Foliar Zinc Research Articles

Zinc Biofortification of Mungbean Cultivars through Root and Foliar Zinc Fertilization

Zinc Biofortification of Mungbean Cultivars through Root and Foliar Zinc Fertilization

Zinc fortification and legume incorporation in forage based cropping systems: Implications for yield and nutrient dynamics

Aim: To evaluate the synergistic effects of legume intercropping and zinc fortification on forage yield, and plant and soil nutrient dynamics. Methodology: The experiment was laid out in a Factorial Randomized Block Design. Treatment combinations included five cropping systems, i.e., sole maize, sole cowpea, sole soybean, maize + cowpea (2:1), maize + soybean (2:1) and three zinc levels; Zn0= control or no zinc application, Zn1 = 20 kg ZnSO4 ha-1 (basal soil application) and Zn2 = 20 kg ZnSO4 ha-1 (basal soil application) + 0.5% ZnSO4 sprayed twice (30 DAS and 50 DAS). Results: Sole maize recorded highest dry matter (11938 kg ha-1) yield. Soil + foliar zinc application (Zn2) recorded an increase of 37.93 % increase in dry matter yield over control (Zn0). Maize + legumes recorded higher nitrogen uptake. There was an overall increase (122.34%) in zinc uptake from Zn0 to Zn2. Soil + foliar applied Zn increased ZnUE by 27.60 % (619.14 kg) over soil applied Zn (485.19 kg). Zn application increased Zn values of soil to 0.50 ppm with soil application and 0.56 ppm with soil + foliar application from the initial value of 0.36 ppm. Interpretation: Intercropping of legumes and application of 20 kg ZnSO4 as basal soil application plus two foliar applications of 0.5% ZnSO4 at 30 and 50 days after sowing significantly increased forage yield, nutrient uptake and enhanced soil zinc levels. Key words: Cropping systems, Intercropping, Legumes, Nutrient dynamics, Yield, Zn fortification

Impact of Zinc Application on Growth, Yield, and Quality of African Marigold in Semi-Arid Conditions

Marigold is a widely cultivated, hardy flower crop known for its adaptability. Among the various intercultural practices in marigold cultivation, foliar application of zinc plays a critical role in enhancing yield and quality, however, standardization of this practice is necessary to optimize commercial production. Hence, the investigation aimed to standardize foliar zinc application for improving productivity in African marigold (Pusa Narangi Gainda) at Rajasthan Agricultural Research Institute, Jaipur, during 2020-21, and 2021-22. Two concentrations of zinc sulphate (ZnSO₄), Z1 (0.2%), and Z2 (0.5%), were applied at 35 and 65 days after transplanting (DAT) in a factorial randomized block design with three replications. Results indicated that Z1 (ZnSO₄ 0.2%) was most effective in increasing plant height, and promoting early bud initiation, and flower opening, while Z2 (ZnSO₄ 0.5%) significantly enhanced plant spread, primary branching, leaf dimensions, plant biomass, root-to-shoot ratio, flower diameter, and yield parameters such as flower mass and number. Z2 also improved quality traits like chlorophyll and xanthophyll content. Statistical analysis revealed significant differences among treatments, suggesting that the application of ZnSO₄ at 0.5% may be recommended for optimizing growth, yield, and quality in commercial marigold cultivation, thereby enhancing productivity and profitability.

Variation of grain zinc, phytate concentration and phytate : Zn molar ratio in unpolished and polished rice affected by foliar zinc application among Thai rice varieties

ABSTRACT This study evaluated the variation in grain yield and Zn concentration in rice after foliar application of Zn and the impact on its phytate : Zn molar ratio among 21 rice varieties. Rice varieties were grown under field conditions using a randomized complete block design with four replications over two cropping years in 2020 and 2021 during the rainy season. Foliar Zn application varied grain yield from −26.0 to 13.6% in 2020 and −14.7 to 30.4% in 2021 compared with non-foliar Zn. Grain Zn was varied from 0.5 to 31.1% in 2020 and from −5.9 to 47.8% in 2021 in unpolished rice and from 9.4 to 47.0% in 2020 and from 8.2 to 163.0% in 2021 in polished rice. The phytate : Zn molar ratio was decreased when foliar Zn was applied to the unpolished and polished rice, with a lower ratio in the polished rice. The phytate : Zn molar ratio decreased exponentially with increasing grain Zn concentration in the unpolished rice, while decreasing linearly with increasing grain Zn concentration in the polished rice. The results of this study suggest that foliar Zn application is a promising way to improve the grain Zn concentration and decrease the phytate : Zn molar ratio, thus being beneficial for human diets, but the effects of rice variety, cropping season, and the polishing process should be considered.

