PLANT GROWTH PROMOTING RHIZOBACTERIA (PGPR) The group of bacteria that colonize roots or rhizosphere soil and beneficial to crops are referred to as Plant Growth Promoting Rhizobacteria (PGPR). Rhizosphere consists of bacteria named rhizobacteria which either directly or indirectly exert positive effects on plants. These soil bacteria colonize plant root and benefit the plants by stimulating its growth and are therefore called plant growth promoting rhizobacteria (PGPR). PGPR can also be referred to as Plant Health Promoting Rhizobacteria (PHPR) The concept of Rhizosphere was first given by Hiltner in 1904. The term PGPR was first coined by Joseph W. Kloepper and Schroth in the late 1970s. Bacteria belonging to the genera Azospirillum sp., Azotobacter sp. , Azoarcus sp., Arthrobacter sp., Klebsiella sp., Burkholderia sp., Citrobacter sp., Pseudomonas sp., Bacillus sp., Paenibacillus sp., Herbaspiril...