Nutrients Uptake in Shoots and Biomass Yields and Roots and Nutritive Value of Zuri Guinea Grass Inoculated with Plant Growth-promoting Bacteria

ABSTRACT

The objective of this study was to evaluate the effects of plant growth promoting bacteria (PGPB) inoculation in Zuri guinea grass [Megathyrsus (syn. Panicum) maximus] on shoot dry weight (SDW) and root dry weight (RDW) yield, morphological compositions, number of tillers, and nutrients concentrations in SDW. The experiment was carried out under greenhouse conditions in a randomized block design consisting of eight treatments with five replicates. The inoculation with the Ab-V5 and Ab-V6 strains of Azospirillum brasilense and Pseudomonas fluorescens or co-inoculation with Rhizobium tropici and Ab-V6, with nitrogen (N) fertilization, as well as re-inoculations of the plants after cuttings were taken were evaluated. The plant growth-promoting bacteria and N fertilization promoted increases in SDW and RDW yield, tillers dry weight, relative chlorophyll index (RCI) and nutrients uptake in shoots of Zuri guinea grass. There were effects of re-inoculation the PGPB by P. fluorescens in shoots, N, magnesium (Mg) and boron (B) concentration in SDW.

KEYWORDS:

• Azospirillum brasilense
• megathyrsus maximus
• pseudomonas fluorescens
• rhizobium tropici
• tropical grass
• nitrogen biological fixation
• diazotrophic bacteria

Acknowledgments

We would like to thank the Laboratory of Biotechnology of EMBRAPA Soja for providing the bacteria, the Foundation for Research Support of the State of São Paulo Process FAPESP Grant #2017/17573-4 for financial aid to support this research for the support in conducting this work and for stock exchange financing (Process Grant #2017/26364-0).