SUMMARY
This study was carried out to determine the effects of plant growth-promoting rhizobacteria and mycorrhiza treatments on the development of Zinnia elegans L. ‘Zesty’ and Dahlia variabilis L. ‘Figaro Violet’ cultivars. In the study, a suspension was first prepared from bacterial isolates developed at 25±2 °C for 24 hours. The prepared suspensions were adjusted to an absorbance value of 0,3 at 600 nanometers in a spectrophotometer. D. variabilis seedlings were immersed in suspensions prepared from ZE-12, ZE-13 and ZE-12+ZE-13, Z. elegans seedlings were immersed in suspensions prepared from ZE-2, ZE-7, ZE-12, ZE-13, ZE-12+ZE-13 for 30 minutes. In addition, Z. elegans seedlings were kept in mycorrhiza prepared at a concentration of 5000 ppm for 10 seconds. At the end of the period, flower seedlings were planted in pots with a mixture of peat and perlite. As the control group, seedlings without rhizobacteria and mycorrhiza treatment were used in both cultivars. The experiment was established with 3 replications and 10 plants per replication. The applications made in the D. variabilis experiment remained the same as the control in all other parameters except root dry weight. ZE-13 application was effective on root dry weight. It was determined that the applications made in Z. elegans seedlings increased the flower stem thickness and the number of leaves, especially the ZE-13 application was the most effective application. In conclusion, with this study, it was revealed that rhizobacteria and mycorrhiza applications, which are of natural origin and do not harm the environment, have the potential to be used in ornamental plants cultivation, and that these applications should be expanded.