature data show that the most commonly used metal complexes are EDTA or DPTA, but increasingly there appear scientific reports on fully biodegradable chelates obtained by complexing microelements by functional groups of proteins (Carmen et al., 2009;Liu et al., 2009;Zhang et al., 2016). More often, nutrients are given to plants in hydroponic systems (Abdelhameed et al., 2019;Moncada et al., 2018), via seeds coating (Barua et al., 2018;Farooq et al., 2018;Rehman and Farooq, 2016) and seed priming (Barua et al., 2018;Chattha et al., 2017). There are also other unconventional ways of applying trace elements that are essential for plants, such as hydrolyzed wool (Gogos et al., 2013) or fertilizers based on plants that are hyperaccumulators of a specific element (Bañuelos et al., 2015;Bocchini et al., 2018). ...
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The rapid growth of the global population and the resulting need to ensure sufficient food safety in highly productive agricultural practices. Intensive cultivation of plants contributes to the impoverishment of soils and thus forces farmers to apply intensive fertilization with microelements. Precise fertilization techniques are the future of agriculture, in which nutrients are supplied in controlled way with minimized losses to the environment, caused by leaching to groundwater. Kinetics of nutrients release should be thus adjusted to plant requirements and kinetics of uptake by the plant. The paper presents current achievements in the field of fertilizers with controlled release of microelements, which, apart from the main fertilizer components, are also very significant for proper plant growth. Fertilizers are divided into four basic groups, which include low-solubility fertilizers, fertilizers with external coating, bio-based and nano-fertilizers. Despite structural differences, all groups show properties of controlled microelement release. The paper presents new fertilization technologies with consideration of their influence on the environment.
... Enrichment of edible parts of plants and increase of the bioavailability of micronutrients are also obtained by non-conventional methods. Often mentioned here are genes manipulation or genotypes selection (Hidoto et al., 2017;Johnson et al., 2011;Kumar et al., 2016;Neeraja et al., 2018), hydroponic breeding (Barrameda-Medina et al., 2017;Sida-Arreola et al., 2017;Wu et al., 2007), nanoparticles (Liu and Lal, 2015), seeds coating (Rehman and Farooq, 2016) and the use of biofertilizers containing bacterial strains capable of solubilizing micronutrient compounds present in the soil (Khande et al., 2017;Mumtaz et al., 2017;Ramesh et al., 2014;Shaikh and Saraf, 2017). Sewage sludge (Mcgrath et al., 2012), biomass ash and biogas digestate (Przygocka-Cyna et al., 2018) or hydrolyzed wool (Gogos et al., 2013) are increasingly used for plant supplementation with microelements. ...
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This paper reports the studies on the elaboration of new environmentally friendly fertilizer obtained by valorization of post-extraction biomass residues of alfalfa (Medicago) and goldenrod (Solidago), after extraction with supercritical carbon dioxide, via biosorption process. The performance and controlled release properties of fertilizer were assessed in laboratory under in vitro and in vivo conditions, as well as on the field. In vitro tests show high bioavailability of micronutrients (Cu, Mn, Zn) administered on the biological carrier - between 60 and 80%, in relation to 100% availability of sulphate microelements. This phenomenon is desirable and indicates slowed release pattern of micronutrients. Germination tests demonstrated the phytotoxicity effect of sulphates, while yield increase and biofortification effect by the use of new fertilizers was achieved. Field trials showed, that with respect to conventional micronutrient fertilizers (mineral salts), fertilizers obtained via biosorption resulted in increase of the content of Cu, Mn and Zn by 2.6, 88.6 and 50.6% in plant biomass, respectively. This is important from the point of view of plant and animal nutrition. In addition, the uptake of fertilizer components was calculated, indicating their degree of use. Calculations of micronutrient uptake in field trials shows a higher uptake of fertilizing microelements of products obtained via biosorption by 4.04% (Zn), 1.47% (Cu) and 20.63% (Mn) in relation to sulphates.
Chapter
Malnutrition or micronutrient deficiency is a global concern particularly in developing countries mainly due to its associated health problems. Globally, two billion people are at risk of malnutrition especially children under the age of five and pregnant women especially living in South Asia and Africa. The nutritional quality or dietary requirement is largely compromised due to lack of diversity in diet. Moreover, intake of micronutrient-deficient legume-based crops is an additional threat to global nutritional security. Hence, it is recommended to implement some cost-effective and feasible approaches in global food system to address nutritional security issues for this rapidly increasing human population. This chapter focuses on the significance of biofortification of legume-based crops as an approach to enhance crop productivity and provide viable solution to address the issues of micronutrient deficiencies. In this attempt, various innovative agronomic and cultural biofortification techniques like ferti-fortification, foliar fortification, integrated soil fertility management, seed priming, seed coating, application of different soil amendments, suitable cropping systems, and use of green technology have been discussed in detail. These approaches significantly improved nutrient contents of targeted crops without affecting their agronomic productivity. Moreover, apart from quantitative traits, these biofortification techniques also improved the qualitative traits of crops to better alleviate hidden hunger. Thus, this chapter provides useful insights for researchers regarding the potential of these biofortification techniques to enhance crop yield and their enrichment with additional micronutrients.
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The initial growth phase of agricultural plants, called crop establishment, is crucial and influenced by the quality of the seed used. Seed quality can be affected by various aspects such as genetics and environmental situations, foremost to financial losses for farmers. It is challenging for farmers to control all these factors, but seed coating technology can help by applying physical, chemical, or biological components to the seed surface to enhance its physical properties. Seed coating techniques such as pelleting, encrusting, and film coating increase seed weight and improve crop performance. Seed coating can be a useful means for addressing agricultural challenges and restoring degraded systems, ultimately contributing to improved food security and a more cost-effective ecosystem. This paper provides evidence on different seed coating technologies and discusses their possible benefits.
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Zinc (Zn) malnutrition is a serious public health issue across the world and is mostly caused by inadequate dietary intake of micronutrients—particularly Zn. Its deficiency in humans might be resolved by improving their bioavailability in food items consumed at large for instance cereals, pulses etc. Mungbean, being an utmost important pulse crop grown worldwide, would play a significant role to ameliorate Zn deficiency amongst vegetarian population of the world. Besides this, Zn application also helps to enhance mungbean productivity and livelihood of farmers. Keeping this in view, the current study was conducted during 2021 and 2022 in randomised complete block design (RCBD) with four replications and the effect of soil and/or foliar application of Zn at flower initiation and/or pod formation on grain yield and Zn accumulation in mungbean grains were assessed. On the basis of 2-year pooled mean data, soil application of ZnSO4 at 20 kg ha-1 + its foliar spray (0.5%) at flower initiation and pod formation resulted in significantly higher grain yield (1043 kg ha-1), grain Zn concentration (44.3 mg zinc kg-1), grain protein content (26.5%) and net returns (646.9 US $ ha-1) followed by soil application of ZnSO4 (20 kg ha-1) + foliar application (0.5%) at flower initiation alone. Therefore, it can be concluded that soil application of ZnSO4 (20 kg ha-1) + its foliar spray (0.5%) at flower initiation and pod formation has ample scope in improving productivity and profitability of mungbean along with improved grain Zn concentration for ameliorating Zn malnutrition in the form of hidden hunger in the burgeoning population.
