Evaluation of growth and yield of Solanum tuberosum L. cultivars due to application of Plant Growth Promoting Rhizobacteria (PGPRs) and Chemical Fertilizer in Aeroponic Culture System and Field Conditions: using exploratory factor analysis

The present study was conducted at the Research Farm and Greenhouse of Agricultural and Natural Resources Center of Ardabil during two successive years (2018-2019). For the aeroponic system an experiment was set up as factorial based on completely randomized design with three replicates. There were three experimental treatments viz: seedlings of three potato cultivars (Agria, Caeser, and Banba), chemical fertilizer (fertilizer application and no fertilizer application), and three bacterial combined inoculants (without inoculation as control, Pseudomonas putida, Azospirillum lipoferum, and Azetobacter chroococcum). In the second year, a trial was set up under field conditions as factorial based on RCBD (completely randomized block design) using two factors in three replications. These factors included mini-tubers of potato cultivars (Agria, Caeser and Banba) produced in aeroponic culture and PGPRs (without PGPRs and PGPRs inoculation including Pseudomonas, Azospirillum, and Azetobacter). The results of factor analysis based on studied traits in in the aeroponic culture experiment showed that in weight and number of mini tubers, number of stems, number of stolon increased by application of chemical fertilizer and plant height and stolon length due to biological fertilizer application. Among cultivars, cv. Banba showed the highest yield (number and weight of minitubers 162,1135 g,)  with chemical fertilizer application. According to the results of factor analysis of field experiment, the use of A. lipoferum significantly increased the number of tuber, tuber weight, number of stems and growth indices of total dry weight, tuber dry weight, crop growth rate, tuber growth rate and leaf area, and A. chroococcum had an increasing effect on plant height and number of stolon.In field experiment, the highest yield (number and weight of tuber were 24,800 g,) according to traits and growth indices in Agria cultivar with application of A. lipoferum bacteria. Based on the current research findings, chemical fertilizers application in aeroponic cultivation and treating with A. lipoferum in field improve potato yield.