Hormonal imbalance triggered by rhizobacteria enhance nutrient use efficiency and biomass in oil palm

Abstract

A bacterial isolate was investigated for its application in growth promotion of the palm plants seedlings (Elaeis guineensis Jacq.) in the nursery. The isolate was identified as Bacillus amyloliquefaciens UFRAB01 by sequencing of the 16S rDNA gene. The hormone stimulus strain increased by 66% Indole-Acetic Acid (IAA), 44% Abscisic Acid (ABA), as well as increased macro and micronutrients content per plant. In the inoculated plants there was a 24% reduction in 1-Aminocyclopropane-1-Carboxylic Acid (ACC) levels. Inoculation promoted plant growth by increasing shoot dry matter by 110%, 123% root dry matter, 39% plant height and 19% stem diameter (SD), as well as the Dickson quality index (IQD), all in comparison to the control plant. The results of this work reveal that the use of plant growth-promoting rhizobacteria (PGPR) is able to alter the hormonal balance of the plant, increase the growth rates, as well as reduce chemical fertilizer use in palm oil plants by 50%.The improvement in the morphophysiological performance induces precocity, reducing the formation time of the seedlings in two months and the costs of production by reducing the use of chemical fertilization in the nursery period. The strain B. amyloliquefaciens UFRAB01 has the potential to promote the growth of palm oil plants.