Allelopathic effects of cassava (Manihot esculenta crantz) on radish (Raphanus sativus L.) and ryegrass (Lolium perenne L.)

We studied the mechanisms of cassava (Manihot esculenta crantz) allelopathy on radish (Raphanus sativus L.) and ryegrass (Lolium perenne L). The water leachates from cassava leaves inhibited the seed germination and seedling growth of both receptor plants decreased the root vigour and chlorophyll content. However, the permeability of cell membrane and MDA content were significantly increased. The leachates spray at >0.025 g·ml⁻¹ concentration decreased the soluble protein in seedlings of both receptor plants, but increase the activity of POD. Contrarily, the leachates application <0.0125 g.ml⁻¹ concentration increased the content of soluble protein and reduced the activity of POD. While between 0.05 g.ml⁻¹ and 0.0125 g.ml⁻¹ concentrations, the leachates enhanced the PAL activity of both receptor plants. Spraying of leachates increased the activities of SOD and PPO in the seedlings of radish and ryegrass but decrease the PPO.