Pre-Inoculation with Bradyrhizobium spp. in Industrially Treated Soybean Seeds (original) (raw)
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African Journal of Agricultural Research, 2018
The competitiveness of Brazilian soybean in the international market is highly dependent on biological nitrogen fixation, whose efficiency is related to factors that affect the survival of the bacteria, such as the chemicals used in the treatment of seeds. The study objective was to evaluate Bradyrhizobium preinoculation (10 days before sowing) of soybean seeds treated with fungicides and insecticide compared to the standard inoculation performed on the planting day. Four experiments were conducted in two distinct ecosystems, two in Brazilian savanna (Cerrado) and two in Cerrado/forest transition areas of Roraima state. In each ecosystem, the experiments were performed in areas without and with soybean cultivation history. The treatments were in: 1-Control without inoculation; 2-inoculation on sowing day in untreated seeds; 3-treatment with carbendazim; 4-treatment with pyraclostrobin + methyl thiophanate + fipronil; 5-treatment with fludioxonil + metalaxyl-M. Groups 3, 4, and 5 were preinoculated 10 days before sowing. Viable cells in the seeds were recovered on the sowing day. Nodule number and dry mass, root, and aerial part dry mass were evaluated 35 days after emergence. Grain yield was evaluated at harvest. The number of viable cells was negatively affected by seed treatment. For all evaluated variables, treatments with pre-inoculation plus fungicides/insecticide were similar to the standard sowing-day inoculation. Pre-inoculation performed 10 days before planting, along with seed treatment with fungicides/insecticides, positively affected soybean crop productivity and could be used without compromising the nitrogen fixation.
Efficiency of pre-inoculation of soybeans with Bradyrhizobium up to 60 days before sowing
African Journal of Agricultural Research, 2018
The inoculation of nitrogen-fixing bacteria in soybean crops allows the achievement of high crop yield by reducing or eliminating the application of nitrogen fertilizers. Pre-inoculation of seeds can reduce costs and increase the efficacy of this agricultural practice. The objective of this study was to assess the efficacy of pre-inoculation of soybean seeds with a commercial inoculant of Bradyrhizobium (RIZOLIQ LLI ® manufactured by Rizobacter do Brasil) at 60, 45, and 30 days before sowing using a cell protector and different chemical treatments. The study was conducted in four municipalities in the state of Paraná (Londrina, Pato Branco, Ponta Grossa, and Santa Tereza do Oeste) and included 14 treatments, a negative control, standard inoculation of the recommended bacterial strains on the day of sowing, and pre-inoculation at 30, 45, and 60 days before sowing using the commercial inoculant RIZOLIQ LLI ® together with the cell protector and chemical treatment of seeds with Imidacloprid (Rocks ®), Fipronil+Thiophanate-methyl+Pyraclostrobin+ (Standack ® Top), Metalaxyl-M+Fludioxonil (Maxim ® XL), and Metalaxyl-M+Fludioxonil+Thiabendazole with Thiamethoxam (Maxim ® Advanced+Cruiser ®). The nodulation, plant biomass, nitrogen concentration in shoot and grain, and grain yield were evaluated. The cell protector was efficient in maintaining the bacterial inoculant viable in the seed for up to 60 days. All treatments of pre-inoculation of soybean chemically-treated seeds up to 60 days before sowing could be performed without impairment of nodulation, plant biomass, nitrogen concentration in shoot and grain, and grain yield. Therefore, pre-inoculation of soybean seeds up to 60 days before sowing is an efficient and practical inoculation strategy for sowing soybean crops.
Pesquisa Agropecuária Tropical, 2018
Nitrogen fertilization may interfere in the quality of soybean seeds. This study aimed to determine the physiological and sanitary quality of soybean seeds, in response to levels and times of nitrogen (N) application associated with Bradyrhizobium japonicum inoculation. Treatments were arranged in a randomized block design, in a 2 × 3 × 4 factorial arrangement [two soybean cultivars (BRS 1074 IPRO and ST 797 IPRO), three application times (sowing, 30 and 50 days after emergence) and four N levels (0 kg ha-1 , 20 kg ha-1 , 40 kg ha-1 and 60 kg ha-1), with four replicates. The 1,000-seed mass, moisture content, germination rate, seedling height, shoot length, primary root length, total seedling dry matter, electrical conductivity, mechanical damage, vigor and viability (tetrazolium test) and sanitary quality of the seeds were measured. The use of mineral N, associated with the inoculation of B. japonicum bacteria, does not prove to be consistent, in terms of its effects on the physiological quality of soybean seeds, although the incidence of pathogens may be reduced.
