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MANEJO NUTRICIONAL, QUÍMICO E BIOLÓGICO DE HETERODERA GLYCINES E PRATYLENCHUS BRACHYURUS NA CULTURA DA SOJA

Wed, 24 Jun 2026 00:00:00 GMT

Título: MANEJO NUTRICIONAL, QUÍMICO E BIOLÓGICO DE HETERODERA GLYCINES E PRATYLENCHUS BRACHYURUS NA CULTURA DA SOJA Autor(es): Rocha, Marcos Vinícios Ferreira Primeiro Orientador: Alves, Gleina Costa Silva Primeiro Membro da Banca: Souza, Flivia Fernandes de Jesus Segundo Membro da Banca: Conceschi, Thaís Fernandes de Jesus Abstract: Soybean (*Glycine max* L.) is a major crop in Brazilian agribusiness, frequently affected by plant-parasitic nematodes—notably *Heterodera glycines* and *Pratylenchus brachyurus*—which cause significant yield losses. In this context, this study aimed to evaluate the effect of different rates of boron (B) and copper (Cu) on the population dynamics of these nematodes, as well as on soybean yield and economic viability. The experiment was conducted in Urutaí, Goiás (GO), using a randomized complete block design with 18 treatments and four replications. Treatments included soil-applied B, foliar-applied Cu, and chemical and biological standards, alongside an untreated control. Nematode assessments were performed at 30 and 60 days after emergence (DAE). Results indicated numerical variations in *H. glycines* and *P. brachyurus* populations in treatments with higher boron rates, whether applied alone or in combination with copper. Additionally, numerical variations were observed in the number of non-viable cysts in the soil in treatments combining the two micronutrients. However, the differences observed among treatments were not statistically significant according to Tukey's test (p < 0.05). Crop yield was limited by severe water deficit conditions lasting approximately 40 days of the growing season, compounded by potential phytotoxicity from the higher micronutrient rates, resulting in low yields across all experimental plots. Thus, the results suggest that nutritional management with boron and copper may be associated with numerical variations in nematode population dynamics, although no control effect was demonstrated under the conditions of this study. Further studies are recommended—preferably in controlled environments and under diverse field conditions—to evaluate intermediate rates and investigate the potential relationship between plant nutritional status, nematode population dynamics, and crop physiological stability. Editor: Instituto Federal Goiano Tipo: Dissertação

INTEGRAÇÃO DO CONTROLE GENÉTICO, QUÍMICO E BIOLÓGICO NO MANEJO DE NEMATOIDES NA CULTURA DA SOJA (Glycine max L. Merril)

Thu, 07 May 2026 00:00:00 GMT

Título: INTEGRAÇÃO DO CONTROLE GENÉTICO, QUÍMICO E BIOLÓGICO NO MANEJO DE NEMATOIDES NA CULTURA DA SOJA (Glycine max L. Merril) Autor(es): Hamer, Chaenzy Specimille Primeiro Orientador: Araujo, Fernando Godinho de Primeiro Membro da Banca: Araujo, Fernando Godinho de Segundo Membro da Banca: Silva, Monique Thiara Rodrigues e Terceiro Membro da Banca: Moreira, Janaina Alves de Almeida Abstract: Soybean (Glycine max L.) cultivation is among the main commodities for the world and Brazilian agricultural economy, and its productivity can be reduced by attacks from various nematode species. In order to understand the efficiency of different management strategies, this study aimed to evaluate the integration of genetic, chemical, and biological control in the management of root-knot nematodes (Meloidogyne javanica) and soybean cyst nematodes (Heterodera glycines) in soybean crop, highlighting the benefits of each control within integrated management. The trial was conducted in a commercial field in the western region of Bahia, in a randomized block design with a 2 x 15 factorial scheme (2 cultivars x 15 treatments), with four replications. The treatments considered were the active ingredients Fluopyram and Cyclobutrifluram, the fungal biological agents Purpureocillium lilacinus and Pochonia chlamydosporia, and the bacterium Bacillus velezensis. For soybean cultivars, a material without nematode resistance (Brasmax Olimpo IPRO) and one moderately resistant to M. incognita, H. glycines races 6, 9, 10, 14, and 14+, in addition to having resistance to race 3 (NEO 840 IPRO), were adopted. To estimate the effects of the treatments on the two soybean cultivars, phytotoxicity, plant stand, root length, shoot fresh weight (SFW), number of nematodes in the roots, number of nematodes in the soil, and crop productivity were evaluated. The active ingredient Fluopyram, applied via seed treatment, caused initial phytotoxicity in soybean crop, however, the symptoms were significantly reduced when combined with biological control. This phytotoxicity did not affect the development of the soybean shoots. The evaluated cultivars showed genetic differences for quantitative characteristics, with the Brasmax Olimpo IPRO cultivar presenting a higher initial stand and a more developed root system, while the NEO 840 IPRO cultivar showed better performance in the shoot fresh mass variable at 75 DAE (days after emergence). The NEO 840 IPRO cultivar showed lower multiplication of M. javanica and H. glycines, impacting better productivity. Genetic control proved to be the basis of management, being the main factor responsible for the reduction in the nematode population in the trial conducted. However, in the absence of resistance, all treatments evaluated promoted a reduction in the nematode population compared to the control at 75 DAE. The isolated application of chemical or biological products provided a numerical increase in productivity of up to 22.87% in the NEO 840 IPRO cultivar and up to 86.35% in the Brasmax Olimpo IPRO cultivar. The integration of biological and chemical management provided greater numerical increases in productivity compared to the isolated application of each method, with the combination of Bacillus velezensis, applied in seed treatment, and Fluopyram, via planting furrow, providing a numerical increase of 49.51% in the NEO 840 IPRO cultivar, and the combination of Bacillus velezensis and Cyclobutrifluram, applied in seed treatment, providing a numerical increase of 114.48% in the Brasmax Olimpo IPRO cultivar. Integrated management, combining genetic resistance, chemical and biological nematicides, showed the greatest productivity gains for soybean cultivation. Editor: Instituto Federal Goiano Tipo: Dissertação

