The effects of some microbial fertilizers (BBDR and mycorrhiza) on the development and flower quality of marigold (Tagetes erecta L.)

This study was conducted on marigold flowers (Tagetes erecta L.) grown in an unheated greenhouse during the years 2021-2022. The effects of BBDR solutions consisting of different bacterial strains and mycorrhiza on the development of marigold flowers were determined in the study. Morphological, physiological, and phenological parameters were examined in the experiment. The averages of data collected during the vegetation process in May, June, July, August, and September were taken, and comparisons were made. Microbial fertilizer applications showed better results statistically compared to the control group in terms of plant height, plant diameter, flower height, flower diameter, flower yield, and root parameters. Among these, the 4th application stood out as the overall superior application. Results regarding leaf area and anthocyanin were generally considered insignificant, while the 4th application emerged as the superior application group in terms of chlorophyll accumulation. Additionally, all application groups differed from the control group in terms of the first flowering date, promoting early flowering. Based on the data, it was concluded that the applications of microbial fertilizers, either singly or in combination, led to significant differences in the growth parameters of plants, and the 4th application stood out as the superior one. Keywords: Marigold, PGPR, Mycorrhiza, Tagetes erecta