EFFECT OF ANABAENA VAGINICOLA INOCULUM ON GROWTH OF POT PLANTS

Although much attention has been paid to study of nitrogen fixation by blue-green algae in paddy fields, algae are also beneficial for plant by producing plant - growth promoters like auxins, cytokinins, abscisic acid and ethylene. Monoalgal cultures was carried out by growing the isolates in nitrate free BG-11 medium in two liter container at 24° and a 12/12 h light-dark cycle at artificial illumination (2,000-2,500 Lux) with constant stirring and aeration. After three weeks culture was harvested and used as an inoculum. Five healthy seedlings were grown in 1 liter pots (14 cm diam.) including 60% peat, 25% sand and 15% normal soil. No fertilizer was applied, but 400 milliliters algal suspension (OD=0.3) was sprayed on treated and BG-11 medium for untreated pots. The pots were arranged in a completely randomized design in an experimental greenhouse. Growth of plants was evaluated by measuring plant height, root length, number leaf and flowers after 50 days planting. From the results described in this paper, it is clearly showed that the algal culture contained some substances that can promote growth of the plants. Result of this finding also has led to the recognition that addition of algal inoculums positively affected plant height and plant root length.