These two isolates were further tested for their potential as plant growth promoters under nitrogen availability (0.35 gl-1 potassium nitrate), together with three other isolates selected on the basis of their in vitro activities related to plant growth promotion : isolate G2Ec2 (pantoea sp.) Was included due to the high capacity of auxin production from tryptophan (127.1 ug ml-1 culture); isolate G1Dc10 (pseudomas sp.) Was selected on basis of the high in vitro phosphate solubilization and siderophore production activities (haloes size of 4.2 and 8.3 mm, respectively ); isolate G3Ac9 (paenibacillus sp.) Was chosen for the high hydrolytic activities towards .