https://tede.unioeste.br/handle/tede/577 2026-08-07T23:50:09Z 2026-08-07T23:50:09Z Mendoza Duarte, Marcos Javier https://tede.unioeste.br/handle/tede/8589 2026-08-05T21:36:46Z 2025-10-24T00:00:00Z

Title: Resistência múltipla a herbicidas, eficácia de controle de pré-emergentes e análise de crescimento em populações de Euphorbia heterophylla nas principais regiões agrícolas do Paraguai Autor: Mendoza Duarte, Marcos Javier Primeiro orientador: Costa, Neumárcio Vilanova da Abstract: A intensificação dos sistemas de produção de soja e milho no Paraguai, associada ao uso contínuo de herbicidas com mecanismos de ação semelhantes, tem favorecido a seleção de populações de E. heterophylla com diferentes padrões de resposta aos herbicidas. Até o início deste estudo, a única resistência oficialmente confirmada no país era ao imazetapir, inibidor da ALS, embora falhas frequentes de controle com glifosato fossem observadas em áreas comerciais. Além disso, no Brasil já existem registros de resistência múltipla envolvendo glifosato, fomesafen e herbicidas inibidores da ALS, evidenciando o avanço regional do problema. Diante desse cenário, formulou-se a hipótese de que populações de E. heterophylla oriundas das principais regiões agrícolas do Paraguai apresentam suscetibilidade reduzida aos herbicidas glifosato, cloransulam-metílico e fomesafen, além de alterações fisiológicas relacionadas ao crescimento vegetal. O estudo teve como objetivos identificar populações com suscetibilidade reduzida e caracterizar seus níveis de resistência, avaliar a eficácia e seletividade de herbicidas pré-emergentes no controle da espécie na soja e analisar os efeitos da resistência simples e múltipla sobre a dinâmica de crescimento vegetal. Foram coletadas sementes de 50 populações provenientes das regiões de Canindeyú, Alto Paraná, Itapúa e Caaguazú. O trabalho foi desenvolvido em três experimentos complementares envolvendo testes preliminares de suscetibilidade, ensaios de dose–resposta, avaliação da eficácia e seletividade de herbicidas pré-emergentes em campo e análise da dinâmica de crescimento de biótipos suscetível (S1), resistente à ALS (RIP4), resistente à EPSPS (RCG1) e resistente simultaneamente à ALS e à EPSPS (RCA1). Os resultados evidenciaram ampla ocorrência de populações com suscetibilidade reduzida aos herbicidas avaliados nas principais regiões agrícolas do Paraguai, especialmente nos departamentos de Alto Paraná, Canindeyú e Caaguazú. Em Alto Paraná, mais de 70% das populações apresentaram baixa suscetibilidade ao cloransulam-metílico e ao fomesafen. Os ensaios de dose–resposta confirmaram resistência em diferentes populações, com fatores de resistência de até 54,04 para glifosato, 32,23 para cloransulam-metílico e 6,31 para fomesafen. A classificação das populações quanto ao padrão de resistência indicou que 73,3% apresentaram resistência a um herbicida, 20,0% resistência simultânea a dois herbicidas e 6,7% resistência a três herbicidas, evidenciando a ocorrência de diferentes níveis de resistência simples e múltipla nas principais regiões agrícolas avaliadas. Nos ensaios de campo, sulfentrazone e S-metolachlor + fomesafen apresentaram níveis de controle superiores a 80%, constituindo os tratamentos mais eficazes para o manejo de E. heterophylla. Flumioxazin e metribuzin proporcionaram controles intermediários, entre 60 e 80%, enquanto diclosulam apresentou controle inferior a 60%. Os herbicidas avaliados apresentaram fitotoxicidade inicial transitória, com redução progressiva dos sintomas ao longo do ciclo e adequada recuperação da cultura, evidenciando seletividade agronômica para a soja nas condições experimentais. Na análise de crescimento, observaram-se diferenças na dinâmica de acúmulo de biomassa e nas taxas fisiológicas entre os biótipos avaliados. O biótipo RCA1 (ALS + EPSPS) apresentou o maior acúmulo de massa seca total, atingindo aproximadamente 1,13 g planta-1 aos 70 DAE, valor 40,5% superior ao observado no biótipo suscetível S1. O biótipo RCG1 (EPSPS) apresentou incremento de 16,9% na biomassa total em relação ao suscetível, enquanto RIP4 (ALS) apresentou redução de aproximadamente 18,0%. Os maiores picos de taxa de crescimento absoluto (TCA) foram observados em RCA1 e RCG1, com valores de aproximadamente 0,039 e 0,037 g dia-1, respectivamente, correspondendo a incrementos de 49,3% e 42,9% em relação ao S1. O biótipo RIP4 apresentou o maior pico de taxa assimilatória líquida (TAL), atingindo aproximadamente 0,0017 g cm-2 dia-1 aos 48–50 DAE, valor 96,9% superior ao suscetível. Por outro lado, S1 apresentou a maior taxa de crescimento relativo (TCR), com pico de aproximadamente 0,150 g g-1 dia-1 aos 40 DAE, enquanto os biótipos RCG1, RCA1 e RIP4 apresentaram reduções de 22,0%, 45,0% e 49,2%, respectivamente. Concluem-se que existe uma ampla disseminação de populações de E. heterophylla com suscetibilidade reduzida a diferentes mecanismos de ação herbicida nas principais regiões produtoras de soja do Paraguai. Sulfentrazone e S-metolachlor + fomesafen constituem alternativas eficientes para o manejo da espécie em