Growth Promotion by Azospirillum brasilense in the Germination of Rice, Oat, Brachiaria and Quinoa

Abstract

Aims: The inoculation with growth promoting bacteria in cultivated crops is an alternative to reduce the use of chemical compounds minimizing environmental damage and production costs. According to outstanding benefits associated with low researches with the crops in question, the objective of the present work was to evaluate the characteristics of the development of Oryza sativa, Avena sativa, Brachiaria 75 ruziziensis and Chenopodium quinoa inoculated with growth promoting bacteria Azospirillum brasilense. Study Design:  The experimental design was completely randomized in a 4 x 4 factorial scheme with four replicates of 50 seeds. Place and Duration of Study: The experiment was conducted in a greenhouse, located at the Experimental Station of Horticulture and protected cultivation of the State University of Western Paraná at Marechal Candido Rondon city, 54º22’ W and 24º46’ S, and altitude of 420 m. Methodology: At greenhouse, the species were inoculated with Azospirillum brasilense then sowed in autoclaved sand forming the following treatments: no inoculation, seed inoculation, foliar inoculation, foliar and seed inoculation. At seven days after sowing, the germination percentage was evaluated and at 21 days after emergence the morphological characteristics of the crop. Results: The inoculation with bacteria favored seed germination of quinoa. However, for the crops of vetch and brachiaria, the statistic results of fresh weight accumulation were superior when inoculated. Some of the evaluated variables showed possible negative effects of inoculation, but these may be associated to the crops being sowed in an inert material, without the presence of necessary nutrients to plant development, such as nitrogen, which is an essential factor to obtain good results with the A. brasilense application. Conclusion: For the quinoa culture the seed inoculation favored germination, increasing it by 17%, a result considered promising, even if the differences were not maintained throughout the seedling development.