Nitrogen Fixing Diazotroph Azospirillum And Phosphobacteria On The Growth And Development Of Crossandra (Crossandra Infundibuliformis L.)

Crossandra plants bearing very attractive and colourful flowers for more than four months in a year by consuming minimum amount of chemical fertilizers. Azospirillum and phosphobacteria are biofertilizers which induces or enhances the growth, development and yield of crop plant through ‘N’ fixation, ‘P’ solubilization and also by synthesizing growth promoting substances like IAA, GA and cytokinines. In the present investigation about six isolates of Azospirillum were isolated from roots of Crossandra from different locations of Cuddalore District, Tamilnadu, India. Among the six isolates one of the best isolate AVCR* was selected and used in the field studies along with phosphobacteria from the Department of Microbiology, Annamalai University. The present results revealed that the Crossandra plants receiving 75 per cent recommended dose of NPK fertilizers along with Azospirillum and phosphobacteria (T10¬) registered maximum growth and yield when compared to other treatments and also the treatments T6 and T14 registered appreciable values in growth and yield of Crossandra, particularly the treatment T6 – 100 per cent NPK + Azospirillum and phosphobacteria registered nearly on par values with T10 in many growth parameters. Hence there are lot of ways to reduce 25 per cent of N and P fertilizers by intending Azospirillum and phophobacteria to the flower crop Crossandra.