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Soil and foliar application are the most widely used methods for adding micronutrients to maize. High quality micronutrient fertilizers, however, are difficult to obtain in developing countries; micronutrient seed coatings are an attractive and practical alternative. We applied this approach to maize (Zea mays L.) to demonstrate the effects of boron (B), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn) sulfates on maize germination, vigor, seedling growth, seed yield and seed quality as well as on seed microelement concentration. Seed coating was tested on three representative Chinese soil types (sandy, purple and lime soils). Compared to untreated controls, coating maize seeds with micronutrients significantly increased the seed emergence rate, seedling height, leaf length, leaf width, leaf area, main root length, root number, above ground fresh biomass, above ground dry biomass, underground fresh biomass, underground dry biomass, ear thickness and yield in sandy, purple and lime soils. Coating maize seeds with micronutrients also significantly increased the yield and quality of maize seed compared to untreated controls including ear barren tip, ear length, ear thickness, grains/row, hundred seed weigh, and rows/ear. Also, B, Zn, Fe, Mn and Mo microelements accumulated in maize seed after coating the seed with micronutrients. Our findings indicate that micronutrient seed coating may improve nutrient uptake and production of maize hybrids.
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Tomato (Solanum lycopersicum) seedlings were exposed by foliar or root applications to Zn in different nanoscale and non-nanoscale forms (40 mg Zn/L) under hydroponic conditions for 15 days. Under foliar exposure, ZnO QDs significantly promoted tomato growth, while ZnO NPs and BPs had lower impacts. ZnO QDs increased fresh weight and plant height by 42.02 % and 21.10 % relative to the untreated controls, respectively. The ionic control (ZnSO4·7H2O, 176.6 mg/L) decreased fresh weight by 39.31 %. ZnO QDs also significantly increased the Chla/Chlb ratio, as well as carotenoids and protein content by 7.70 %, 8.90 % and 26.33 %, respectively, over the untreated controls, suggesting improvement in seedling photosynthetic performance. Antioxidant enzyme (POD, PPO and PAL) activities in ZnO QDs treated shoots were significantly decreased by 31.1 %, 17.8 % and 48.3 %, respectively, indicating no overt oxidative damage from exposure. Importantly, the translocation factor of Zn (TFZn) in the foliar exposure of the ZnO QDs treatment was 73.2 %, 97.1 % and 276.9 % greater than the NPs, BPs, and ionic controls, respectively. Overall, these findings clearly demonstrate that foliar spray of nanoscale nutrients at the appropriate concentration and size can significantly increase crop growth and be a sustainable approach to nano-enabled agriculture.
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During the last few decades, multiple agronomic innovations have been introduced to boost up the yield potential of agricultural crops. Among these innovations, use of conservation agriculture approaches, and use of resource conservation technologies, e.g. direct-seeded rice (Oryza sativa L.), zero-tillage wheat (Triticum aestivum L.), laser land levelling, permanent raised beds, have been widely adopted across globe, to reduce the production cost and improve the soil health, the farmer profitability and decrease the water losses. Crop diversification with legumes and allelopathic crops for improving soil health and reducing weed pressure is also gaining momentum in different cropping systems. Cereal–legume intercropping for improving soil health, push-pull technology for control of crop pests, combination of soil–water balance and crop-phenological models for efficient water use, use of controlled and slow-release fertilizer for efficient nutrient management, use of arbuscular mycorrhizal fungi and rhizobacteria to improve nutrient-use efficiency and use of seed-enhancement techniques for improving stand establishment and crop performance are the prime agronomic innovation which are being promoted at farmer field to enhance farmer yield and profitability.
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Zinc (Zn) is an essential micronutrient for plant growth and development, and anthocyanin is a secondary metabolite compound generally produced under stress conditions; both have benefits to human health. Rice is a staple food crop for most of the world’s population, and purple rice is well known as a natural source of Zn and anthocyanins, but their stability depends upon many factors. This review focuses on the opportunity to increase Zn and anthocyanin compounds in purple rice grains via Zn and nitrogen (N) management during cultivation. Variation in grain Zn concentration and anthocyanin compounds is found among purple rice varieties, thus presenting a challenge for breeding programs aiming at high grain Zn and anthocyanin contents. Genetic engineering has successfully achieved a high-efficiency vector system comprising two regulatory genes and six structural anthocyanin-related genes driven by endosperm-specific promoters to engineer purple endosperm rice that can provide new high-anthocyanin varieties. Grain Zn and anthocyanin concentrations in rice can also be affected by environmental factors during cultivation, e.g., light, temperature, soil salinity and nutrient (fertilizer) management. Applying N and Zn fertilizer is found to influence the physiological mechanisms of Zn absorption, uptake, transport and remobilization to promote grain Zn accumulation in rice, while N application can improve anthocyanin synthesis by promoting its biosynthesis pathway via the use of phenylalanine as a precursor. In summary, there is an opportunity to improve both grain Zn and anthocyanin in purple rice by appropriate management of Zn and N fertilizers during cultivation for specific varieties.
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Globally, many developing countries are facing silent epidemics of nutritional deficiencies in human beings and animals. The lack of diversity in diet, i.e., cereal-based crops deficient in mineral nutrients is an additional threat to nutritional quality. The present review accounts for the significance of biofortification as a process to enhance the productivity of crops and also an agricultural solution to address the issues of nutritional security. In this endeavor, different innovative and specific biofortification approaches have been discussed for nutrient enrichment of field crops including cereals, pulses, oilseeds and fodder crops. The agronomic approach increases the micronutrient density in crops with soil and foliar application of fertilizers including amendments. The biofortification through conventional breeding approach includes the selection of efficient genotypes, practicing crossing of plants with desirable nutritional traits without sacrificing agricultural and economic productivity. However, the transgenic/biotechnological approach involves the synthesis of transgenes for micronutrient re-translocation between tissues to enhance their bioavailability. Soil microorganisms enhance nutrient content in the rhizosphere through diverse mechanisms such as synthesis, mobilization, transformations and siderophore production which accumulate more minerals in plants. Different sources of micronutrients viz. mineral solutions, chelates and nanoparticles play a pivotal role in the process of biofortification as it regulates the absorption rates and mechanisms in plants. Apart from the quality parameters, biofortification also improved the crop yield to alleviate hidden hunger thus proving to be a sustainable and cost-effective approach. Thus, this review article conveys a message for researchers about the adequate potential of biofortification to increase crop productivity and nourish the crop with additional nutrient content to provide food security and nutritional quality to humans and livestock.