Interventional Effect of Zinc Oxide Nanoparticles with Zea mays L. Plants When Compensating Irrigation Using Saline Water.

High salinity reduces agriculture production and quality, negatively affecting the global economy. Zinc oxide nanoparticles (ZnO-NPs) enhance plant metabolism and abiotic stress tolerance. This study investigated the effects of 2 g/L foliar Zinc oxide NPs on Zea mays L. plants to ameliorate 150 mM NaCl-induced salt stress. After precipitation, ZnO-NPs were examined by UV-visible spectroscopy, transmission electron microscopy, scanning transmission electron microscopy, energy dispersive X-ray, and particle size distribution. This study examined plant height, stem diameter (width), area of leaves, chlorophyll levels, hydrolyzable sugars, free amino acids, protein, proline, hydrogen peroxide, and malondialdehyde. Gas chromatographic analysis quantified long-chain fatty acids, and following harvest, leaves, stalks, cobs, seeds, and seeds per row were weighed. The leaves' acid and neutral detergent fibers were measured along with the seeds' starch, fat, and protein. Plant growth and chlorophyll concentration decreased under salt stress. All treatments showed significant changes in maize plant growth and development after applying zinc oxide NPs. ZnO-NPs increased chlorophyll and lowered stress. ZnO-NPs enhanced the ability of maize plants to withstand the adverse conditions of saline soils or low-quality irrigation water. This field study investigated the effect of zinc oxide nanoparticles on maize plant leaves when saline water is utilized for growth season water. This study also examined how this foliar treatment affected plant biochemistry, morphology, fatty acid synthesis, and crop production when NaCl is present and when it is not.

Influence of Foliar Zinc Application on Cadmium and Zinc Bioaccessibility in Brassica chinensis L.: In Vitro Digestion and Chemical Sequential Extraction.

Foliar zinc (Zn) application can affect the accumulation and bioaccessibility of cadmium (Cd) and Zn in crops. However, the mechanisms by which foliar Zn application influences Cd and Zn bioaccessibility remain elusive. This study examined the effects of spraying ZnSO4 and ZnNa2EDTA on bioaccessibility and chemical forms of Cd and Zn in pakchoi (Brassica chinensis L.) shoots and evaluated human health risks via pakchoi consumption. Spraying ZnSO4 reduced the concentrations of ethanol-extractable (Fethanol) and deionized water-extractable (Fd-H2O) Cd, as well as the corresponding bioaccessible Cd concentrations (20.3-66.4%) and attendant health risks of Cd, whereas spraying high-dose ZnNa2EDTA significantly increased the concentrations of both Cd forms and bioaccessible Cd. Spraying ZnSO4 and high-dose ZnNa2EDTA significantly increased the concentrations of Zn in Fethanol and Fd-H2O and the corresponding bioaccessible Zn concentrations (0.8-8.3-fold). Fethanol and Fd-H2O were the primary sources of bioaccessible Cd and Zn, contributing more than 59% of the bioaccessible Cd and Zn. These results indicate that foliar Zn application can affect Cd and Zn bioaccessibility in pakchoi mainly by modulating Cd and Zn in Fethanol and Fd-H2O. These findings provide scientific support for the development of more efficient measures to produce safe and high-quality leafy vegetables from Cd-polluted soils.

Agronomic Effectiveness of Zinc Sources as Micronutrient Fertilizers: A Comprehensive Review’

Zinc naturally occurs in the earth's crust as part of rocks and ore minerals. The average concentration of zinc in the lithosphere is 80 mg kg-1. While zinc is relatively immobile in soil, it is moderately mobile in plants. As a vital micronutrient for both humans and animals, zinc plays an essential role in plants as a catalytic, structural and regulatory cofactor for many enzyme reactions. It is necessary for the metabolism of carbohydrates, protein synthesis, the biosynthesis of growth hormones (particularly indoleacetic acid) and the maintenance of cell membrane integrity. Zinc deficiency is a widespread problem affecting both plants and humans in many regions of the world. To address this issue and improve plant zinc nutrition and yields, both soil and foliar zinc fertilizers have been applied. The agronomic effectiveness of Zn fertilizers has been related to the management factors such as placement, source type, seed treatment, foliar spray and biofortification that can affect the effectiveness of Zn fertilizers.

