Growth enrichment of Carthamus tinctorius (L) and reduction in dosage of chemical fertilizers with application of plant growth promoting rhizobacteria

Abstract Experiencing the adverse effects of synthetic chemical fertilizers in agriculture production the concept of biofertilizers has gained interest currently. The aim of the current study was to evaluate the integrated role of plant growth promoting rhizobacteria (PGPR) and chemical fertilizers on growth and yield attributes of safflower during growing season of 2009-10 and 2010-11. The chemical fertilizers were applied at full (Urea 60 Kg ha-1 and DAP @ 30 Kg ha-1), half (Urea 30 Kg ha-1 and DAP 15 Kg ha-1) and quarter doses (Urea 15 Kg ha-1 and DAP 7.5 Kg ha-1). The PGPR (Azospirillum brasilense and Azotobacter vinelandii) were applied as seed inoculation @106cells/ml. Maximum plant height, number of branches/plant, leaf chlorophyll and leaf area was recorded in Azospirillum and Azotobacter with full dose of chemical fertilizers and with full dose of chemical fertilizers treatments alone while maximum number of capitulum/plant, capitulum weight and seed yield was shown by Azospirillum brasilense supplemented with half dose of chemical fertilizers. Maximum achene oil contents were recorded in Azospirillum treatment supplemented with half dose of chemical fertilizers and Azotobacter+full dose of chemical fertilizers. The PGPR improved plant growth and yield by reducing the use of chemical fertilizer (50 %), hence leading towards sustainable agriculture production.