Development of non-sterile inorganic carrier-based formulations of fluorescent pseudomonad R62 and R81 and evaluation of their efficacy on agricultural crops

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment ecosystems & environment, 2010-10, Vol.46 (2), p.251-258
• Main Authors: Saharan, Krishna, Sarma, M.V.R.K., Srivastava, Rashmi, Sharma, A.K., Johri, B.N., Prakash, A., Sahai, Vikram, Bisaria, V.S.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; antimicrobial properties; biofertilizers; Bioinoculant formulation; Bioinoculant shelf life; Biological and medical sciences; black gram; Chemical, physicochemical, biochemical and biological properties; dry matter accumulation; dry matter partitioning; Fluorescent pseudomonads; Fundamental and applied biological sciences. Psychology; inoculant formulations; microbial contamination; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plant growth promotion; plant growth-promoting rhizobacteria; Pseudomonas; shelf life; Siderophores; silicates; soil inoculation; Soil science; storage conditions; talc; Triticum aestivum; Vigna mungo; wheat
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/j.apsoil.2010.08.004

▶ Siderophore and DAPG improved efficacy of non-sterile bioinoculant formulations. ▶ Viability of the pseudomonads in talc-based formulations was retained for a year. ▶ The pseudomonads improved growth of Vigna mungo and Triticum aestivum crops. Talc and aluminum silicate powders were used to develop inorganic carrier-based formulations of fluorescent pseudomonad strains R62 and R81. The aerobically cultivated cell-free broth of both the strains contained a hydroxamate-type siderophore and an antibiotic 2,4-diacetylphloroglucinol (DAPG). The formulations of these bioinoculants were able to bring the natural contaminants in the non-sterile carriers to acceptable limits in the presence of 54.6 μg g −1 of siderophore and 10 μg g −1 of DAPG. The shelf life of talc powder-based formulation was about 1 year in comparison to about 100 days for aluminum silicate-based formulation. Both sterile and non-sterile carrier formulations worked significantly well in comparison to their controls for growth of Vigna mungo and Triticum aestivum crops. Sterile talc powder-based formulation of strain R81 showed maximum increase in dry root weight, dry shoot weight, and root volume of Vigna mungo over that with aluminum silicate-based formulation. On Triticum aestivum, the growth response was better in the case of R62-treated seeds in comparison to treatment with R81. However, a consortium of talc powder formulation of R62 and R81 gave the best increase of 46% for sterile and non-sterile carriers in grain yield of Triticum aestivum over respective controls.