A fungicide study was carried out in lupin (Lupnis albus L.) and common vetch (Vicia sativa L.) plants on the sandy soil of the AKIT Nyíregyháza Research Institute of the University of Debrecen, Hungary, the number of literature sources on plant protection in these small crops is limited. Various fungal diseases can set back plant development and negatively affect yields, and the vitality of harvested seeds is also important. In both crops, three treatments were applied in mid-June: tebuconazole + prochloraz, mefenoxam + mankoceb and azoxistrobin + cyproconazole. NDVI data were collected using the Trimble GreenSeeker HCS-100 device to monitor vegetation changes. After harvest, the harvested crop was cleaned in the Westrup Kamas laboratory seed cleaner and the amount of crop residue was documented. In addition, we documented the different seed yields and then placed the seeds on Papavizas substrate for seed infection testing. According to the NDVI values recorded in the lupin plots, the highest average NDVI value was recorded in the tebuconazole + prochloraz treated plots after fungicide treatment. The least infested seed according to both dates of recording also came from plots treated with tebuconazole + prochloraz, but these plots did not perform particularly well in terms of seed yield. Based on NDVI values following common vetch fungicide treatment, the highest average NDVI values were found in plots treated with tebuconazole + prochloraz. In the seed infestation test, the control plots had the lowest number of infected seeds at the first evaluation, and at the second evaluation, seeds from plots treated with azoxistrobin + cyproconazole had the lowest number of fungal infected seeds. Based on harvested seed yield values, none of the fungicide treatments caused yield increases in any of the examined plants. No significant difference was found, but the average seed yield of the control plots was the highest for both crops. Some of the active substances used have been or will be removed soon, therefore, new active substances should be included in the research.