In recent years, the popularity of using unmanned aerial vehicles (UAVs) for environmental and agricultural purposes has increased because of their practicality and non-invasiveness. In the present study, five Hungarian winter oat (Avena sativa L.) varieties were involved into a field experiment to evaluate their response and tolerance to drought stress influenced with three different foliar fertilization treatments based on silicon, sulfur and the combination of both elements (Si, S, SiS) in the growing season of 2021-2022. Wide range of information from aerial surveys which includes vegetation indices from multispectral sensor, surface temperature and crop height from LiDAR payloads were evaluated in their interaction with production features such as yield, thousand kernel weight and grains moisture, with the objective to monitor the effects of the drought stress and the foliar fertilization treatments in the status of the plants at its different phenological stages. The results showed that the silicon-sulfur combined fertilization caused the most advantageous changes in the crop in term of NDVI, NDRE, plant height, temperature and yield. The statistical correlations show a positive and strong link between the average yield and the UAV parameters of NDVI and NDRE and in negative way with the crop temperature, however, in the study of the treatments and varieties separately, statistical divergences were also found with the same trend but in unequal scale, showing the contribution of the genotype in the resistance and effects of the abiotic stress. These results effectively support the use of UAVs to assess field experiments and obtain information about the tolerance of different varieties of winter oat towards the water stress and consequently propose alternatives and solutions that counteract the effects of climate change and weather variability in the crops that can put their yield at risk and furthermore the food security.