Ecological vegetable cultivation is based on the protection and nutrition of plants with organic preparations. Tomatoes are one of the most important vegetable plants that are grown in our area. For our research, tomato plants were planted infield, we determine the development of late blight (Phytophthora infestans) on them and the influence of organic fertilization treatment on the number and weight of the fruits and the intensity of the disease. The following treatments were carried out in an experimental trial: organic fertilization treatment (vermicompost) - soil watering (Gz), organic fertilization treatment (vermicompost) - soil watering and spraying of the overhead parts of the plant (Gz + Gp), treatment with fungicide - Penncozeb 75 DG (F) and control treatment - without application of organic fertilizer (vermicompost) or fungicide (K). Late blight occurred with lower intensity and the disease index ranged from 0.04 (Gz + Gp) to 0.08 in the control treatment. The highest average number of fruits per repetition was found with treatment of soil watering and spraying of the overhead parts of the plant (Gz + Gp). However, there is no statistically significant difference between this treatment and the fungicide treatment. The smallest number of fruits were found in the control treatment. Statistically significant yields were recorded in the treatment of soil watering and spraying the overhead parts of the plant with organic fertilizer (vermicompost) (Gz + Gp) and with fungicide-treated plants.