Seed treatment with liquid microbial consortia for germination and vigour improvement in tomato (Solanum lycopersicum L.)

Use of effective microorganisms as a pre-sowing seed treating agent is considered to be ecologically sound and beneficial to both seed and environment. Therefore to ensure the benefits, studies were conducted in tomato seeds with different liquid microbial cultures. The results revealed that the tomato seeds treated with liquid cultures viz., Azospirillum, phosphobacteria and Pink Pigmented Facultative Methylotroph (PPFM) have showed significant increase in germination and vigour. The seeds soaked in equal volume of Azospirillum @ 1:50 dilution for 24 h or phosphobacteria @ 1:50 dilution for 12 h or PPFM liquid culture @ 1:100 dilution for 18 h have registered the higher germination and vigour. Among these microbial cultures, PPFM has performed well in enhancing the seed germination and seedling vigour. Also, the viability and vigour of the inoculants infused seed were not much affected in three months storage. However, consortia of these microbial cultures showed antagonistic effect in seed germination and seedling vigour. In addition, the seeds infused with PPFM @1:100 dilution for 18 h followed by polymer coating @ 5 mL and carbendazim fungicide treatment @ 2 g kg-1 recorded significant improvement in seed germination and vigour with minimal reduction in the microbial population. Therefore, it would be possible to infuse the beneficial microbes into the seed through liquid cultures and also storing such seeds without much reduction in the microbial population. Therefore, it is beneficial if the seeds treated with the effective microorganisms which favour the better seed germination and seedling growth. Also, the microbes can easily be added into the soil along with the seed which may reflect on the better coloization of the microbes in plant root zone.