Dâmiany Pádua Oliveira

Estirpes de Bradyrhizobium em simbiose com guandu‑anão em casa de vegetação e no campo

O objetivo deste trabalho foi avaliar a eficiencia simbiotica de estirpes de bacterias fixadoras de nitrogenio do genero Bradyrhizobium com guandu-anao. Os experimentos foram conduzidos em vasos de Leonard, em vasos com solo e em campo. Foram testadas 11 estirpes em vasos de Leonard, e as que apresentaram maior eficiencia em promover o crescimento do guandu-anao foram avaliadas em vasos com solo (Latossolo Vermelho-Amarelo e Cambissolo) e em campo (Latossolo Vermelho-Amarelo). Em todos os experimentos, os tratamentos foram comparados a dois controles positivos (estirpes aprovadas como inoculantes para as cultivares de guandu-anao BR 2003 e BR 2801) e a duas testemunhas sem inoculacao, uma com alta concentracao de N mineral, e a outra, a depender do experimento, sem N mineral (solo) ou com baixa concentracao de N (vasos de Leonard). Algumas estirpes proporcionaram crescimento vegetal semelhante ou superior as estirpes-referencia e as testemunhas em vaso de Leonard. Em vasos com solo, o tipo de solo influenciou os tratamentos. No campo, nao houve diferenca entre os tratamentos, e as estirpes nativas promoveram bom crescimento. O guandu-anao e capaz de estabelecer associacao simbiotica com bacterias fixadoras de N2, e a estirpe UFLA 03-320 apresenta potencial para ser recomendada para a cultura junto com a estirpe BR 2801.

Acid tolerant Rhizobium strains contribute to increasing the yield and profitability of common bean in tropical soils

Symbiosis of common bean with nitrogen-fixing bacteria can lead to a reduction in production costs and in environmental impacts. Considering the diversity of soils and climates, it is important to validate bacterial strains under different conditions to consolidate their recommendation as inoculants. Studies concerning the economic viability of Rhizobium inoculation in common bean are few, but they could assist in choosing the strain to be adopted. The aim of this study was to evaluate the performance of Rhizobium strains isolated from acid soils from the Amazon inoculated in seeds of the ‘BRSMG Madrepérola’ cultivar and to evaluate the economic viability of their use in the field. Four field experiments were conducted in the state of Minas Gerais, Brazil. A randomized block experimental design was used with four replications and seven treatments: inoculation with the strains CIAT 899 (Rhizobium tropici), UFLA 02-100 (R. etli), UFLA 02-68 (R. etli bv. mimosae), UFLA 02-127 (R. leguminosarum bv. phaseoli), and UFLA 04-173 (R. miluonense), plus two controls, one without inoculation + mineral nitrogen (N-urea) at a rate of 80 kg N ha-1 and another without inoculation and without mineral N. The strain CIAT 899 is already recommended for the manufacture of commercial inoculants, and the others, collected in the Amazon region, have proven to be highly effective in biological nitrogen fixation. Symbiosis of common bean with all the strains evaluated leads to satisfactory yields, with reduction in the application rate of mineral nitrogen and in environmental impacts and, consequently, reduction in economic costs, with higher profitability.

Agronomic efficiency of Rhizobium strains from the Amazon region in common bean

Para maximizar a contribuicao da fixacao biologica de nitrogenio no feijoeiro-comum e necessaria a utilizacao de estirpes de bacterias mais adaptadas, competitivas e eficientes no processo simbiotico. Nesse sentido, objetivou-se avaliar, em um Argissolo Vermelho Distrofico tipico do municipio de Formiga-MG, a eficiencia agronomica (EA) de tres estirpes isoladas de solos acidos e com alto teor de Al da Amazonia e comparar suas EA a da estirpe referencia CIAT 899T e a de dois controles sem inoculacao (um sem e outro com 80 kg ha-1 of N-ureia). Os resultados indicaram que a inoculacao com as estirpes UFLA 02-100 e UFLA 02-127 propicia rendimento de graos equivalente ao da estirpe referencia e ao do controle com N mineral e que por isso, ambas tem potencial para ser recomendadas como inoculantes para o feijoeiro-comum.

Viabilidade da inoculação líquida com Rhizobium etli no sulco de semeadura do feijoeiro-comum

The objective of this work was to evaluate the viability of liquid medium inoculation of Rhizobium etli in the planting furrow and to certify the efficiency of its strain UFLA 02-100 as a potential inoculant for common bean (Phaseolus vulgaris). The treatments consisted of three application rates of liquid inoculant applied in the planting furrows and one rate applied in common bean seed, besides two controls without inoculation. The inoculant contained 109 cells of Rhizobium etli mL-1. Regardless of the application method, the yield obtained with the inoculation was equivalent to that of N from urea; however, the application in the furrows, at 0.6 L ha-1, is more advantageous due to the operational practicality and reduced costs.

Rhizobium strains selected from the Amazon region increase the yield of snap bean genotypes in protected cultivation

A l though the use of inoculants containing rhizobia is encouraged, there are no official recommendations for inoculation of snap bean. In this respect, the aim of this study was to evaluate the agronomic performance of Rhizobium strains in symbiosis with snap bean cultivars with different growth habits and crop cycles. The experiment was carried out in pots with soil in a greenhouse in the spring-summer season in Lavras, state of Minas Gerais, Brazil. A completely randomized experimental design was used, with 4 replications, in a 4 × 7 factorial arrangement involving four snap bean cultivars and seven treatments – five strains of Rhizobium (UFLA 02-100, UFLA CROP PRODUCTION AND MANAGEMENT Note Rhizobium strains selected from the Amazon region increase the yield of snap bean genotypes in protected cultivation Dâmiany Pádua Oliveira1, Sindynara Ferreira2,3, Bruno Lima Soares1, Paulo Ademar Avelar Ferreira1,4, Augusto Ramalho de Morais5, Fatima Maria de Souza Moreira1*, Messias José Bastos de Andrade2 1.Universidade Federal de Lavras Departamento de Ciência do Solo Lavras (MG), Brazil. 2.Universidade Federal de Lavras Departamento de Agricultura Lavras (MG), Brazil. 3.Intituto Federal do Sul de Minas Inconfidentes (MG), Brazil. 4.Universidade Federal de Santa Maria Departamento de Ciência do Solo Santa Maria (RS), Brazil. 5.Universidade Federal de Lavras Departamento de Estatística Lavras (MG), Brazil. *Corresponding author: fmoreira@dcs.ufla.br Received: Apr. 4, 2017 – Accepted: Sept. 18, 2017 02-127, UFLA 04-173, CIAT 899, and PRF 81), plus two controls without inoculation (with and without 500 mg N-NH4NO3·dm –3). We conclude that: i) while genetic differences were observed among cultivars with respect to nodulating capacity, in all cases significant benefits were observed from BNF inoculation and ii) inoculation with selected strains of Rhizobium, as well as fertilization with mineral N, favors plant growth, snap bean yields, and accumulation of N in the pods and, therefore, can fully substitute nitrogen fertilization in snap bean grown under protected cultivation.