Soil and Foliar Zinc Biofortification of Triticale (x Triticosecale) under Mediterranean Conditions: Effects on Forage Yield and Quality.

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

Zinc biofortification of wheat through fertilizer and genotype management

This study investigated the responses of two wheat varieties, Alvand (Zn-inefficient) and Pishtaz (Zn-efficient), to various zinc (Zn) fertilization methods to determine optimal strategies for enhancing wheat growth and grain quality. The primary aim of this research was to evaluate the effects of various Zn fertilization strategies, including foliar applications of Zn sulfate and Zn-EDTA with and without urea, as well as synthetic Zn amino acid complexes, along with soil applications of Zn sulfate, on the yield and nutritional quality of grains in these two contrasting wheat varieties. The results revealed that wheat varieties responded differently to Zn treatments. While Alvand showed a promising trend of elevated grain yield with foliar zinc sulfate application, Pishtaz exhibited a stronger response to foliar treatments like Zn-Met and Zn-EDTA + urea. Yield components as 1000-grain weight and spike weight, were significantly influenced by Zn fertilization. Foliar application of zinc sulfate + urea enhanced 1000-grain weight in Alvand, whereas Zn-EDTA + urea substantially increased spike weight in Pishtaz. Soil application of zinc sulfate was found to be as an effective method to enhance grain Zn content. Furthermore, the Zn concentrations in flour, straw, bran, and roots elucidated the complex patterns of Zn distribution among various plant tissues. Soil applications were particularly effective in increasing Zn levels in flour and bran, while foliar treatments influenced Zn content in straw and roots. Overall, this research highlights the importance of Zn fertilization strategies for different wheat varieties biofortification. These findings can provide practical implications for sustainable wheat production, addressing Zn deficiency challenges, and advancing food security worldwide. Further exploration into the underlying mechanisms of these responses is encouraged to refine Zn management practices for wheat cultivation.

Impact of integrated nutrient management and foliar zinc supplementation on rice (Oryza sativa L.) nutrient uptake and yield in the Cauvery Delta Zone

In 2023, rice production reached 523.9 million tons, making it the fourth most produced crop globally. Accounting for 14% of global fertilizer use, the demand for rice continues to increase. However, the unbalanced application of NPK fertilizers poses significant environmental risks. An integrated nutrient management approach, combining organic and inorganic sources, offers a cost-effective solution to meet crop nutritional needs while enhancing soil health. Therefore, a field experiment was conducted in Experimental Farm of Annamalai University during kuruvai (June-September) 2023 to evaluate the effect of different levels of inorganic fertilizers with different sources of organic manures along with foliar zinc sulphate on the yield and yield components in lowland rice. The experiment was laid out in randomized block design with nine treatments. These treatments included different sources of organic manures viz., farm yard manure, vermicompost, press mud and poultry manure and foliar application of zinc sulphate. The results revealed that combining 75% nitrogen through urea and 25% nitrogen from vermicompost and 100 % P and K along with foliar application of zinc sulphate (0.5%) at 25 and 50 days after transplanting (DAT) significantly improved all nutrient uptake of nitrogen, phosphorous and potassium and also yield parameters viz., number of productive tillers m-2, number of filled grains/panicle, grain yield, straw yield and harvest index of rice.

