Infusing Microbial Consortia on Seed Quality and Seedling Vigour in Pearlmillet [Pennisetum glaucum (L.) R. Br.]

Aim: Seed treatment with Plant Growth Promoting Bacteria (PGPB) is considered to be safe for seed and environment and ecologically sound. To ensure the benefits of the PGPB, studies were conducted in pearlmillet by treating with liquid microbial cultures for enhancing seed germination and seedling vigour.

Methods: The pearlmillet seeds were infused with different concentrations of liquid microbial cultures and their consortia. Also, the bioinoculant infused seeds were treated with chemicals to assess their effect on the microbial population.

Results: The pearlmillet seeds soaked in equal volume of Azospirillum or phosphobacteria @ 1:50 dilution or Pink Pigmented Facultative Methylotroph (PPFM) @ 1:100 dilution for 18 h have recorded higher germination and seedling vigour. Pink Pigmented Facultative Methylotroph treated seeds have showed higher germination and seedling vigour amid the microbial cultures. In addition, the bioinoculant treated seed viability and vigour were not affected during three months storage. However, the microbial populations in the seed get declined during storage. The microbial consortia comprising of Azospirillum, phosphobacteria and PPFM did not affect the germination rather seedling vigour. Besides, seeds infused with Azospirillum @ 1:50 dilution and PPFM @1:100 dilution (1:1) for 18 h have recorded higher seedling vigour. In addition, seeds soaked in PPFM @1:100 dilution for 18 h followed by polymer coating @ 5 ml kg-1 and carbendazim seed treatment @ 2 g kg-1 of seed had higher germination and seedling vigour. But, the microbial population in the seed was reduced considerably due to the chemical treatment.

Conclusion: The liquid bioinoculants viz., Azospirillum, phosphobacteria and PPFM can be used to pre-inoculate the pearlmillet seeds with required population to be carried over to the field.