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Bu çalışmada, çinko (Zn) ile tohum ön uygulamasının koca fiğ (Vicia narbonensis L.) çeşitlerinde çimlenme ve fide gelişim parametrelerine etkilerinin belirlenmesi amaçlanmıştır. Araştırma; Siirt Üniversitesi, Ziraat Fakültesi, Tarla Bitkileri Laboratuvarı’nda, 25±1 oC kontrollü şartlar altında yürütülmüştür. Çalışmanın bitkisel materyalini Karakaya ve Halilbey koca fiğ çeşitleri oluşturmuştur. Laboratuvar çalışması, tesadüf parselleri deneme desenine göre 4 tekrarlamalı olarak petri kaplarında kurulmuştur. Araştırmada çinko sülfatın 0.5, 1.0, 1.5, 2.0 ve 2.5 mM konsantrasyonu ile hidro-priming uygulaması ve kontrol olarak priming yapılmayan grup araştırmanın konusunu teşkil etmiştir. Çalışmada; çimlenme oranı, ortalama çimlenme süresi, çimlenme üniformite katsayısı, çimlenme enerjisi, çimlenme indeksi, fide yaş ve kuru ağırlığı ve fide güç indeksi parametreleri incelenmiştir. Araştırma sonuçlarına göre, Zn priming uygulamasının çimlenme ve fide gelişim parametrelerini anlamlı derecede etkilediği saptanmıştır. Çalışmada Zn priming uygulamalarına göre; çimlenme oranı % 74.7-90.7, ortalama çimlenme süresi 2.00-2.65 gün, çimlenme üniformite katsayısı 28.56-46.15, çimlenme enerjisi 0.0-22.2, çimlenme indeksi 7.4-13.1, fide yaş ağırlığı 0.349-0.449 g, fide kuru ağırlığı 0.105-0.121 g ve fide güç indeksi 25.5-40.3 arasında değişim göstermiştir. Bu çalışmada, çinko sülfat priming uygulamasının, koca fiğ çeşitlerinin çimlenme ve fide gelişimleri üzerine etkili olabileceğini göstermiştir. Çalışmada ayrıca, priming uygulamalarının etkilerinin çeşide göre de farklılık gösterdiği görülmüştür. Araştırma sonucunda, koca fiğ tohumlarında çinko ile tohuma ön uygulamanın genel olarak çinkonun 2 mM dozunda en olumlu sonuçlar verdiği söylenebilir. Koca fiğ bitkisinde çimlenme ve fide gelişimi açısından; daha homojen bir gelişimin sağlanması, tohumların çimlenmesinin kolaylaşması ve hızlanması için tohumlara çinko sülfat uygulamasının kullanılması önerilmektedir.
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Nanoparticles (NPs) are increasingly used as agrochemical components through foliar spraying such as foliage fertilizers or pesticides. However, the understanding of the mechanisms of nanoparticle absorption and translocation from the leaf surface is limited. In this study, ZnO NPs (30 nm) labeled with fluorescein isothiocyanate (FITC) were foliar applied to wheat leaf tissues to investigate the process of attachment and absorption. Using laser confocal microscopy, we observed that FITC–ZnO NPs cross the leaf epidermis through the stomata and accumulate first in the apoplast, followed by subsequent transport to mesophyll cells. The Zn concentrations in wheat leaf apoplast and cytoplasm decreased by 33.2% and 8.3% with stomatal aperture diameter reduction, respectively; the apoplastic Zn concentration is influenced more by stomatal aperture than the cytoplasmic Zn level. Scanning electron microscopy with energy-dispersive X-ray analysis was used to map Zn in the wheat leaves and data suggest a different Zn distribution for ZnO NPs and ZnSO4. Zn ions in ZnO NP-treated samples are heterogeneously distributed in comparison with those in ZnSO4-treated samples. The results indicate that the main route to cross the wheat leaf epidermis for ZnO NPs is via the stomata; then these nanoparticles accumulate and release Zn ions in the apoplast, and the released Zn ions and ZnO NPs are absorbed by mesophyll cells. Our findings demonstrate how ZnO NPs cross the wheat leaf epidermis, distribute within mesophyll tissues, and enter into plant cells, and this information is useful for the development of sustainable nano-enabled platforms for nanoscale micronutrient delivery.
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Deficiency of micronutrients such as zinc (Zn) and iron (Fe) is a worldwide nutritional constraint in crop production particularly in growth, yield, and grain nutrient of crops, especially cereals such as wheat and rice in calcareous soils. On the other hand, Zn is an important nutrient for the growth and development of animals and humans and shortage in food causes severe damages economically due to malnutrition considerations. Micronutrient malnutrition in humans in developing countries is derived from deficiencies of these elements in staple food. Many approaches have been chosen to increase the Zn and Fe content in crops and ameliorate their malnutrition, including breeding, genetic engineering, and agronomic approaches. In this study, effects of agronomic biofortification components including different dose, proper stage of application, and effective method of micronutrient application are investigated on quantitative and qualitative yield of crops. The investigations of agronomy showed that micronutrient has an important role in the improvement of quantitative and qualitative crop yield. Hence, application of micronutrients such as Zn increased the grain yield due to its effect on the number of fertile spikelet per spike, number of grains per spike, and other agronomic traits. Also, this nutrient increased Zn and other micronutrient concentration in grain, grain protein, amino acid contents, and ascorbic acid content in grain but decreased phytic acid (PA) content and PA/Zn molar ratio in grain crops in most cases which increased bioavailability of micronutrients for human. In most cases, micronutrient application through foliar treatment performed better than other application methods. Studies indicated that application of micronutrients especially Zn and Fe led to increase in grain yield as well as positive aspects of seed quality and decrease in seeds’ negative qualities. Therefore, this approach (agronomic biofortification) can be used as appropriate short-term strategy, capable of improving quantitative and qualitative food security.