Economic Aspects of Zinc Oxide Fertilization in Yam (Dioscorea alata L.) in a Semi-Arid Region of Brazil

The management and improvement of yam productivity are associated with a good supply of essential nutrients for the growth and development of the crop that has economic viability. This research aimed to evaluate the economic feasibility of foliar fertilization with Zintrac® in two yam agricultural seasons (2022/2023 and 2023/2024). Therefore, two experiments were conducted at the Rafael Fernandes Experimental Farm, Mossoró, RN, Brazil. The experimental design was in a Latin square design with five treatments of doses of Zintrac® (0, 1, 2, 3, and 4 L ha−1) and five replications. Among the production costs of yams, labor and seed acquisition were the most significant. The highest profitability index was achieved with the dose of 1L Zintrac® ha−1 in the first season and second season, which corresponded to 78.97 and 57.86%. For the first season, increments were observed in all treatments that received zinc doses with increases of 48.70, 31.22, 14.30, and 15.93% for 1, 2, 3, and 4 L of Zintrac® ha−1 compared to the dose of 0 L ha−1. On the other hand, in the second season, there was an increase only in the dose of 1 L ha−1 of Zintrac®, which corresponded to 51.3% in the net yield (ha−1) of the dose of 0 L ha−1. Therefore, foliar zinc oxide fertilization was economically viable for the yam crop, obtaining higher economic indices at the dose of 1 L ha−1. The highest cost for growing yams is using a dose of 4 L ha−1 of Zintrac®, totaling USD 6977.59 (first season) and USD 6868.33 (second season)

Effect of Nitrogen, Zinc and Iron Fertilization on the Economic Yield of Wheat (Triticum aestivum. L)

The experiment was carried out entitled “Effect of nitrogen fertilizer and Ferti-fortification through zinc and iron on yield and economics of wheat (Triticum aestivum)” at the Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, (U.P.) during rabi season of 2021-22 and 2022-23. The soil of the experimental area was sandy clay loam with low organic matter, available nitrogen, medium in available phosphorus, potassium, zinc, iron and slightly alkaline in reaction. The result of the experiment revealed that the maximum grain yield (52.83 q ha-1 and 51.44 q ha-1), straw yield (66.06 q ha-1 and 65.40 q ha-1), net returns (₹ 106,008 ha-1 and ₹ 112,155 ha-1) and B:C ratio (3.27 & 3.26) was recorded with recommended nitrogen (150 kg N ha-1) + foliar zinc (0.5%) + foliar iron (0.5 %) treatments during 2021-22 and 2022-23, respectively.

Impacts of cobalt and zinc on improving peanuts nutrient uptake, yield and irrigation water use efficiency under different irrigation levels

The knowledge of proper fertigation across various irrigation levels is necessary for maximizing peanut yield and irrigation use efficiency in arid areas, and it also can effectively alleviate the risk of nutrient deficiency induced by water stress. This study evaluated the effectiveness of cobalt combined with two zinc application methods on peanut nutrient uptake, yield, and irrigation water use efficiency across varying irrigation levels. A split-split plot experiment was carried out in 2021 and 2022. Three peanut gross water requirement (GWR) levels (100%, 80%, and 60%) were designated for main plots. Subplots featured plants treated with either 0 or 7.5 mg L−1 of cobalt. The sub-sub plots assessed chelated zinc effects at rates of 0 and 2 g L−1 via foliar and soil applications. In comparison to the control (100% GWR), nutrient uptake decreased, with sodium being the exception, and there was an increase in soil pH at 60% GWR. The results showed also significant reductions in yield and water use by approximately 60.3% and 38.1%, respectively. At this irrigation level, applying zinc via soil, either alone or combined with cobalt, led to significant yield increases of 89.7% and 191.3% relative to the control. Also, it’s crucial to note that cobalt application negatively affected iron and copper at 60% GWR, but this impact was lessened with soil-applied zinc. Hence, under a similar circumstance, treating stressed peanut plants with additional foliar applications of iron + copper and applying zinc via soil, could enhance nutrient uptake and improve yield. On the other hand, at 80% GWR, a combination of foliar-applied zinc and cobalt, had a tremendous impact on the absorption of (nitrogen, phosphorus, magnesium, and zinc), resulting in enhanced agronomic traits and decreased water losses. Additionally, at this irrigation level, foliar zinc application alone yielded a 32.4% increase compared to the 80% GWR control. When combined with cobalt, there was a 70.0% surge in water use. Based on this knowledge, the study suggests using 80% GWR and treating peanut plants with a combination of foliar-applied zinc and cobalt. This strategy aids plants in countering the adverse effects of water stress, ultimately leading to enhanced yield and irrigation water use efficiency.

Stable Isotope Analyses Reveal Impact of Fe and Zn on Cd Uptake and Translocation by Theobroma cacao.

