Glyphosate reduced seed and leaf concentrations of calcium, manganese, magnesium, and iron in non-glyphosate resistant soybean

Greenhouse experiments were conducted to study the effects of glyphosate drift on plant growth and concentrations of mineral nutrients in leaves and seeds of non-glyphosate resistant soybean plants (Glycine max, L.). Glyphosate was sprayed on plant shoots at increasing rates between 0.06 and 1.2% of the recommended application rate forweed control. In an experiment with 3-week-old plants, increasing application of glyphosate on shoots significantly reduced chlorophyll concentration of the young leaves and shoots dry weight, particularly the young parts of plants. Concentration of shikimate due to increasing glyphosate rates was nearly 2-fold for older leaves and 16-fold for younger leaves compared to the control plants without glyphosate spray. Among the mineral nutrients analyzed, the leaf concentrations of potassium (K), phosphorus (P), copper (Cu) and zinc (Zn) were not affected, or even increased significantly in case of P and Cu in young leaves by glyphosate, while the concentrations of calcium (Ca), manganese (Mn) and magnesium (Mg) were reduced, particularly in young leaves. In the case of Fe, leaf concentrations showed a tendency to be reduced by glyphosate. In the second experiment harvested at the grain maturation, glyphosate application did not reduce the seed concentrations of nitrogen (N), K, P, Zn and Cu. Even, at the highest application rate of glyphosate, seed concentrations of N, K, Zn and Cuwere increased by glyphosate. By contrast, the seed concentrations of Ca, Mg, Fe and Mn were significantly reduced by glyphosate. These results suggested that glyphosatemay interfere with uptake and retranslocation of Ca, Mg, Fe and Mn, most probably by binding and thus immobilizing them. The decreases in seed concentration of Fe, Mn, Ca and Mg by glyphosate are very specific, and may affect seed quality

Effect of cadmium stress on growth and mineral composition of two tobacco cultivars

Cadmium (Cd) is a hazardous pollutant for humans, animals and plants when the certain threshold concentrations exceeded. Tobacco can accumulate higher concentrations of Cd, and the genotypic differences of tobacco in Cd uptake and the response to Cd have not been clearly determined. The aim of this work was to determine the effects of various cadmium levels (Cd 0, 0.25, 2.5 and 10 mg kg(-1)) on macro and micro nutrient concentrations and biomass production of two tobacco varieties. Tobacco plants were grown under controlled conditions, and required macro (N, P and K) and micro (Fe and Zn) nutrients were applied along with increased doses of Ccl. The concentrations of N. P. K, Ca, Mg, S, Fe, Cu, Zn, Mn, B and Cd concentrations in leaves and dry matter yield of two tobacco varieties were determined. The increased doses of Cd significantly affected (P < 0.05) the dry matter yield and many nutrient concentrations evaluated. The changes in plant nutrient concentrations of tobacco leaves induced by Cd exposure were diverse. Concentrations of K, Ca, Mg, Zn, Fe, Mn and B decreased in the tobacco leaves in line with Cd exposure, concentrations of Cd and Cu increased, but N, P and S were not significantly changed. The results revealed that high Cd accumulation is possibly associated with a decline in dry matter weight induced by the disturbance of nutrient uptake. Precautions need to be taken for tobacco grown in Cd contaminated environments preventing Cd uptake of human through smoking cigarette

Biofortification of Silage Maize with Zinc, Iron and Selenium as Affected by Nitrogen Fertilization

Agronomic biofortification is one of the main strategies for alleviation of micronutrient deficiencies in human populations and promoting sustainable production of food and feed. The aim of this study was to investigate the effect of nitrogen (N)fertilization on biofortification of maize crop (Zea mays L.) with zinc (Zn), iron (Fe) and selenium (Se) grown on a micronutrient deficient soil under greenhouse conditions. Factorial design experiment was set under greenhouse conditions. The experiment consisted of two levels of each N, Zn, Fe and Se. The levels for N were 125 and 250 mg N kg−1 soil; Zn were 1 and 5 mg Zn kg−1 soil; levels of Fe were 0 and 10 mg Fe kg−1 soil; levels of Se were 0 and 0.02 mg Se kg−1 soil. An additional experiment was also conducted to study the effect of the Zn form applied as a ZnO or ZnSO4 on shoot growth, shoot Zn concentration and total shoot Zn uptake per plant. Shoot Zn concentrations increased by increasing soil Zn application both with ZnSO4 and ZnO treatments, but the shoot Zn concentration and total Zn uptake were much greater with ZnSO4 than the ZnO application. Under given experimental conditions, increasing soil N supply improved shoot N concentration; but had little effect on shoot dry matter production. The concentrations of Zn and Fe in shoots were significantly increased by increasing N application. In case of total uptake of Zn and Fe, the positive effect of N nutrition was more pronounced. Although Se soil treatment had significant effect, N application showed no effect on Se concentration and accumulation in maize shoots. The obtained results show that N fertilization is an effective tool in improving the Zn and Fe status of silage maize and contribute to the better-quality feed

Grain concentrations of protein and mineral nutrients in a large collection of spelt wheat grown under different environments

A large number of spelt wheat genotypes (ranging from 373 to 772) were evaluated for grain concentrations of protein and mineral nutrients under 6 different environments. There was a substantial genotypic variation for the concentration of mineral nutrients in grain and also for the total amount of nutrients per grain (e.g., content). Zinc (Zn) showed the largest genotypic variation both in concentration (ranging from 19 to 145 mg kg(-1)) and content (ranging from 0.4 to 4.1 mu g per grain). The environment effect was the most important source of variation for grain protein concentration (GPC) and for many mineral nutrients, explaining between 37 and 69% of the total sums of squares. Genotype by environment (G x E) interaction accounted for between 17 and 58% of the total variation across the minerals. GPC and sulfur correlated very significantly with iron (Fe) and Zn. Various spelt genotypes have been identified containing very high grain concentrations of Zn (up to 70 mg kg(-1)), Fe (up to 60 mg kg(-1)) and protein (up to 30%) and showing high stability across various environments. The results indicated that spelt is a highly promising source of genetic diversity for grain protein and mineral nutrients, particularly for Zn and Fe