Nine strains of Pseudomonas fluorescens and P. putida: Effects on growth indices, seed and yield production of Carthamus tinctorius L.

To study the effects of growth promoting bacteria, Pseudomonas spp. on the yield production and some of the vegetative growth traits of the medicinal plant, Carthamus tinctorius variety IL111, an experiment was carried out on the Research Farm of Ilam University. The experiment was laid out in a completely randomized block design (CRBD) with three replications. The treatments included the inoculation of seeds with strains 36, 99, 169 and 187 of Pseudomonas fluorescens as well as strains 168, 177, 159, 11 and 41 of Pseudomonas putida bacteria along with the non-inoculated treatment (control). In every experimental plot with 18 m²; area, the inoculated seeds with bacteria were planted in six with an intra-row spacing of 15 cm. The results indicated that from 16 measured traits respecting the vegetative and yield production traits in the safflower plant, seven traits were affected by the treatment of bacteria which included stem diameter, number of primary branches in plants, index of leaf area, plant dry biomass, crop growth rate, seed oil percentage and the weight of 1000 seeds. These traits were superior in the plants inoculated with PGPR bacteria. The efficiency of P. putida bacteria was superior to P. fluorescens and the control. Totally the strains 177 and 11 of P. putida had the best vegetative and yield production in terms of the mentioned traits in safflower plant. The application of biological fertilizers (growth promoting bacteria) demonstrated ability to improve the growth characteristics of this plant.