SENSIBILIDADE DE ISOLADOS DE Fusarium spp. CAUSADORES DA SÍNDROME DA MORTE SÚBITA DA SOJA À MISTURA FLUXAPIROXADE + PIRACLOSTROBINA

Wed, 01 Apr 2026 00:00:00 GMT

Título: SENSIBILIDADE DE ISOLADOS DE Fusarium spp. CAUSADORES DA SÍNDROME DA MORTE SÚBITA DA SOJA À MISTURA FLUXAPIROXADE + PIRACLOSTROBINA Autor(es): Lima, Milton Luiz da Paz Primeiro Orientador: Gonçalves, Debora Janine Silva Abstract: Soybean sudden death syndrome, caused by Fusarium species, represents one of the major phytosanitary challenges affecting the crop. This study aimed to characterize Fusarium spp. isolates regarding their sensitivity to the fluxapyroxad + pyraclostrobin mixture by evaluating mycelial growth, area under the mycelial growth progress curve (AUMGPC), mycelial growth rate (MGR), and EC50. A total of 44 isolates collected from Goiás State, Brazil, were analyzed. The results revealed high phenotypic variability, with a predominance of sensitive isolates, along with the presence of moderately sensitive and insensitive subpopulations, indicating an early shift in sensitivity. AUMGPC was the most representative parameter of overall isolate behavior. Although the fungicide mixture still shows good average efficacy, continuous monitoring and the adoption of integrated management strategies are recommended to preserve its effectiveness over time. Editor: Instituto Federal Goiano Tipo: Dissertação

RESISTÊNCIA MÚLTIPLA DE Amaranthus Spp. A INIBIDORES DE EPSPS E ALS EM POPULAÇÕES COLETADAS EM REGIÕES DO ESTADO DE GOIÁS

Mon, 27 Apr 2026 00:00:00 GMT

Título: RESISTÊNCIA MÚLTIPLA DE Amaranthus Spp. A INIBIDORES DE EPSPS E ALS EM POPULAÇÕES COLETADAS EM REGIÕES DO ESTADO DE GOIÁS Autor(es): Silva, Samuel Afonso Sampaio Primeiro Orientador: Cunha, Paulo César Ribeiro Abstract: The increasing occurrence of herbicide-resistant weed populations has become one of the main challenges for agricultural production. In this context, species of the genus Amaranthus stand out due to their high adaptive capacity and the occurrence of biotypes resistant to different mechanisms of action. This study aimed to evaluate the sensitivity of Amaranthus spp. populations to glyphosate (EPSPS inhibitor) and chlorimuron (ALS inhibitor) using dose–response curve methodology. The experiments were conducted under greenhouse conditions, using nine populations collected from agricultural areas in the municipalities of Cristalina and Orizona, Goiás State, Brazil. Increasing herbicide doses were applied, and visual control (%) was assessed at 28 days after application, while relative dry mass (%) was used as a complementary variable. Data were fitted to a four parameter log-logistic model (LL.4), and the doses required to achieve 50% (ED₅₀) and 80% (ED₈₀) control were estimated. For the dry mass variable, growth reduction parameters were interpreted only for populations with satisfactory model fit, while for the others, a descriptive approach based on minimum and maximum observed values was adopted. The results revealed significant differences in sensitivity among the populations. For glyphosate, most populations showed resistance, particularly POP2, POP3, POP4, and POP5, whereas POP7 and POP9 were characterized as susceptible. For chlorimuron, resistance was even more pronounced, especially in POP8, POP1, and POP5, while POP7 showed higher susceptibility. The integrated analysis of ED₅₀, ED₈₀, and resistance factors (RF) confirmed the occurrence of resistant populations. These findings indicate the presence of multiple resistance to EPSPS and ALS inhibitors in Amaranthus spp. populations in Goiás State, Brazil, highlighting the need for integrated weed management strategies to mitigate resistance evolution. Editor: Instituto Federal Goiano Tipo: Dissertação