High concentrations of toxic cadmium (Cd) in soils are problematic as the element accumulates in food crops such as rice and cacao. A mitigation strategy to minimise Cd accumulation is to enhance the competitive uptake of plant-essential metals. Theobroma cacao seedlings were grown hydroponically with added Cd. Eight different treatments were used, which included/excluded hydroponic or foliar zinc (Zn) and/or iron (Fe) for the final growth period. Analyses of Cd concentrations and natural stable isotope compositions by multiple collector ICP-MS were conducted. Cadmium uptake and translocation decreased when Fe was removed from the hydroponic solutions, while the application of foliar Zn-EDTA may enhance Cd translocation. No significant differences in isotope fractionation during uptake were found between treatments. Data from all treatments fit a single Cd isotope fractionation model associated with sequestration (seq) of isotopically light Cd in roots and unidirectional mobilisation (mob) of isotopically heavier Cd to the leaves (ε114Cdseq-mob = -0.13‱). This result is in excellent agreement with data from an investigation of 19 genetically diverse cacao clones. The different Cd dynamics exhibited by the clones and seen in response to different Fe availability may be linked to similar physiological processes, such as the regulation of specific transporter proteins.

Improving the Productivity and Nutritional Values of Sweet Potato (Ipomoea batatas L.) with a Combination of Soil and Foliar Zinc

Sweet potato (Ipomoea batatas L.) is an important crop and is a staple food in many countries across the globe; since they are a good source of nutrients including zinc (Zn). Zn is essential for plant growth and development, and a zinc deficiency can significantly impact crop productivity as well as the nutritional quality of the produce. The value of enrichment with Zn in many crops by applying Zn either to foliar or soil through agronomic biofortification has been investigated, but this information is still unavailable for sweet potatoes. Therefore, the current study aimed to evaluate the effect of soil and foliar Zn applications on yield, biochemical traits, and nutrient concentrations of different sweet potato genotypes. The study was conducted using a split-plot design with treatments of two doses (0 and 2.5 kg Zn ha-1) of soil application and four doses (0, 15, 30, and 45 ppm) of foliar application of Zn on five sweet potato genotypes (SP-2, SP-14, SP-15, SP-16, SP-20). It was observed that growth and yield performance as well as nutrient concentrations in the tubers of sweet potatoes were greatly influenced by Zn application method and genotype. An increasing rate of foliar Zn, with or without soil-applied Zn, showed an increasing trend in amino acid, β-carotene, flavonoid, and phenolic content. The foliar Zn application had a more obvious effect on most of the examined traits than the soil Zn application and except for a few characteristics (dry matter and amino acids), most traits responded up to the foliar application of 15 ppm Zn, and thereafter no increase was seen with further increments of foliar Zn application.

Agronomic zinc biofortification of potato (Solanum tuberosum) through soil and foliar zinc sulphate application in Rajasthan

An experiment was conducted during winter (rabi) seasons of 2020–21 and 2021–22 at Agricultural Research Station, Kota, Rajasthan to assess agronomical biofortification of potato (Solanum tuberosum L.) through soil and foliar zinc sulphate application The experiment consisted of 7 treatment combination of soil and foliar applications in a randomized block design with 4 replications. The results revealed that the application of ZnSO4 @2.5 kg/ha at the time of planting and foliar application of zinc sulphate @0.2% at 25 and 50 DAP (T7) gave significantly higher total tuber yield, and number of tubers. A significantly higher tuber zinc content was observed under treatment T7, where soil application of ZnSO4 @12.5 kg/ha at planting + 0.2% foliar application of ZnSO4 at 25 and 50 days after planting (DAP) compared to control, indicating more Zn accumulation. The benefit-cost analysis of tuber production under different basal soil application levels and foliar application revealed highest benefit-cost ratio of 2.59 with treatment T7 followed by T6 (2.39) and T3 (2.35). The apparent recovery efficiency and partial factor productivity were also higher with combined application of ZnSO4 through soil as well as foliar application. The experiment highlights the importance of soil and foliar zinc sulphate application for improved tuber yield and zinc fortification in a sustainable and cost-effective manner.

