Abstrait

The effect of plant growth-promoting Bacillus species on growth, nutrient, and hormone content of cabbage (Brassica oleracea).

Abdissa Deberssa Gutama

Like any other living things plants also need food for their development, growth and productivity. So there are 16 essential elements which are required by plants for healthy development and productive growth. Agricultural chemical application has been used for a long time. This is the rout terrestrial and aquatic pollution; and ecological destruction. So it is must to replace pollutant source with eco- friendly approaches. Rhizobacteria, Strains of Bacillus species, including B. subtilis, B. cereus, B. amyloliquefaciens, B. pumilus, B. pasteurii, B. mycoides, B. sphaericus, P. polymyxa, P. azotofixans, and B. endophyticus influence the growth, development, and yield of crops under controlled and varied natural conditions either directly or indirectly through various mechanisms. Bacillus species like any other PGPR has capacity to induce plant growth promotion by either direct or indirect modes of action. Bacillus is the most abundant genus in the rhizosphore which has the ability to secrete and release a number of metabolites that are released by these strains, which strongly influence the nutrient availability of the plants. This is through direct mechanisms; by producing bacterial volatiles phyto-hormones which has stimulatory role and, reduction of the ethylene level in plant, upgrading plant nutrient status (liberation of phosphates and micronutrients from insoluble sources; non-symbiotic nitrogen fixation) and prompting disease-resistance mechanisms (induced systemic resistance).