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Purpose: Chickpea is mostly grown in sandy loam soils having receding soil moisture and Zn deficiency which limits the chickpea productivity. Zn solubilizing plant growth promoting bacteria (PGPB) may improve the availability and uptake of Zn in these soils. Methods: This two-year field study was conducted to evaluate the interactive effects of pre-optimized Zn application methods and Zn solubilizing PGPB (i.e. endophyte Enterobacter sp. MN17) on the productivity and quality of desi chickpea during 2016-17 and 2017-18. Zn was delivered through osmopriming (0.001 M Zn solution), seed coating (5 mg Zn kg-1 seed), foliar application (0.025 M Zn solution), and soil application (10 kg Zn ha-1) with or without Zn solubilizing PGPB, while hydroprimed seeds were taken as control. Results: Zn application through either method improved the grain yield, economics, bioavailable Zn, and grain quality of desi chickpea. The maximum improvement in grain yield (43.7%) was recorded with Zn soil application followed by Zn seed coating (38.8%). The highest protein contents (22.8%), grain Zn concentration (45.8 µg g-1), bioavailable Zn contents (4.38 mg Zn day-1), and minimum phytate contents (12.0 mg g-1) were recorded by Zn soil application. The maximum mineral matter (3.89%) and fiber contents (4.81%) were recorded with Zn soil application + PGPB. The maximum agronomic efficiency (6409 kg kg-1), agro-physiological efficiency (160 kg kg-1), and apparent recovery efficiency (76.8%) were noted by Zn osmopriming + PGPB. However, the maximum physiological (289 kg kg-1) and utilization efficiency (10559 kg kg-1) were recorded with Zn osmopriming. Moreover, the highest economic returns ($ 1518.2 ha-1) and marginal net benefits ($ 571.5 ha-1) were recorded with Zn soil application + PGPB. Conclusions: To improve the productivity, profitability, and grain quality of desi chickpea Zn application through soil or seed coating in combination with plant growth promoting bacteria may be opted to maximize the productivity and profitability.
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Zinc (Zn) is an essential micronutrient for plants and animals. Unfortunately, deficiency of Zn in humans has increased on a global scale. The main reason of this micronutrient deficiency is dietary intakes of food with low Zn levels. Adoption of biofortification approaches would result in Zn enrichment of target tissue to a considerable extent. However, there is a basic need to understand Zn absorption mechanisms in plants prior to exploitation of such practical approaches. Zn absorption is a complex physiological trait which is mainly governed by Zn transporters and metal chelators of plant system. Plant growth stage, edaphic factors, season etc. also influence Zn efficiency of particular species. Molecular studies in Zn hyperaccumulators have already demonstrated the participation of specific Zn transporters, vacuolar sequestration and detoxification mechanisms in maintenance of Zn homeostasis. These have been described in detail in present review and provide opportunities for utilization in biofortification programmes. However, issues such as lesser bioavailability of Zn in target organ, uptake of toxic divalent cations (Cd, Ni, Pb, As etc.) along with Zn, sink activity and dilution in Zn concentration in response to sink number etc. in biofortified crops need further investigation. In order to design novel strategy in biofortification programmes, future researches should focus on physiological performance and yield penalties in concerned crop, metabolic load in term of organic acid production and crosstalk of Zn with other mineral nutrients under low and high Zn conditions.
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A field experiment was conducted during kharif and rabi seasons of 2002-2003 and 2003-2004 on a saline soils, to study the effect of various levels, methods of application and residual effect of Zn on yield, nutrient concentration and uptake of blackgram (Vigna mungo). Twelve treatments comprising of four ZnSO4 levels (0, 12.5, 25 and 50 kg ha -1) were distributed to the two crops of riceblackgram in a cropping system. The maximum grain and haulm yields of blackgram were recorded with treatment that received 25 kg ZnSO4 ha-1 to blackgram. The effect of all foliar treatments applied at different stages of crop proved to be at par with each other. The performance of the treatments was in the order: soil application > foliar treatments > residual fertility. The nutrient status of soil at the end of rice-blackgram cropping sequence indicated that the available N and Zn status of soil increased and that of K to decrease when compared with the initial soil status.
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Seed coating is among the most potentially beneficial treatments to enhance seedperformance, contributing to the improvement of crop stands due to its role in improvedseedling development. Thus, micronutrients such as zinc exhibit potential for use in seedcoatings. The objective of this research is to evaluate the effect of coating wheat seeds withzinc sulfate on traits that are related to seed quality during storage and nutrition efficiencyduring seedling growth. The levels of ZnSO4 used were 0, 1, 2, 3 and 4 mL kg-1 seed. After 0, 3and 6 months of storage, the germination percentage, mean root length, root dry mass, seedlingemergence, nutritional efficiency (absorption, transport and use) and zinc content in the seedswere evaluated. Seed coating with ZnSO4 increased seedling dry weight and zinc content inroots, which are the primary sink for this nutrient. Higher rates of ZnSO4 coating resulted inhigher absorption efficiency and a concomitant decrease in Zn transport and use efficiency.Thus, the application of appropriate doses of zinc to seeds increases the accumulation of thisnutrient, resulting in well-nourished plants that present improved initial development underadverse conditions.
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Estimation of zinc and its bioavailability in wheat grains is a prerequisite for an effective biofortification program. The selected 65 bread wheat varieties are representative of indigenous and foreign genetic pools being used for genotype development at the Wheat Research Institute, Faisalabad (Pakistan). The main objectives of the study were: (i) to determine the variation in phytate and zinc concentrations in whole grains; (ii) to estimate the bioavailable zinc in wheat grains by using trivariate model of zinc absorption and phytate to zinc molar ratios ([phytate]:[zinc]); and (iii) to examine the interrelationship of bioavailable zinc with year of variety release. Average zinc in grains of wheat varieties was 29 μg g–1 and ranged from 24 to 36 μg g–1. Phytate in grains ranged from 7.1 to 11.1 mg g–1 resulting in a variation in [phytate]:[zinc] of 24 to 41. The estimated bioavailable zinc in grains ranged from 1.52 to 2.15 mg zinc for 300 g of wheat flour, indicating that only 21 ± 3% of grain zinc was actually bioavailable. Year of variety release in Punjab (Pakistan) had significant negative correlations with total (r = –0.70, n = 46, P < 0.001) and estimated bioavailable (r = –0.65, n = 46, P < 0.001) zinc in wheat grains. This demands for an effective breeding program with optimized agronomic approaches to restore and improve the bioavailable zinc in grains of cultivated bread wheat varieties for Pakistan.
