§16§Salinity is an increasing problem in many irrigated, arid and semi-arid areas of the world where rainfall is insufficient to leach salts from the root zone, and it is a significant factor in reducing growth and crop productivity. Plant growth promoting rhizobacteria (PGPR) are indigenous to soil and plant rhizosphere. These microorganisms are the potential tools for sustainable agriculture. They enhance the growth of a root system and even of an entire plant and often control certain plant pathogens. Rhizosphere colonization is also considered to be a crucial step in the application of microorganisms for beneficial purposes such as biofertilization, phytostimulation, biocontrol.
