The Effectiveness of Foliar Applications of Zinc and Biostimulants to Increase Zinc Concentration and Bioavailability of Wheat Grain

Abstract

Increasing zinc (Zn) concentration in wheat grain is an important global challenge due to high incidence of Zn deficiency in human populations. In this study, a two-year field experiment was conducted to investigate the effects of foliar ZnSO4 combined with various biostimulants (fulvic acid (FA), seaweed extract (SE), amino acids (AA), and microbial incubates (MI)) on Zn concentration and bioavailability in wheat grain under different soil nitrogen (N) levels (0, 120, and 240 kg N/ha). Grain Zn concentration and bioavailability were significantly enhanced by foliar Zn plus various biostimulants and soil N supply. Compared to foliar Zn alone, foliar Zn + FA resulted in 16% increase in grain Zn, mainly from insoluble Zn increases, while foliar Zn + AA caused 11% increase in grain Zn, mainly from soluble (at N0) and insoluble Zn increases (at N120). Foliar Zn + FA and Zn + AA generally resulted in higher Zn bioavailability than foliar Zn alone. Additionally, N concentration and Fe concentration and bioavailability in grain were enhanced with foliar Zn + AA and soil N application. Thus, foliar ZnSO4 plus FA and AA under optimal soil N rate (120 kg N/ha) can be an effective and economically friendly approach for achieving agronomic biofortification.

Biostimulant Effects of Glutacetine® and Its Derived Formulations Mixed With N Fertilizer on Post-heading N Uptake and Remobilization, Seed Yield, and Grain Quality in Winter Wheat

“…Regarding the strong increases of seed yields (from 11 to 52%), our findings showed slight reduction in Fe (−5 to −17%) and Zn (−1 to −14%) contents. In contrast, it has been recently demonstrated that biostimulants enhance Zn concentration and bioavailability in wheat grain (Wang et al, 2020;Yadav et al, 2020). Nevertheless, in our study, the amount of Fe and Zn exported was significantly higher for VNT4 at dose 3 than for the control group (data not shown), which might be due to better remobilization during monocarpic senescence.…”

“…A downregulation of these proteins, while still maintaining dough proprieties, might be a solution for celiac disease patients (Altenbach et al, 2020). Beyond N, mineral nutrients in grain act as a source of micronutrients in the human diet, among which deficiencies in key minerals including calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), and zinc (Zn) have prompted efforts to increase their concentrations in seeds (Kutman et al, 2010;Hussain et al, 2012;Ramzani et al, 2016;Rehman et al, 2018;Wang et al, 2020). In the last few decades, it has been well established that wheat is a crucial source of Fe and Zn for humans (Uauy et al, 2006;Ciccolini et al, 2017;Singh et al, 2018), but the concentrations of these minerals in flour are generally low (Sobolewska et al, 2020), and their bioavailability is limited by high phytate content (Ficco et al, 2009;Xue et al, 2015).…”

Linking abiotic stress, plant metabolites, biostimulants and functional food

“…However, the research of de Vasconcelos (2019) showed no effect of the tested biostimulants applied in the recommended dosages on nutrient content in wheat and maize aerial parts, which is an evidence that biostimulants cannot replace standard fertilisation of high nutrient demanding crops. Accordingly, the results of Wang, Tian, and Liu (2020) showed that foliar ZnSO 4 treatment plus fulvic acids and amino acids can be an effective and economically friendly approach for achieving agronomic Zn‐biofortification, under optimal soil N rate (120 kg N ha −1 ) for wheat. de Vasconcelos and Garófalo Chaves (2019) highlight that they are efficient in small concentrations, enhancing nutrition efficiency, abiotic stress tolerance and/or crop quality traits, regardless of their nutrients content.…”

Preference of Pollinators over Various Forage Mixtures and Microelement Treatments

“…(a) Control (without application of Zn and Se); (b) Foliar application of Se: 20 g Se ha −1 (in 250 L water ha −1 ) (form Na2SeO3) [38]; (c) Foliar application of Zn: 200 g Zn ha −1 (in 250 L water ha −1 ) (form ZnSO4×7H2O) [45]; (d) Foliar application of Se and Zn: 20 g Se ha −1 (form Na2SeO3) + 200 g Zn ha −1 (all in 250 l water ha −1 ) (form ZnSO4×7H2O).…”