pré-emergência. Adicionalmente, a resistência promoveu alterações na dinâmica de crescimento e na partição de biomassa, indicando que os efeitos fisiológicos associados à resistência dependem do mecanismo envolvido.; The intensification of soybean and corn production systems in Paraguay, combined with the continuous use of herbicides with similar mechanisms of action, has favored the selection of E. heterophylla populations with different response patterns to herbicides. At the beginning of this study, the only officially confirmed case of herbicide resistance in the country was resistance to imazethapyr, an ALS inhibitor, although frequent glyphosate control failures had been reported in commercial fields. Furthermore, cases of multiple resistance involving glyphosate, fomesafen, and ALS-inhibiting herbicides have already been reported in Brazil, highlighting the regional expansion of this issue. Based on this scenario, the hypothesis was established that E. heterophylla populations from the main agricultural regions of Paraguay exhibit reduced susceptibility to glyphosate, chloransulam-methyl, and fomesafen, as well as physiological alterations associated with plant growth. The objectives of this study were to identify populations with reduced susceptibility and characterize their resistance levels, evaluate the efficacy and selectivity of pre-emergence herbicides for E. heterophylla control in soybean, and assess the effects of single and multiple resistance on plant growth dynamics. Seeds were collected from 50 populations originating from the regions of Canindeyú, Alto Paraná, Itapúa, and Caaguazú. The study was conducted through three complementary experiments involving preliminary susceptibility screening, dose-response assays, field evaluation of the efficacy and selectivity of pre-emergence herbicides, and growth analysis of susceptible (S1), ALS-resistant (RIP4), EPSPS-resistant (RCG1), and ALS + EPSPS-resistant (RCA1) biotypes. The results revealed a widespread occurrence of populations with reduced susceptibility to the evaluated herbicides across the main agricultural regions of Paraguay, particularly in Alto Paraná, Canindeyú, and Caaguazú. In Alto Paraná, more than 70% of the populations exhibited reduced susceptibility to chloransulam-methyl and fomesafen. Dose-response assays confirmed resistance in different populations, with resistance factors reaching 54.04 for glyphosate, 32.23 for chloransulam-methyl, and 6.31 for fomesafen. Classification of populations according to resistance pattern indicated that 73.3% exhibited resistance to a single herbicide, 20.0% exhibited simultaneous resistance to two herbicides, and 6.7% exhibited resistance to three herbicides, demonstrating the occurrence of different levels of single and multiple resistance across the evaluated agricultural regions. In field trials, sulfentrazone and S-metolachlor + fomesafen provided control levels above 80%, constituting the most effective treatments for E. heterophylla management. Flumioxazin and metribuzin provided intermediate control levels, ranging from 60 to 80%, whereas diclosulam resulted in control levels below 60%. All evaluated herbicides caused only transient initial phytotoxicity, with progressive symptom reduction throughout the crop cycle and adequate crop recovery, demonstrating satisfactory agronomic selectivity for soybean under the experimental conditions. Growth analysis revealed differences in biomass accumulation dynamics and physiological growth parameters among the evaluated biotypes. The RCA1 biotype (ALS + EPSPS) exhibited the highest total dry matter accumulation, reaching approximately 1.13 g plant⁻¹ at 70 days after emergence (DAE), representing a 40.5% increase compared with the susceptible biotype S1. The RCG1 biotype (EPSPS) exhibited a 16.9% increase in total biomass relative to S1, whereas RIP4 (ALS) showed an approximately 18.0% reduction. The highest absolute growth rate (AGR) peaks were observed in RCA1 and RCG1, reaching approximately 0.039 and 0.037 g day-1, respectively, corresponding to increases of 49.3% and 42.9% compared with S1. The RIP4 biotype exhibited the highest net assimilation rate (NAR), reaching approximately 0.0017 g cm-2 day-1 at 48–50 DAE, representing a 96.9% increase compared with the susceptible biotype. In contrast, S1 exhibited the highest relative growth rate (RGR), reaching approximately 0.150 g g-1 day1 at 40 DAE, whereas RCG1, RCA1, and RIP4 showed reductions of 22.0%, 45.0%, and 49.2%, respectively. The results demonstrate the widespread distribution of E. heterophylla populations with reduced susceptibility to different herbicide mechanisms of action across the major soybean-producing regions of Paraguay. Sulfentrazone and Smetolachlor + fomesafen represent effective alternatives for pre-emergence management of this species. Furthermore, herbicide resistance altered growth dynamics and biomass partitioning, indicating that the physiological effects associated with resistance depend on the underlying resistance mechanism. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Tese

