Seed and seedling vigour improvement through seed infusion with liquid microbial consortia in sorghum, Sorghum bicolor (L.) Moench

Seed treatment with bioinoculants is being considered as an important valuable event equally to seed and environment. Though the carrier-based inoculants are being followed, it has short shelf life and difficult to use for large quantities of seed. Hence, studies were carried out in sorghum by infusing liquid microbial cultures to find out their effect on seed vigour and microbial population in the seed. The results showed that the sorghum seeds soaked in equal volume of Azospirillum @ 1: 50 dilution for 18 h or phosphobacteria @ 1: 50 dilution or PPFM @ 1: 100 dilution for 12 h performed better in germination and vigour improvement. Among these microbial cultures, PPFM had highest seed germination and seedling vigour. Also, the viability and vigour of the seeds infused with bioinoculants were not affected much in three months storage. The microbial consortia comprising Azospirillum @ 1: 50 dilution and PPFM @ 1: 100 dilution (1: 1) for 18 h had highest germination (99%). Likewise, seed soaking in PPFM @ 1: 100 dilution for 18 h followed by polymer coating @ 5 ml/kg and carbendazim seed treatment @ 2 g/kg of seed showed significant increase in germination (97%), speed of germination (10.8) and seedling length (39.9 cm) with slight reduction in the microbial population.