Efficacy of liquid formulation of versatile rhizobacteria isolated from soils of the North-Western Himalayas on <i>Solanum lycopersicum</i>

Abstract

In the present study, a total of 53 indigenous diazotrophs and phosphate solubilizing bacteria (PSB) were isolated from the rhizosphere soils of five different crops grown in Palampur, (Himachal Pradesh, India). Out of these, isolates WT-A1 and WT-A2 exhibited significantly higher nitrogenase activity as compared to the reference strain <em>Azotobacter chroococum </em>and PT-P2 solubilized more phosphate as compared to the reference strain <em>Pseudomonas striata</em>. WT-A2 and PT-P2 showed multiple plant growth promoting traits including indole acetic acid, ammonia and siderophore production. On the basis of morphological, biochemical and 16S rRNA gene sequence analysis, WT-A2 and PT-P2 were identified as <em>Stenotrophomonas </em>sp. and <em>Burkholderia cepacia</em>, respectively. The liquid formulation of efficient diazotroph and PSB was prepared in sterilized liquid manure, <em>matka khaad</em> with the addition of trehalose which maintained their viable counts for one year. Evaluation of growth performance of liquid formulation on <em>Solanum lycopersicum</em> (Avtar 7711) <em>in vivo</em> concluded that seed bacterization (SB) and seed bacterization, seedling dipping, soil application and foliar spray (SB+SD+SA+FS) exhibited better results in terms of seed germination, fruit quality, dehydrogenase activity and available nitrogen, phosphorus and potassium of soil as compared to the other treatments.