This is the first report on the effect of light intensity and plant growth-promoting rhizobacteria (PGPR) on the growth of a tropical forage grass, being a relevant study to improve pasture management in conventional farming and integrated crop-livestock-forestry systems. In this study, our aim was to evaluate the effects of light intensity and Burkholderia pyrrocinia and Pseudomonas fluorescens inoculation on Brachiaria brizantha cv. BRS Piat~a growth, and phenotypic plasticity to shade. The experiment was conducted in a semi-controlled environment. Seedlings of B. brizantha were allocated to full sun and shade. P. fluorescens and B. pyrrocinia were inoculated individually or co-inoculated by soil drench, 14 days after seedling emergence. We evaluated morphogenesis, structural and growth parameters. Irrespective of the light regime, co-inoculated plants had greater leaf area and SPAD index (chlorophyll content). Increase in total biomass production in co-inoculated plants was over 100% and 300%, under full sun and shade respectively. Co-inoculated P. fluorescens and B. pyrrocinia increased shade tolerance in B. brizantha, improving plant performance. Co-inoculation promoted growth in B. brizantha under both sun and shade, indicating its potential as a bio-fertilizer in
onventional and integrated systems, especially in silvopastoral systems, where light availability to pasture growth may be limited.

LOPES, M. J. dos S.; DIAS-FILHO, M. B.; CASTRO, T. H. R.; SILVA, G. B. Light and plant growth-promoting rhizobacteria effects on Brachiaria brizantha growth and phenotypic plasticity to shade, Grass Forage Sci.73:493–499, 2018