PHYTOTOXIC EFFECTS OF Calotropis procera EXTRACT ON GERMINATION AND SEEDLING VIGOR OF WHEAT

Numerous plants are recognized for their phytotoxic and inhibitory influence on growth of cultivated crops. This study was conducted to probe the allelopathic effect of Calotropis procera water extract on the seed germination and seedling vigor of wheat. C. procera extract with 1:20 w/v concentration was applied on three different germination media (blotter paper, sand and soil) in addition to wheat seed soaking in C. procera extract. Seed germination percentage and seed germination index were significantly reduced up to 48.30% and 33.27%, respectively. Whereas, mean germination time and time to 50% germination were significantly increased up to 69.56% and 82.48%, respectively with the extract of C. procera, as compared to distilled water (control). A significant reduction of 133%, 222% and 80.77% in root, shoot length and seedling biomass were observed by applying C. procera extract. Seedling vigor index was also declined up to 87.23% with C. procera extract irrespective of germination media. Application of C. procera extract on soil media had a greater inhibitory effect than that of other germination media or seed soaking. It is concluded that presence of C. procera in wheat field may retard the germination and seedling vigor of wheat plants.