Plant Growth-promoting Rhizobacteria: Potential Green Alternative for Plant Productivity

Use of plant growth promoting rhizobacteria (PGPR) for the benefits of agriculture is gaining worldwide importance and acceptance and appears to be the trend for the future. PGPR are bioresources which may be viewed as a novel and potential tool for providing substantial benefits to the agriculture. These beneficial, free-living bacteria enhance emergence, colonize roots, stimulate growth and enhance yield. PGPR are known to induce resistance against various plant pathogens in different crops ranging from cereals, pulses, ornamentals, vegetables, plantation crops, spices and some trees. Most studies have emphasized exploration and potential benefits of PGPR in agriculture, horticulture and forestry. The plausible mechanisms adopted by these rhizobacteria in growth promotion and resistance, though abundantly documented but still remains to be fully explored. Integrated use of PGPR allows the combination of various mechanisms thereby enhancing their beneficial abilities. However, their use has not been to the full potential due to inconsistency in their performance and their commercialization limited to few developed countries. Use of PGPR as bioinoculants, biofertilizers and biocontrol agents, advantages and disadvantages, practical potential in improved agriculture and future prospects are also discussed.