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

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

Effect of Foliar Application of Zinc on Zn-fortification and Morph-Physiological Responses of Rainfed Wheat Yield: A Review

Wheat is a staple food in Pakistan and plays a vital role in the country's agriculture. It is one of the country's most widely cultivated and consumed crops, providing millions of people's food and livelihoods. The study reviewed the literature on the effect of foliar application of zinc on zinc-fortification and the yield of wheat grown under rainfed conditions. The review analyzed a range of studies that investigated the impact of the foliar application of zinc on wheat growth and grain quality. The results showed that foliar application of zinc significantly improves the zinc content of the wheat grain, which has important implications for addressing zinc deficiency in areas where it is prevalent. Additionally, the review revealed that zinc treatment leads to a noticeable increase in wheat yield, demonstrating its potential to improve agricultural productivity in rainfed farming systems. The review concludes by highlighting the need for further research to optimize the application rate and timing of foliar zinc application to maximize its benefits for wheat production under rainfed conditions. GRAPHICAL ABSTRACT

Foliar zinc spraying improves assimilative capacity of sugar beet leaves by promoting magnesium and calcium uptake and enhancing photochemical performance

Sugar beet, a zinc-loving crop, is increasingly limited by zinc deficiency worldwide. Foliar zinc application is an effective and convenient way to supplement zinc fertilizer. However, the regulatory mechanism of foliar zinc spraying on sugar beet leaf photosynthetic characteristics remains unclear. Therefore, we investigated the effects of foliar ZnSO4·7H2O application (0, 0.1%, 0.2%, and 0.4%) on the photosynthetic performance of sugar beet leaves under controlled hydroponic conditions. The results indicated that a foliar spray of 0.2% Zn fertilizer was optimal for promoting sugar beet leaf growth. This concentration significantly reduced the leaf shape index of sugar beet, notably increasing leaf area, leaf mass ratio, and specific leaf weight. Foliar spraying of Zn (0.2%) substantially elevated the Zn content in sugar beet leaves, along with calcium (Ca) and magnesium (Mg) contents. Consequently, this led to an increase in the potential photochemical activity of PSII (Fv/Fo) (by 6.74%), net photosynthetic rate (Pn) (11.39%), apparent electron transport rate (ETR) (11.43%), actual photochemical efficiency of PSⅡ (Y (Ⅱ)) (11.46%), photochemical quenching coefficient (qP) (15.49%), and total chlorophyll content (25.17%). Ultimately, this increased sugar beet leaf dry matter weight (11.30%). In the cultivation and management of sugar beet, the application of 0.2% Zn fertilizer (2.88 mg plant−1) exhibited the potential to enhance Zn and Mg contents in sugar beet, improve photochemical properties, stimulate leaf growth, and boost light assimilation capacity. Our result suggested the foliar application of Zn might be a useful strategy for sugar beet crop management.

Effect of Foliar Application of some Macro and Micronutrients on the Growth and Yield of Maize

Abstract: Maize is the most cultivated cereal crop in Ghana and plays a significant role in consumer diets. An ideal way of improving yield is through the use of balanced macro and micronutrient doses. Fertilizers supplied through soils are subjected to leaching, fixation, surface runoff, erosion, volatilization, extremely high or low pH render nutrients unabsorbable by plants. Foliar application of fertilizer supplies nutrients directly to the stomata and cuticle of the leaves which saves time and increases yield as proposed by crop physiologist. The experiment was designed as a multi-location study comprising eight treatments. These treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replications. The experiment was conducted at the experimental field of University for Development Studies, Nyankpala (9° 24’ 39’’ N, 0° 59’ 2’’ W 170 m) and Kpaliga (9° 26’ 44’’ N, 0° 57’ 58’’ W 170 m) in the Northern region of Ghana. Application of nitrogen in a split form has the ability to broaden the leaf surface area to receive the foliar applied micronutrients. However, increasing nitrogen at basal application and reducing it at top dressing (NP2K treatments) stands a better chance of broadening the leaf surface area. The general progression of leaf area index could be attributed to the adequate supply of macronutrients. NP2K+[P+Zn+Fe] produced the highest grain yield. There was significant difference between foliar zinc and control (NP2K). Maize plants responded to foliar application of phosphorus, zinc and iron, but not in terms of yield differences. It will be needful to repeat this experiment since the drought affected the response of maize to foliar applied fertilizer to yield. Socio economic analysis should be done to show whether the increment in grain yield will compensate for the cost of application of foliar fertilizer.