The Restriction of Individual Performance of PGPR on Maize Nutrient Uptake by Antagonistic Relations

Abstract

Abstract Recent studies have shown that certain soil microorganisms are capable to sustain plant nutrition in both conventional and organic agriculture; however, yet further studies needed for evaluation of the factors affecting PGPR performance. The goal of this research was to evaluate performance of natural bacteria relative to nutrient uptake and biomass development in corn (Zea mays L.) as it is related to conventional production systems. Soils have been collected from forested areas of Lake Region. The isolated bacteria have been tested at the conventional farm in Mediterranean region. Nine isolated and one cocktailed bacteria suspensions have been applied to rhizosphere of corn plants under regular cultivation practices in conventional production systems. The results revealed that all isolates are showing either positive or negative effect on both plant performance and nutrient uptake. No statistical differences were observed on grain yield; however, Isolates 3 and 9 showed improved grain-excluded biomass performances by 37.1% and 38.5% respectively. Phosphorus, zinc and manganese uptakes were the highest in Isolate 6 whereas the highest Fe uptake was determined in Isolate 8 at the tuft formation stage. Although all isolates represent their specific individual performances as far as any plant nutrient uptakes are concerned, their cocktail was not as effective. That happened probably due to competition between the isolates.