Plant growth promoting microbes associate with Pongamia and Jatropha plants
Plant growth promoting bacteria are important for plant nutrition by increasing N and P uptake by the plants, and playing a significant role as plant growth promoting rhizobacteria (PGPR) in the biofertilization of crops.
The present study was done on the plant growth promoting microbes associate with Pongamia and Jatropha plants. Soil samples were collected from Pongamia and Jatropha fields. Enumeration of microbes (bacteria, fungi, Actinomycetes) was done by the dilution plating technique using appropriate media. Mean microbial population was found to be more (9×105 cfu g-1 of soil) in Pongamia field.
Enumeration of specific microbes (Pseudomonas, non-symbiotic nitrogen fixing bacteria and Siderophore producing bacteria) was done by the dilution plating technique with appropriate media. The results showed significant difference between the two crops Pongamia and Jatropha for specific microbial enumeration parameters. Mean specific microbial count (9×104 cfu g-1 of soil) was found to be high in Pongamia field. The effect of PGPB on Jatropha seeds, collected from various locations i.e. ICRISAT, Velchal and Kothapally were studied by inoculating the seeds with nonsymbiotic nitrogen fixing bacteria and Siderophore producing bacteria.
Significant difference was observed in the seeds collected from Kothapally inoculated with nonsymbiotic nitrogen fixing bacteria, where the root length and shoot length (10 cm and 15 cm) was observed to be more when compared to that of seeds collected from other areas and Siderophore producing bacteria.The out come of this experiment necessities further studies on PGPB to study the effect of high growth in cropping systems.