The influence of the structure of various isoxazole derivatives on photosynthetic apparatus of tomato plants grown in the field and greenhouse. Effect of various stages of plant growth in different seasons

The aim of this study was to determine how various derivatives of isoxazole affect photosynthetic apparatus of different tomato species grown in a greenhouse and under field conditions. Measurements of chlorophyll fluorescence of photosystem II (PSII) were used as an indicator of the stress induced by isoxazoles on photosynthetic energy conversion. Chlorophyll fluorescence yield provides quantitative information not only on steady-state photosynthesis, but also on various mechanisms of protection against stress-induced damage and the extent to which performance of photosynthesis is limited by photochemical and non-photochemical processes. Measurements were made on tomato plants in various stages of growth (from the 3rd to 15th leaf), in different seasons of the year. The data show that the age of plants does not have a significant influence on Fv/Fm values and it seems that younger plants are more sensitive to the used isoxazole derivatives. Selected isoxazoles did not affect the plant photosynthesis.