During the vegetation period of the years 2020 and 2021 in the experimental field at Agricultural University - Plovdiv it was conducted a physiological study of tomato cultivar (Rugby) with determined growth under the treatment with chemical and organic fertilizers. The aims of the study were to determine the changes in physiological behaviour and productivity of field tomatoes depending on the fertilization and dates of planting. The physiological assessment included the measuring of some parameters of chlorophyll fluorescence and chlorophyll content index. Chlorophyll fluorescence has proved to have the potential to detect abiotic stress effects on photosynthetic efficiency. This technique was used to assess growth intensity in tomato plants (