long-term survivability of stress tolerant azospirillum strains in different inoculant carriers and its field level evaluation at graded n levels

Stress tolerantAzospirillum strains (ATT-3 and AST-1) on comparison with reference strain (MTCC-125) were found to superior in survival in different inoculant carriers. However the degree of survivability varied among the different carriers. Sterilized lignite sustained the highest number of viable Azospirillum cells, followed by unsterilized lignite, sterilized pressmud and unsterilized pressmud. A field trail was also conducted to study the efficiency of these strains at graded nitrogen levels. Azospirillum cells were also found to be superior in augmenting the growth and yield of sunflower.