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The objective of this study was to evaluate the performance of seeds of two cultivars of lowland rice (Oryza sativa L.), coated with dolomitic limestone and aluminum silicate. It was used a completely randomized experimental design, with the treatments arranged in a 4 X 2 factorial scheme [4 treatments: dolomitic limestone; dolomitic limestone + aluminum silicate; aluminum silicate, at the dosages of 50 g/100 kg of seeds; and control (without the products) X 2 cultivars: IRGA424 and IRGA 422 CL], totaling eight treatments with four replications each. The variables analyzed were: fresh and dry weights of aerial biomass; plant height; leaf area at 10, 20, and 30 days after emergence (DAE). The physiological quality of seeds was also assessed using tests of: seed emergence; first count of germination; emergence speed index; and field emergence. It was concluded that the coating of rice seeds with dolomitic limestone and aluminum silicate does not affect seed germination and field seedling emergence. Aluminum silicate used via seed coating on cultivar IRGA 424 promoted greater leaf area, after 20 DAE. The dolomitic limestone and the aluminum silicate used via seed coating generated plants with larger dry biomass, after 20 DAE, for the cultivar IRGA 422 CL.
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An important goal of micronutrient biofortification is to enhance the amount of bioavailable zinc in the edible seed of cereals and more specifically in the endosperm. The picture is starting to emerge for how zinc is translocated from the soil through the mother plant to the developing seed. On this journey, zinc is transported from symplast to symplast via multiple apoplastic spaces. During each step, zinc is imported into a symplast before it is exported again. Cellular import and export of zinc requires passage through biological membranes, which makes membrane-bound transporters of zinc especially interesting as potential transport bottlenecks. Inside the cell, zinc can be imported into or exported out of organelles by other transporters. The function of several membrane proteins involved in the transport of zinc across the tonoplast, chloroplast or plasma membranes are currently known. These include members of the ZIP (ZRT-IRT-like Protein), and MTP (Metal Tolerance Protein) and heavy metal ATPase (HMA) families. An important player in the transport process is the ligand nicotianamine that binds zinc to increase its solubility in living cells and in this way buffers the intracellular zinc concentration.
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Field experiments were conducted to evaluate the effects of summer green manuring crops (SGMCs) and zinc (Zn) fertilization on soil biological properties, nutrient dynamics and productivity of Basmati rice, during summer–rainy (kharif, April–November) seasons of 2008 and 2009 at the research farm of the Indian Agricultural Research Institute, New Delhi. Among the SGMCs, Sesbania aculeata added the highest crop residue, i.e. 38.56 t ha−1 leading to recycling of 180.5, 22.6 and 267.8 kg N, P, K ha−1 (mean of 2 years). Incorporation of S. aculeata also led to a significant increase in the succeeding Basmati rice grain yield which was 2.38%, 4.14%, and 10.82% higher over cowpea, mungbean and summer fallow, respectively. Among the different sources, levels and methods of Zn application, application of 2.0% Zn-enriched urea (ZEU) as ZnSO4·H2O was found to be best with respect to total uptake of N, P, K and Zn by rice and also soil biological properties, especially enhanced alkaline phosphatase, dehydrogenase, fluorescein diacetate activities and microbial biomass C. Application of 2.0% ZEU as ZnSO4·H2O recorded the highest Basmati rice grain yield, i.e. 3.79 t ha−1 and the increase was registered to the tune of 12.78%, 2.43%, 3.26%, 5.71%, 7.05% and 5.27% over control (only N), 2.0% ZEU as ZnO, 5 kg Zn ha−1 as ZnSO4·H2O, 5 kg Zn ha−1 as ZnO, 0.5 kg Zn as ZnO slurry and 1.0 kg Zn through 0.2% foliar spray, respectively. Our results clearly indicated that incorporation of S. aculeata SGMC residue in conjunction with 2% ZEU as ZnSO4·H2O significantly enhanced soil microbial activities, which are vital for the nutrient turnover and long-term productivity of soil, leading to enhanced productivity of Basmati rice.
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Essential plant nutrients are mainly applied to soil and plant foliage for achieving maximum economic yields. Soil application method is more common and most effective for nutrients, which required in higher amounts. However, under certain circumstances, foliar fertilization is more economic and effective. Foliar symptoms, soil and plant tissue tests, and crop growth responses are principal nutrient disorder diagnostic techniques. Soil applications of fertilizers are mainly done on the basis of soil tests, whereas foliar nutrient applications are mainly done on the basis of visual foliar symptoms or plant tissue tests. Hence, correct diagnosis of nutrient deficiency is fundamental for successful foliar fertilization. In addition, there are some more requirements for successful foliar fertilization. Foliar fertilization requires higher leaf area index for absorbing applied nutrient solution in sufficient amount, it may be necessary to have more than one application depending on severity of nutrient deficiency. Nutrient concentration and day temperature should be optimal to avoid leaf burning and fertilizer source should be soluble in water to be more effective. Foliar fertilization of crops can complement soil fertilization. If foliar fertilization is mixed with postemergence herbicides, insecticides, or fungicides, the probability of yield response could be increased and cost of application can be reduced.
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Plants of two tomato cvs., ‘Blizzard’ and ‘Liberto’ were grown in sand culture in a glasshouse at Zn concentrations of 0.15 and 7.70 μmol l⁻¹ in the nutrient solution. Foliar treatments entailed applying zinc as either 0, 0.35 or 3.5 mmol l⁻¹ ZnSO4·7H2O to the tops of plants grown at low zinc (0.15 μmol l⁻¹) in nutrient solution twice a week during the course of the experiment. Plants treated with 0.15 μmol l⁻¹ Zn in the nutrient solution and high levels of zinc (3.5 mmol l⁻¹) applied as a foliar spray showed a significant decrease in the production of dry matter, chlorophyll and green fruit yield as compared with those grown both at 7.70 μmol l⁻¹ zinc in the nutrient solution and at 0.15 μmol l⁻¹ zinc in nutrient solution with 3.5 mmol l⁻¹ zinc applied as a foliar spray. There were differences between the cultivars but no consistent link between these differences and nutrient concentrations within the plant. Concentrations of K, Mg and Zn were lower in the leaves and fruit of both the cultivars in 0.15 μmol l⁻¹ zinc in the nutrient solution treatment as compared with both the 7.70 μmol l⁻¹ in the nutrient solution treatment and with supplementary foliar applications of zinc at 0.35 mmol l⁻¹. Potassium and Mg were also lower in the leaves and fruit of both the cultivars receiving foliar applications of zinc at 3.5 mmol l⁻¹.
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When grown on soils with low micronutrient availability due to either chemical or biological fixation, or spatial or temporal unavailability, micronutrient-efficient genotypes have a greater yield in comparison to inefficient ones, even when fertilized with smaller amounts of fertilizers or less frequently. This review summarizes published information on genotypic differences in Zn, Fe and Mn efficiency. Generally, micronutrient-efficient genotypes are capable of increasing available soil micronutrient pools through changing chemical and microbiological properties of the rhizosphere as well as by growing thinner and longer roots and having more efficient uptake and transport systems. For Zn-efficient genotypes, more efficient utilization of Zn in tissue also contributes to overall Zn efficiency. Understanding micronutrient efficiency mechanisms is important for designing suitable screening techniques for breeding micronutrient-efficient genotypes. Growing micronutrient-efficient genotypes contributes to environmentally-benign agriculture by lowering the input of chemicals and energy. These genotypes also offer a potential for producing grain for human consumption with higher concentration of Fe, Zn and Cu, the three micronutrients that about a third of the world population is deficient in.
