SUMMARY
It has been determined in many research results that plant growth promoting rhizobacteria (PGPR) affect yield, plant growth and fruit quality and play an important role. However, the use of biostimulants in agricultural production in Malatya is negligible. In order to contribute to the region's producers, a research was planned directly in the producer's garden in the Malatya/Arguvan region, which is an important melon production center. A trial was established with Arguvan (Narmikan) melon type and Kirkagaç 637 melon cultivars, which are the most grown local cultivars in the summer period of plant growth-promoting rhizobacteria in irrigated and non-irrigated melon cultivation in Malatya-Arguvan conditions, and the trial was repeated for two consecutive years. In the research, Bacillus subtilis, Bacillus megatorium, Enterococcus spp. and cocktail bacteria solutions, which are a mixture of these three bacteria were used. Inoculation of bacteria into seeds was done by soaking the seeds in bacterial solution for 24 hours. The effects of the use of bacteria on the fruit quality of melon in cultivation with the method of seed sowing in the field were determined. In the study, the presented of which are resulted in fruit only pomological porperties ; fruit height, fruit weight, fruit flesh thickness, fruit shell thickness, fruit diameter, seed cavity diameter, pH and WTSS contents were examined, and two-year results were presented. The effects of different bacteria on the fruit pomological properties were not found statistically significant except for the TSS values of Kirkagaç 637 cultivars grown under non-irrigated conditions. The effects of different bacteria on the fruit pomological characteristics of Kirkagaç 637 melons grown under non-irrigated conditions were found statistically significant, although there were differences in other parameters, it was not statistically significant. Bacillus subtilis bacteria application has been the prominent bacterial application in terms of fruit characteristics.