Changes in Plant and Grain Quality of Winter Oat (Avena sativa L.) Varieties in Response to Silicon and Sulphur Foliar Fertilisation under Abiotic Stress Conditions.

In order to investigate the abiotic stress (drought) tolerance of oat (Avena sativa L.) with silicon and sulphur foliar fertilisation treatments, and monitor the effect of the treatments on the physiology, production, stress tolerance, plant, and grain quality of winter oat varieties, a field experiment was conducted in the growing season of 2020-2021. As a continuation of our article, published in another Special Issue of Plants, in this publication we evaluate the effect of silicon and sulphur treatments on the quality of winter oats. The whole grain sulphur content was significantly different between varieties. The foliar fertiliser treatments caused greater differences in both the carbon and nitrogen, and sulphur contents in the green plant samples, compared to the differences measured in the grain. Foliar treatments had a significant effect on the sulphur content of both plant samples and grains. Significant differences in the Al, Ba, Ca, Cu, Fe, K, Mn, Mo, Na, Ni, P, Pb, Sr, and Zn contents of oat grains were measured, both between treatments and between varieties. Winter oat varieties did not respond equally to the foliar fertiliser treatments in terms of either macronutrient or micronutrient content. When P, K, Ca, Mg, and S were summarised, the highest values were in the control plots. Significant differences in protein content were identified between winter oat varieties in response to the treatments, but the varieties did not respond in the same way to different foliar fertiliser treatments. Based on our results, we recommend the use of foliar fertilisation in oats in drought-prone areas.

Examination of honeys and flowers as soil element indicators.

Detection of soil element deficiencies is time consuming, requiring a major commitment for field work and analysis. Bees concentrate some elements in their honey which could allow soil element concentrations to be predicted without having to take large numbers of soil samples. We measured 14 element concentrations in soil, sunflower, acacia flower and honey samples from two different regions of Hungary. Across sites, the elements with significant correlation coefficients between honey and soil concentrations, in descending order of probability, were Cu > Ba >Sr = Ni > Zn > Mn = Pb >As. Bioconcentration from soil to honey was similar for areas with acacia and sunflower flowers. In the macroelements, it was the greatest for K, S and P and least for Mg and Na, and in the microelements, greatest for B, then Zn, then Cu, then As, Mo and Sr and least for Fe, Ba, Mn and Pb. It is concluded that in acacia and sunflower-growing regions, honey can give an accurate estimate of soil element concentrations for Cu and Ba and provides relevant information for Sr, Ni, Zn, Mn, Pb and As.