Effect of some PGPR (Plant Growth Promoting Bacteria) combinations on some soil properties and horticultural characteristics in Albion and Monterey strawberry cultivars

Strawberry is a temperate fruit specie grown all year round in both open and protected cultivation around the world and consumed with pleasure by consumers for its extraordinary appearance and rich taste and aroma. Like other berries, strawberries are highly suitable for environmentally friendly treatments and benefits greatly from these practices. The aim of this study is to reveal the effects of bacterial combination applications on soil properties, plant growth, and fruit content in Albion and Monterey strawberry varieties grown in open-field conditions in Erzurum province, Türkiye. The study included 5 groups: 4 different formulations (single, double, triple, and quadruple combinations) and a control group (without application). In this study, F1 (Rhizobium sp.), F2 (Priestia megaterium + Pseudomonas chlororaphis), F3 (Pseudomonas chlororaphis + Bacillus pumilus + Acinetobacter genospecies) and F4 (Bacillus safensis + Pseudomonas alcaligenes + Bacillus pumilus + Priestia megaterium) bacterial combinations were applied. In the experimental design, a total of 180 plants (2 × 5x18) were used, with 18 plants in each group, and Duncan's multiple range test was performed. The results of the two-year study showed that bacterial combination applications had a statistically significant effect on soil properties, plant morphology, fruit pomological traits, fruit chemical and bioactive content, and yield. When years and cultivars were evaluated together, the highest increase in yield compared to the control group was 72.5% with the F4 application, followed by F3 (62.3%), F1 (30.3%), and F2 (30%). When cultivars and applications were evaluated together, the average yield in the first year of the study was 176.04 g, while the average yield in the second year of the study was determined to be 227.03 g. When years and applications were evaluated together, the Albion strawberry cultivar had an average yield of 157.97 g, while the Monterey strawberry cultivar had an average yield of 245.09 g. Among bacterial combination, F3 and F4 found to be more effective for sustainable strawberry production in particular to obtain high yield and more health fruits.