Author(s)

Monyck Jeane dos Santos Lopes¹, Moacyr Bernardino Dias Filho², Thomaz Henrique dos Reis Castro¹, Marta Cristina Corsi de Filippi³, Gisele Barata da Silva¹

¹Plant Protection Laboratory, Institute of Agricultural Sciences, Federal Rural University of Amazonia (UFRA), Belém, Brazil.
²Brazilian Agricultural Research Corporation (Embrapa), Belém, Brazil.
³Brazilian Agricultural Research Corporation (Embrapa), Goiania, Brazil.

The use of beneficial microorganisms in forage grasses is a potentially advantageous technique for a more sustainable pasture management by decreasing the need for chemical fertilization. Our aims were to determine the best method of microorganism inoculation on Brachiaria (Syn. Urochloa) brizantha cv. BRS Piata, compare the responses of inoculated plants of this forage grass with fertilized and unfertilized controls and examine its effect on some morphological, physiological and biochemical responses. On the first experiment, three inoculation methods were tested: in the seed, seed and soil, and soil, with Pseudomonas fluorescens (BRM-32111) and Burkholderia pyrrocinia (BRM-32113). In the second experiment, fertilized and unfertilized plants were either inoculated with BRM-32111, BRM-32113 and co-inoculated (BRM-32111 + BRM-32113). In a final experiment, B. brizantha was inoculated by soil drenching with BRM-32111, BRM-32113 and co-inoculated (BRM-32111 + BRM-32113), and compared to fertilized- and unfertilized-controls. The inoculation by soil drenching, at seedling stage, was more effective than inoculation only in the seed or both in the seed and by soil drenching. The fertilizer may have suppressed the beneficial bacterial effects on the growth of B. brizantha. P. fluorescens and B. pyrrocinia co-inoculated increased nitrate, protein, nitrogen concentration, Spad index (chlorophyll content), leaf area, number of tillers, net photosynthesis and total biomass production of B. brizantha plants. Our results point out to a potentially valuable source of practical information in the search of an eco-friendlier approach to increase pasture productivity.

Forage Grass, Rhizobacteria, Photosynthesis, Nitrate, Nitrogen

dos Santos Lopes, M. , Dias Filho, M. , dos Reis Castro, T. , de Filippi, M. and da Silva, G. (2018) Effect of Pseudomonas fluorescens and Burkholderia pyrrocinia on the Growth Improvement and Physiological Responses in Brachiaria brizantha. American Journal of Plant Sciences, 9, 250-265. doi: 10.4236/ajps.2018.92021.