Allelopathy of Sage and White Wormwood on Purslane Germination and Seedling Growth

Abstract

A bioassay run was carried out in the incubator to evaluate possible allelopathic effects of water extracts of sage and white wormwood on germination and seedling growth of purslane. Results showed that the type of extract and its concentration (0, 5, 10, 15 and 20%) significantly influenced final germination percentage, germination rate and index, root and shoot length, root/shoot ratio, fresh and dry weight of seedling of purslane. The interaction between these two experimental factors was always significant, producing different results according to the different combination levels. The statistical comparison of means indicated that the maximum germination percentage and germination rate (respectively 68% and 11.4% d-1) were obtained from the untreated control (0% extract), while the lowest values for the same two characters occurred with 15% of sage (respectively 45% and 6.4% d-1) and 20% of white wormwood (38% and 7.5% d-1). Concerning germination indexes, the highest (55) and the lowest (32) values were observed respectively on the control and with 15% of sage extract or 20% of white wormwood extract. The longest (4.5 cm) and the shortest (1.3 cm) root of purslane were obtained with 5% of white wormwood and 20% of sage extracts, respectively. Changes in shoot length with sage and white wormwood extracts were similar to those in root length, even though shoot length was less affected by the concentration of extracts. Root and shoot length changes brought to maximum (22.0) and minimum (8.9) values for the root/shoot length ratio, respectively with 5% of white wormwood and 20% of sage extracts. The maximum fresh (2.111 g) and dry (0.338 g) seedling weight of purslane were obtained from untreated control, producing the same seedling weight with 5% of sage, 5 and 10% of white wormwood extract. While the minimum fresh (0.692 g) and dry (0.111 g) seedling weight were obtained from 15% of white wormwood extract, so that there is no significant differences between this value and the seedling weight produced under 10, 15 and 20% of sage and 20% of white wormwood extract.