Effect of Organic Fertilization on the Physiological Status of Tomatoes under Abiotic Stress

Abstract During the vegetation period of years 2020 and 2021 in experimental field at Agricultural University - Plovdiv it was conducted a physiological study tomato cultivar (Rugby) with determined growth under treatment chemical organic fertilizers. The aims were to determine changes behaviour productivity tomatoes depending on fertilization dates planting. assessment included measuring some parameters chlorophyll fluorescence content index. Chlorophyll has proved have potential detect abiotic stress effects photosynthetic efficiency. This technique used assess intensity plants ( Solanum lycopersicum ), grown different types fertilizer planted three additional – 30.04, 07.05 14.05 conditions ambient heat stress. Results shown slight effect applied upon but significantly improved index compared no variant. Additionally, measured higher for second third planting dates. highest average yield calculated NPK variant, as statistically significant differences between control variants 2021. It possessed date