RHIZOBIUM INOCULATION IN DRY BEAN CV. BRSMG MADREPÉROLA SUBJECTED TO FUNGICIDE SEED TREATMENT

Authors

B. E.S. Cardillo, Universidade Federal de Lavras
D. P. Oliveira, Universidade Federal de Lavras
B. L. Soares, Universidade Federal de Lavras
F. A.D. Martins, Empresa de Pesquisa Agropecuária de Minas GeraisFollow
G. G. Ferreira Neto, Universidade Federal de Lavras
J. C. Costa
F. M.S. Moreira, Universidade Federal de Lavras
M. J.B. Andrade, Universidade Federal de Lavras

Document Type

Article

Date of this Version

3-2017

Citation

ANNUAL REPORT OF THE BEAN IMPROVEMENT COOPERATIVE, No. 60, March 2017. Published by USDA.

Comments

U.S. government work.

Abstract

INTRODUCTION: Fungicide seed treatment is an important strategy for plant pathogen control in the dry bean crop. However, there are reports that it may hinder biological nitrogen fixation (BNF). The present study was carried out for the purpose of verifying the compatibility of fungicide treatment and BNF, so as to assist producers in making decisions in regard to selection of products with the least impact on biological processes and, consequently, on yield.

MATERIALS AND METHODS: A field experiment was carried out in the 2014 dry season in a Latossolo Vermelho distroférrico típico in the municipality of Lavras, MG, Brazil. There was no record of inoculation prior to the dry bean crop in the area, and the population of native rhizobia capable of nodulating dry bean was approximately 10³ colony forming units per gram of soil. The statistical design used was randomized blocks with three replications and a (5×3) + 1 factorial arrangement, involving five fungicides in seed treatment (Captan, Carboxin + Thiram, Difenoconazole, Fluazinam + Thiophanate-methyl, and Fludioxonil + Metalaxyl-M, all at application rates recommended by the manufacturers) and three levels of inoculation (without inoculation, seed inoculation, and inoculation in the planting furrow), plus an additional treatment with 80 kg ha^-1 of N (40 kg ha^-1 N at sowing + 40 kg ha^-1 N at topdressin inoculant containing ±10⁹ viable cells of the strain CIAT 899 (Rhizobium tropici) per mL was applied at the rates of 40 mL kg-1 on seeds or 300 mL ha-1 in the planting furrow. Seed inoculation occurred one hour before sowing. Sowing was manual, at a density of 15 seeds per meter. The cultivar BRSMG Madrepérola was used, with high yield potential and good level of resistance to the main diseases that occur in Minas Gerais. Plants are prostrate, of type III growth habit, with low tolerance to lodging (CARNEIRO et al., 2012). Distribution of the inoculant in the furrow was performed after sowing with the aid of a manual backpack sprayer, and the spray volume was equivalent to 20 L ha^-1.