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Micronutrients are vital for plant growth and human health. Soil and foliar applications are the most prevalent methods of micronutrient addition but the cost involved and difficulty in obtaining high quality micronutrient fertilizers are major concerns with these in developing countries. Micronutrient seed treatments, which include seed priming and seed coating, are an attractive and easy alternative. Here in this review, we discuss the potential of micronutrient seed treatments for improving crop growth and grain nutrient enrichment. Micronutrient application through seed treatments improves the stand establishment, advances phenological events, and increases yield and micronutrient grain contents in most cases. In some instances, seed treatments are not beneficial; however, the negative effects are rare. In most cases, micronutrient application through seed treatment performed better or similar to other application methods. Being an easy and cost effective method of micronutrient application, seed treatments offer an attractive option for resource-poor farmers.
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Soil deficiencies of zinc (Zn) and boron (B) limit crop production in Nepal. Improving the micronutrient status of plants would increase yield and increase micronutrient content of the seeds, leading to better nutrition of the progeny crop and to improved human micronutrient nutrition. The primary micronutrient problem in grain legumes is B deficiency, while in rice (Oryza sativa), Zn deficiency is more important, and wheat (Triticum aestivum) suffers from both deficiencies. A series of field experiments was carried out over two seasons to compare soil fertilization and micronutrient seed priming as methods of improving Zn and B nutrition of each crop. Micronutrient treatments were evaluated for their effect on grain yield and grain micronutrient content. Soil B fertilization increased B content of the grain of lentil (Lens culinaris), chickpea (Cicer arietinum), and wheat by a factor of two to five, while increasing the yield of chickpea only. Soil fertilization with Zn had no effect on yield of any crop, but resulted in a small increase in Zn in wheat grain. Sowing micronutrient-primed seeds had no effect on yield or micronutrient content of the progeny seeds in most cases. During the first season, the primed chickpea seeds failed to emerge at either site, causing complete yield loss, but this negative effect was not observed in the second season with similar priming treatments at nearby sites, and no effect of priming on yield was observed with any other crop in either season.
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Zinc (Zn) deficiency is prevalent worldwide and is a barrier to achieving yield goals in crops. It is also now recognized as a leading risk factor for disease in humans in developing countries. In general, soil application of 5–17kg of Zn ha−1year−1 as zinc sulphate (ZnSO4) or more is recommended. However, in developing rice growing countries of Asia, ZnSO4 of desired quality is not readily available and is also quite expensive, so the farmers generally fail to apply Zn, resulting in rice crop yield loss. Availability of Zn-coated urea guarantees not only the availability of quality Zn but also ensures its application. Field experiments were therefore conducted during the rice seasons of 2005 and 2006 at the Indian Agricultural Research Institute, New Delhi, to evaluate the relative efficiency of 0.5, 1.0, 1.5 and 2.0% Zn as ZnSO4- or zinc oxide (ZnO)-coated ureas for rice. Soil application of ZnSO4 was also compared in 2006. Rice grain and straw yields, Zn concentrations in grain and straw, and Zn uptake by rice increased with the level of Zn coating onto urea. Crop response was the highest with 2.0% ZnSO4-coated urea, and higher than with the same rate of ZnO-coated urea, possibly related to the higher water solubility of Zn in ZnSO4. Crop response with ZnSO4-coated urea was also higher than with the same rate of ZnSO4 and urea applied separately to the soil. However, apparent recovery data suggest that 1.0% coating with ZnSO4 may be a better choice from the point of view of the utilization of applied Zn. Increased Zn concentrations in rice grain due to application of Zn-coated urea is important from the point of view of Zn nutrition of humans, since rice is the staple food in developing countries of Asia. Also, increased Zn concentrations in rice straw is of importance as regards cattle nutrition since in developing countries of Asia rice straw is the major feed for farm cattle.
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The importance of micronutrients in health and nutrition is undisputable, and among them, zinc is an essential element whose significance to health is increasingly appreciated and whose deficiency may play an important role in the appearance of diseases. Zinc is one of the most important trace elements in the organism, with three major biological roles, as catalyst, structural, and regulatory ion. Zinc-binding motifs are found in many proteins encoded by the human genome physiologically, and free zinc is mainly regulated at the single-cell level. Zinc has critical effect in homeostasis, in immune function, in oxidative stress, in apoptosis, and in aging, and significant disorders of great public health interest are associated with zinc deficiency. In many chronic diseases, including atherosclerosis, several malignancies, neurological disorders, autoimmune diseases, aging, age-related degenerative diseases, and Wilson's disease, the concurrent zinc deficiency may complicate the clinical features, affect adversely immunological status, increase oxidative stress, and lead to the generation of inflammatory cytokines. In these diseases, oxidative stress and chronic inflammation may play important causative roles. It is therefore important that status of zinc is assessed in any case and zinc deficiency is corrected, since the unique properties of zinc may have significant therapeutic benefits in these diseases. In the present paper, we review the zinc as a multipurpose trace element, its biological role in homeostasis, proliferation and apoptosis and its role in immunity and in chronic diseases, such as cancer, diabetes, depression, Wilson's disease, Alzheimer's disease, and other age-related diseases.
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Arabidopsis thaliana has eight genes encoding members of the type 1(B) heavy metal-transporting subfamily of the P-type ATPases. Three of these transporters, HMA2, HMA3, and HMA4, are closely related to each other and are most similar in sequence to the divalent heavy metal cation transporters of prokaryotes. To determine the function of these transporters in metal homeostasis, we have identified and characterized mutants affected in each. Whereas the individual mutants exhibited no apparent phenotype, hma2 hma4 double mutants had a nutritional deficiency phenotype that could be compensated for by increasing the level of Zn, but not Cu or Co, in the growth medium. Levels of Zn, but not other essential elements, in the shoot tissues of a hma2 hma4 double mutant and, to a lesser extent, of a hma4 single mutant were decreased compared with the wild type. Together, these observations indicate a primary role for HMA2 and HMA4 in essential Zn homeostasis. HMA2promoter- and HMA4promoter-reporter gene constructs provide evidence that HMA2 and HMA4 expression is predominantly in the vascular tissues of roots, stems, and leaves. In addition, expression of the genes in developing anthers was confirmed by RT-PCR and was consistent with a male-sterile phenotype in the double mutant. HMA2 appears to be localized to the plasma membrane, as indicated by protein gel blot analysis of membrane fractions using isoform-specific antibodies and by the visualization of an HMA2-green fluorescent protein fusion by confocal microscopy. These observations are consistent with a role for HMA2 and HMA4 in Zn translocation. hma2 and hma4 mutations both conferred increased sensitivity to Cd in a phytochelatin-deficient mutant background, suggesting that they may also influence Cd detoxification.
