allelopathic effect of rapistrum rugosum l. weed on growth, physiological and biochemical parameters of hibiscus sabdariffa l.

To study the allelopathic effect of decomposed fresh aerial parts of rapistrum rugosum on growth, physiological and biochemical traits of hibiscus sabdariffa, a pot experiment was conducted as a completely randomized design with three replications under greenhouse condition at the gonbad kavous university. treatments were different amounts of r. rugosum residues (0, 10, 20, 40, 80, and 160 g kg-1 soil). the results showed that increasing the amount of r. rugosum residues significantly reduced the growth traits of h. sabdariffa. the lowest amount of stem and root length, fresh and dry weight of the plant was observed in 160 g kg-1 of r. rugosum residues. the content of chlorophyll b and carotenoids, as well as malondialdehyde, decreased with increasing the amount of r. rugosum. however, the trend of changes in the content of catalase enzyme, soluble sugars content, proline, total phenol, and flavonoids increased with increasing the amount of r. rugosum residues. consequently, our findings showed that with the increasing in the amount of r. rugosum residues, all the studied traits of h. sabdariffa decreased significantly. therefore, due to the negative allelopathic effect of r. rugosum on growth and physiological parameters of h. sabdariffa, r. rugosum density management should be considered during the cultivation of this plant.