TITLE:
Effect of Pseudomonas fluorescens and Burkholderia pyrrocinia on the Growth Improvement and Physiological Responses in Brachiaria brizantha
AUTHORS:
Monyck Jeane dos Santos Lopes, Moacyr Bernardino Dias Filho, Thomaz Henrique dos Reis Castro, Marta Cristina Corsi de Filippi, Gisele Barata da Silva
KEYWORDS:
Forage Grass, Rhizobacteria, Photosynthesis, Nitrate, Nitrogen
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.2,
January
26,
2018
ABSTRACT: 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.