Abstract

The extract of the green macroalgae Ulva rigida C. Agardh (Chlorophyta), which is collected from the Azla coast, was investigated in vitro to test its effect on the growth of garden cress (Lipidium sativum) and onion (Allium cepa). Effects of four aqueous concentrations of the seaweed (0.5, 1, 2 and 4mg of dried seaweeds per ml of distillated water) were tested on the growth of seedling roots and stems of 1488 plants of garden cress and onion during two weeks. The comparison tests were carried out with an agar medium and Murashige and Skoog mineral salt medium (1962). The results indicated that extract of U. rigida is suitable for plants development.