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The role of zinc (Zn) in reproduction of lentil (Lens culinaris Medik. cv. DPL 15) and the extent to which the Zn requirement for reproduction can be met through supplementation of Zn at the time of initiation of the reproductive phase have been investigated. Low supply (0.1micromol/L) of Zn reduced the size of anthers, the pollen producing capacity and the size and viability of the pollen grains. Scanning electron microscopy (SEM) of pollen grains of Zn deficient plants showed enhanced thickening of exine and wide and raised muri. In vitro germination of pollen grains was reduced by >50% and growth of pollen tubes was retarded. Unlike Zn sufficient plants, the cuticle around the stigmatic papillae of Zn deficient plants remained intact, preventing the interaction between pollen grains and stigmatic exudates that provides the polarity for the growth of pollen tubes through the stylar tract. Zn deficiency increased the activity of acid phosphatase and peroxidase in extracts of pollen grains. Histochemical localisation on the stigmatic surface and native PAGE of the enzyme extracts of pollen grain and stigma exudates showed enhanced expression of acid phosphatase and peroxidase and suppressed expression of esterase in response to Zn deficiency. Zn deficiency reduced the setting of seeds and also their viability. The effect on seed setting was more marked than on in vitro germination of pollen grains, suggesting that the latter was not the exclusive cause of inhibition of fertility. Possibly, loss of fertility was also caused by impairment in pollen-pistil interaction conducive to pollen tube growth and fertilisation. Impairment in pollen structure and function and seed setting was observed even when plants were deprived of Zn at the time of flowering, but to a lesser extent than in plants maintained with low Zn supply from the beginning. Increasing the Zn supply from deficient to sufficient at the initiation of flowering decreased the severity of Zn deficiency effects on pollen and stigma morphology, pollen fertility and seed yield. In conclusion, structural and functional changes induced in pollen grains and stigma of Zn deficient plants and associated decrease in seed setting of lentil indicate a critical requirement of Zn for pollen function and fertilisation that can be partially met by supplementing Zn at the onset of the reproductive phase.
Book
An understanding of the mineral nutrition of plants is of fundamental importance in both basic and applied plant sciences. The Second Edition of this book retains the aim of the first in presenting the principles of mineral nutrition in the light of current advances. This volume retains the structure of the first edition, being divided into two parts: Nutritional Physiology and Soil-Plant Relationships. In Part I, more emphasis has been placed on root-shoot interactions, stress physiology, water relations, and functions of micronutrients. In view of the worldwide increasing interest in plant-soil interactions, Part II has been considerably altered and extended, particularly on the effects of external and interal factors on root growth and chapter 15 on the root-soil interface. The second edition will be invaluable to both advanced students and researchers.
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Effects of heavy metals on soil fungi populations and soil fertility incidental to it were studied under laboratory conditions. Metal-amended antroposol type soil samples were incubated for a month at 17°C under natural light regime. Copper, zinc and lead were chosen as the most common industrial pollutants. Each metal was applied either of sulfate, chloride or acetate salt (at concentration varying from 0.4 to 16.14 g kg-1 soil); control - soil without metal amendment. Fungal populations (dilution plate method) were investigated and soil phytotoxicity test was performed. Elevated Cu, Zn and Pb concentrations in the soil infl uenced fungus community structure. Some species (Absidia glauca, Acremonium kiliense, Aspergillus fumigatus, and Alternaria alternata) detected in the control soil community were eliminated, while the abundance of the other species increased. Paecillomyces genus dominated in the soil amended with either of Cu or Zn. P. farinosus, P. fumosoroseum and fungal species from the Clonostachys, Penicillium and Lecanicillium genera were Znresistant. P. lilacinus and plant pathogenic fungi, A. alternata, Fusarium oxysporum, F. solani and Phoma lingam were very abundant in soil amended with Cu salts, followed by some saprotrophic fungi such as Cunninghamella echinulata and Mucor hiemalis f. hiemalis. An overall change in the plant (cress, Lepidum sativum; wheat, Ticicum aestivum; lupine, Lupinus polyphyllus, and sunfl ower, Heliannthus annus) seed viability was observed in comparison with control. Most deleterious effects on the seed germination were observed in case of zinc, medium - in case of copper, and the least - in case of lead. Zinc salts at used concentrations were unfavorable to both fungus populations and consequently to the seed viability.
Article
The paper presents the results of research of negative effects of zinc (Zn) on seed germination of wheat (Triticum aestivum L.). Besides the impact on the percentage of germination, the toxic effect on some morphometric characteristics was followed, too. Ripe seeds of wheat were exposed in standard laboratory conditions to the influence of zinc, in form of zinc chloride (ZnCl2), at different values of concentration. For each value of concentration it was determined the percentage of germinationed seeds, as well as the length of root and shoot. It as found the value of the concentration of ZnCl2, which inhibited completely germination of wheat. The mean values of the length of root and shoot for each concentration were compared with values obtained for the control group of seeds, which were not treated with ZnCl2. In addition to causing of inhibition of seed germination, the presence of zinc in the medium affects disorder of the physiological—biochemical processes during the growth and development of vegetative organs that it indicates the difference in the length of the root and shoot of treated seeds in relation to the control group of untreated seeds.
Article
The ecotoxicological effects of Zn2+ on germination and early seedling growth of six pulses were investigated. Seeds of these plants were exposed to seven different concentrations of Zn (0, 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 mM). The results indicated that root growth and shoot elongation of six pulse plants were more sensitive than seed germination and dry weight for measurement of the toxic of Zn2+ pollutions. Different species show different levels of tolerance to Zn2+ pollution. Vigna radiate and Lathyrus odoratus are the most sensitive to Zn2+, their germination percentage, root growth, shoot elongation and dry weight were significantly lower than other tested species, by contrast, Glycine max and Dumasia villosa are the most resist species, their germination and seedling growth almost were not influenced by Zn2+ pollution significantly comparing the control. There were significantly negatively correlations between seedling growth and increasing concentration of Zn2+ for Glycine max, Lathyrus odoratus and Dumasia villosa. The significantly negative correlations between germination and increasing concentration of Zn2+ were show for Lathyrus odoratus.