In-furrow inoculation of soybean as alternative to fungicide and micronutrient seed treatment
Revista Brasileira de …, 2010
A soja é a principal cultura de grãos do Brasil e pode se beneficiar fortemente da inoculação com estirpes selecionadas de Bradyrhizobium. Contudo, a incompatibilidade entre inoculantes e o tratamento de sementes com fungicidas e micronutrientes representa um fator limitante para alcançar taxas elevadas de fixação biológica do N. Desse modo, práticas de inoculação que possam minimizar os efeitos negativos desses produtos devem ser procuradas, e a inoculação no sulco aparece como uma alternativa atraente. Este estudo relata o resultado de sete experimentos de campo conduzidos no Brasil por três safras: três em solos previamente cultivados com soja (> 104 células g-1 de solo de Bradyrhizobium) e quatro em áreas cultivadas pela primeira vez (< 102 células células g-1 de solo de Bradyrhizobium). A compatibilidade com fungicidas e micronutrientes foi comparada com as sementes inoculadas com inoculantes turfosos ou líquidos, ou recebendo diferentes doses de inoculante líquido no sulco. Em áreas com populações estabelecidas de Bradyrhizobium, em geral, os agrotóxicos aplicados nas sementes não alteraram a nodulação, mas também não beneficiaram os rendimentos, enquanto a inoculação sempre incrementou o N acumulado nos grãos ou o rendimento, e o N-fertilizante diminuiu tanto a nodulação como o rendimento. Em áreas cultivadas pela primeira vez, o tratamento com o fungicida alterou a nodulação quando aplicado em conjunto com inoculante turfoso ou líquido nas sementes. A inoculação no sulco diminuiu o efeito deletério dos tratamentos das sementes, e os melhores desempenhos foram obtidos com altas concentrações de células de Bradyrhizobium, de até 2,5 milhões de células semente-1.
African Journal of Agricultural Research, 2015
Recent studies in the Nawa region of Côte d’Ivoire have indicated an acute malnutrition rate of 11.3% among cocoa producers. One of recommended actions from the studies was to diversify agriculture with nutrients rich crops. Introduction of soybean (Glycine max) cropping system could go a long way to ensure food and nutritional security in the region. The current study was conducted in two sites (Logboayo and Soubré) in the south-west of Côte d’Ivoire, to evaluate the effect of IRAT-FA3 Bradyrhizobium japonicum strain inoculum on the agronomic performance of five varieties of soybean named Doko, Canarana, V3_2013, V6_2013 and IT_235. The experimental design was randomized complete block with a split plot with inoculation as the main factor and variety of soybean as subplot treatment replicated three times. Data were collected on some yield parameters and the grain yield. Results of yield showed a highly significant effect (P<0.0001) of the site and a significant effect (P=0.0316) of the variety x treatment interaction. Highest yield was recorded at Logboayo with 1838 kg ha-1 compared to 1220 kg ha-1 for Soubré. The variety V6_2013 with a yield of 1931 kg ha-1 and good vegetative development could be recommended as elite variety for the farmers in the Nawa region.
Pesquisa Agropecuária Tropical
In early soybean cultivars of high productive potential, the use of chemical nitrogen (N) fertilizer may be a critical factor to meet the crop N requirements for obtaining high yields. In order to determine the response of early soybean cultivars to doses and times of nitrogen fertilizer application, associated with the inoculation of Bradyrhizobium japonicum, two field experiments were conducted in a Quartzipsamment soil from the Brazilian tropical Savannah, during the 2016/2017 and 2017/2018 growing seasons. The experimental treatments were arranged in a 2 × 3 × 4 factorial scheme, being two soybean cultivars (BRS 1074 IPRO and ST 797 IPRO), three application times of N fertilizer (sowing, 30 and 50 days after the emergence) and four N doses (0 kg ha-1, 20 kg ha-1, 40 kg ha-1 and 60 kg ha-1). The following variables were evaluated: plant height, shoot dry matter, number of nodules, nodule dry matter, first pod height, number of pods, number of grains per pod, 1,000-grain mass, gra...
Semina: Ciências Agrárias, 2017
Given the high costs of agricultural production, especially due to the price of fertilisers, particularly nitrogen, the use of inoculants to supply nitrogen to soybean crops is a widely recommended practice. The objective of this study was to evaluate the feasibility of applying inoculants through seed and planting furrow in soil previously cultivated with soybean and Brazilian native “cerrado” biome soil under greenhouse conditions. Seven treatments were tested: 1) inoculation via seed (inoculant + fungicide + micronutrient), 2) treatment via seed (fungicide + micronutrient), 3) control (only seed), 4) inoculation via furrow-dose 1 (recommended dose), 5) inoculation via furrow-dose 2 (twice the recommended dose), 6) inoculation via furrow-dose 3 (three times the recommended dose) and 7) inoculation via furrow-dose 1 + seed inoculation. We evaluated plant height, fresh and dry matter weight of the aerial part and nodules, number of total, viable and non-viable nodules, number of pod...
Journal of Agricultural Science
Pre-inoculating soybean seeds can make sowing faster and provide additional benefits to farmers. However, it needs to guarantee the nitrogen supply to maintain the viability and sustainability of the technique. In this study, we evaluated the agronomic efficiency of SIGNUM® inoculant in the pre-inoculation at 20 and 35 days before sowing chemically treated soybean seeds. Experiments were conducted in four field experiments located at Paraná, Brazil, with a history of soybean cultivation managed under no-tillage systems, with crop rotation according to regional edaphoclimatic conditions. Agronomic efficiency in fields were compared with standard inoculation with a registered product used by farmers. Chemical treatment of soybean seeds with Standak Top® or Maxin XL® + Cruiser® associated with pre-inoculation of the inoculant SIGNUM® for 25 and 30 days reduced the concentration of viable Bradyrhizobium cells recovered from seeds. However, no significant difference was observed regardin...