Improving sweet corn (Zea mays L. var saccharata) growth and yield using Pseudomonas fluorescens inoculation under varied watering regimes

Plant growth promoting rhizobacteria (PGPR) such as Pseudomonas can support plant growth under water stressed conditions. In this study, the effects of four strains of Pseudomonas fluorescens on growth and yield of sweet corn (Zea mays L. var saccharata) were evaluated under various watering regimes. The experiment was a split plot, randomized complete block design at Marvdasht, Fars Province, Iran, during 2016 and 2017. The main factor was irrigation at 100% (I-100 no stress), 80% (I-80), and 60% (I-60) of plant requirement and the sub factor was bacteria inoculation at five levels: P. fluorescens P-1, P. fluorescens P-3, P. fluorescens P-8, P. fluorescens P-14, and no inoculation. The results showed that the watering regime at I-60 decreased row number per ear, seed number per row, and seed number per ear. Also, thousand-seed weight led to less canned seed yield, ear yield, and biological yield in both years. Root length and dry weight were also reduced by I-60 watering. Inoculation with P. fluorescens strains increased water deficit stress tolerance, root growth, and yield components. In this regard, strains P-1 and P-8 were most effective. The difference between the effectiveness of strains probability is related to ability to solubilize phosphate and siderophore production.