Allelopathic Potential of Ferulic Acid on Tomato

This study deals with allelopathic effects of exogenous application of ferulic acid (FA) on biophysical and biochemical parameters of tomato (cv. Pusa ruby) seedlings grown in hydroponic culture. FA exhibited phytotoxic effects on tomato seedlings grown in a Hoagland solution. After 7 days of seedling growth, FA was added to the growth medium at concentrations of 0.1, 0.5, 1.0, and 1.5 mM. The Hoagland solution without FA was used for experimental units. The root and shoot length, fresh and dry weight of seedlings, chlorophyll a (chl a), chlorophyll b (chl b), total chlorophyll (chl t), carotenoids, protein and sugar content, nitrate reductase (NR) activity and antioxidant enzymes accumulation were examined in 25 days time period. FA exhibited significant inhibitory effects on some biophysical and biochemical traits. A gradual decrease in all studied traits in FA based-treatments was observed. The root and shoot length, the fresh and dry weight of the seedlings significantly decreased in a dose dependent manner under FA allelopathic potential. The chl a, chl b, chl t and carotenoids contents decreased with the increase of FA concentrations. A significant reduction in sugar and protein contents and in NR activity was recorded especially with the highest concentrations of FA used. Higher FA concentrations significantly enhanced the activities of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX)] which appeared as a form of tolerance and/or a defense to allelochemicals used.