A inoculação com microrganismos afeta positivamente a arquitetura do sistema radicular e o acúmulo de nutrientes em mudas de Euterpe oleracea (Mart.).

Abstract

Açaizeiro (Euterpe oleracea) has great economic importance due to the volume of production, exports and consumption, which are on a large scale, compromised by the slow initial growth of seedlings and the high sensitivity to water deficit. The inoculation of growth promoting microrganisms induces changes in the architecture of the root system (ARS) resulting in greater nutritional accumulation with a consequente increase in biomass. The aim was to evaluate how the microrganisms changed the ASR and the accumulation of nutrientes and biomass in açaizeiro seedlings. The treatments consisted of individual inoculation, in the roots of the seedlings, of tow rhizobacteria (Burkholderia pyrrocinia – BRM-32113 and Bacillus subtilis – UFRA-92), four fungal isolates of Trichoderma asperellum (UFRAT-06, T-09, T-12 and T-52) applied in mixture and a control (no inoculated). Seedlings inoculated with T. asperellum showed greater increases in the number of root tips and side branches and at five months of age, all seedlings inoculated showed a higher proportion of thick roots. The accumulation and the efficiency in the use of nutrientes were higher in seedlings inoculated with T. asperellum, which showed greater accumulation of biomass with na increase of 85% in the height of the seedling, 204% in the diameter of the collection, 39% in the number of leaves and showed characteristics required by the morphological standard of the State Commission for Seeds and Seedlings of Pará (SCSS-PA) and at five months they were ready for establishment in the field, with na early gain of three months. In this sense, inoculation with microrganisms, especially T. asperellum, changed the morphological characteristics of the aerial part promoting a considerable increase in growth parameters. More studies are needed to understand how microrganisms influence the physiological and metabolic characteristics that may have contributed to the early growth and development of Young açaizeiros.