Article
Seed coatings containing phosphorus (P) can be an effective way of promoting early seedling growth in P-deficient soil, but there is insufficient information available on the P sources and rates which are both safe to germinating seeds and effective in supplying P. A growth chamber experiment was undertaken to study the effect on the emergence and early growth of phalaris (Phalaris aquatica L.) and lucerne (Medicago sativa L.) of seed coatings containing one of three P sources (mono-[MCP], di-[DCP], or tricalcium phosphate [TCP]) at three rates (0.625, 1.25 or 2.5 mg P seed-1). The emergence of lucerne was markedly delayed (as measured by fitted Mitscherlich functions) by increasing rates of MCP, whilst that of phalaris was only slightly delayed. DCP and TCP had only slight effects on the emergence of both species. Leaf number (at 27 days after sowing [d.a.s.]), dry matter yield and P content of shoots of both species (at 35 d.a.s.) were increased by all P sources. With phalaris, MCP was approximately four times as effective per unit of P as DCP, which in turn was approximately four times as effective as TCP, whereas, with lucerne, MCP was twice as effective as DCP, which in turn was twice as effective as TCP. The results show that whilst emergence was most affected by soluble P sources at high rates, these same sources were most effective in promoting early P uptake per unit of P applied.
Article
Cereal grain yield response to KCI fertilization has been reported on high K-testing soils in the Northern Plains. Other field studies have demonstrated that wheat (Triticum aestivum L.) yield increases to CI fertilization occurred where disease incidence was high. Therefore, field experiments on high K-testing soils were conducted over a 3-yr period to determine the responsiveness of spring wheat, barley (Hordeum vulgare L.), and oats (Avena sutiva L.) to KCI fertilization and to determine whether responses were due to K or to Cl. Experiments were conducted on soils representing Typic Argiustolls, Pachic Udic and Udic Haploborolls, and Pachic and Udic Haplustolls in eastern South Dakota. Spring wheat, barley, and oats showed grain yield increases (0.10 probability level) at four out of six, three out of six, and zero out of five sites, respectively, on soils that tested very high in ammonium acetate-extractable K. Wheat grain yield increases varied form 0.2 to 0.5 Mg ha⁻¹. Comparison of KCI, KNO3, and CaC12 treatments, soil analysis, and plant analysis all indicated that the yield increases on very high K-testing soils were due to the CI in the KCI and not due to the K. Six additional wheat experiments were conducted to determine the influence of starter K and CI (applied with seed) on grain yield; however, no yield increases to CI were detected in these studies. Both KCI and KNO3 at a 20 kg K ha⁻¹ rate significantly decreased yield at one of six sites. Other experiments showed that if sufficient CI was present in the soil or broadcast applied, no additional benefit to seed placed CI occurred. Generally, broadcast and seed placed KCI appeared equally effective. However, rates required for maximum yield at several sites were too high to be placed in direct seed contact with drill application due to potentially adverse salt effects. Grain yield increases were large enough to make KCI fertilization of these soils very economical, provided responsive sites could be predicted. Please view the pdf by using the Full Text (PDF) link under 'View' to the left. Copyright © . .
Article
Research on the effects of N and B applications on soybean [Glycine max (L.) Merr.] yield is limited. Experiments were conducted to determine the effect of (i) application rate and reproductive stage timing of N or B on soybean seed yield and (ii) cultivar, row spacing, or planting date on the response of soybean to R3-stage N and B applications. Nitrogen was applied to the soil at 0, 14, 28, 56, 84, 112, or 168 kg ha -1, or B was applied to the foliage at 0, 0.14, 0.28, or 0.56 kg ha -1 to either R3- or R5-stage soybean in the rate and timing experiments. Treatments for the cultivar, row-spacing, and planting-date experiments included 0 + 0, 56 + 0, 0 + 0.28, and 56 + 0.28 kg ha -1 N + B, respectively. In yield environments ranging from 2400 to 5300 kg ha -1, application of N or B did not increase seed yield at any rate or application stage, nor did cultivar, row spacing, or planting date alter this lack of response. Analysis of leaf tissue taken at the R2 soybean development stage and before nutrient application indicated that N and B concentrations were above the minimum level required by soybean for maximum yields not limited by N or B. Lack of response to supplemental N or B suggested that N supplied via fixation and soil organic matter mineralization and native levels of B in soils are adequate for high yields in the Mid-Atlantic Coastal Plain soybean production region.
Article
Natural inputs of chlorine (Cl) to soils come mainly from rainwater, sea spray, dust and air pollution. In addition, human practices, such as irrigation and fertilization, contribute significantly to Cl deposition. In the soil solution, Cl occurs predominantly as the chloride anion (Cl−). The Cl−anion does not form complexes readily, and shows little affinity (or specificity) in its adsorption to soil components. Thus, Cl−movement within the soil is largely determined by water flows. Chlorine is an essential micronutrient for higher plants. It is present mainly as Cl−. Chloride is a major osmotically active solute in the vacuole and is involved in both turgor- and osmoregulation. In the cytoplasm it may regulate the activities of key enzymes. In addition, Cl−also acts as a counter anion, and Cl−fluxes are implicated in the stabilization of membrane potential, regulation of intracellular pH gradients and electrical excitability. Chloride enters plants through the roots, and there is some concern over the uptake of the long-lived radionuclide36Cl, which enters into the food chain through plants. Chloride is thought to traverse the root by a symplastic pathway, and Cl−fluxes across the plasma membrane and tonoplast of root cells have been estimated. These fluxes are regulated by the Cl−content of the root. Chloride is mobile within the plant. The Cl−concentrations of xylem and phloem saps have been determined and Cl−fluxes through the xylem and phloem have been modelled. Measurements of transmembrane voltages and Cl−activities in cellular compartments suggest (1) that active Cl−transport across the plasma membrane dominates Cl−influx to root cells at low Cl−concentrations in the soil solution and that passive Cl−influx to root cells occurs under more saline conditions, and (2) that both active and passive Cl−transport occurs at the tonoplast. Electrophysiological studies have demonstrated the presence of an electrogenic Cl−/2H+symporter in the plasma membrane of root-hair cells and Cl−channels mediating either Cl−influx or Cl−efflux across the plasma membrane. Similarly, there is both biochemical and electrophysiological evidence that Cl−channels mediate Cl−fluxes in either direction across the tonoplast and that a Cl−/nH+antiport mediates Cl−influx to the vacuole. This article reviews the availability of Cl−in the soil, the roles and distribution of Cl−within the plant, the magnitude of Cl−fluxes across membranes and between tissues, the mechanisms of Cl−transport across membranes and the electrical characteristics and molecular biology of Cl−channels. Copyright 2001 Annals of Botany Company