2025-10-24T00:00:00Z Kohler, Taís Regina https://tede.unioeste.br/handle/tede/8506 2026-07-14T12:19:36Z 2026-03-30T00:00:00Z

Title: Leveduras e seus efeitos no manejo biológico de antracnose em soja e na promoção de crescimento vegetal Autor: Kohler, Taís Regina Primeiro orientador: Kuhn , Odair José Abstract: Yeasts have proven to be a promising and sustainable strategy for disease management and plant growth promotion in agricultural systems. Therefore, the objective was to evaluate the potential of yeasts in the biological control of anthracnose and the effect of these yeasts on growth promotion in soybean plants. To this end, in vitro assays were performed to evaluate the effects of eight yeast species on mycelial growth and spore germination of Colletotrichum truncatum. In a greenhouse, assays were conducted to verify the effect of these yeasts on reducing the severity of anthracnose in soybeans, as well as the possible mechanisms related to plant defense involved. Finally, an assay was performed to analyze the growth promotion of soybean plants when treated with the yeasts. It was found that none of the eight yeasts interfered with the mycelial growth of C. truncatum. Candida albicans showed an average of 42.5% inhibition of conidia germination. The other yeasts did not inhibit the germination of C. truncatum conidia. Yeasts also did not reduce the severity of anthracnose in soybean plants under the assay conditions. However, Rhodotorula glutinis and Pichia pini were able to induce defensive metabolism in soybean plants, acting through different mechanisms of action, but not against C. truncatum under the assay conditions. R. glutinis increased polyphenol oxidase enzyme activity by 200%. P. pini induced β-1,3-glucanase enzyme activity by 98% after the presence of the pathogen. However, Sporidiobolus johnsonii, Zygoascus hellenicus, R. glutinis, and Rhodotorula aurantiaca induced promising increases in different agronomic variables related to plant growth. S. johnsonii increased the total number of trifoliate leaves by 31%, the number of flowers by 164%, the number of vegetative/reproductive branches by 45%, the shoot dry mass by 45%, the root volume by 114%, and the root fresh mass by 121%. Meanwhile, Z. hellenicus increased the number of vegetative/reproductive branches by 42%, the root volume by 90%, and the root fresh mass by 80%. R. glutinis showed a 31% increase in the number of vegetative/reproductive branches and a 37% increase in shoot dry mass, and R. aurantiaca also showed a 28% increase in the number of vegetative/reproductive branches. It is concluded that the yeasts in the assay were not efficient in controlling C. truncatum under the tested conditions; however, they were able to promote resistance mechanisms and contribute to plant growth in soybean plants. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Tese

2026-03-30T00:00:00Z Vargas, Rodrigo José de https://tede.unioeste.br/handle/tede/8462 2026-06-12T21:51:10Z 2026-03-26T00:00:00Z

Title: Bioinsumos na produção de mudas de oliveira: efeitos no enraizamento de estacas e no desenvolvimento em viveiro Autor: Vargas, Rodrigo José de Primeiro orientador: Villa, Fabíola Abstract: The olive tree (Olea europaea L.) is predominantly propagated by cuttings, conventionally using indole-3-butyric acid (IBA) to induce rooting and sand as a substrate. The application of bioinputs based on plant growth-promoting microorganisms represents a potential alternative for improving rooting efficiency. This study was conducted to evaluate, in two experiments, the rooting capacity of olive cultivars using microbial biostimulants and the effect of different biostimulants on seedling development during the nursery phase. The first experiment, focused on cutting rooting, was carried out in October using four olive cultivars: Arbequina, Maria da Fé, Ascolano 315, and Koroneiki. Cuttings were prepared and placed in masonry beds containing sand as substrate under controlled humidity and temperature conditions. The experimental design was completely randomized in a 6 × 4 factorial scheme (six biostimulants × four cultivars), with four replications and 25 cuttings per replication, totaling 100 cuttings per treatment. In addition to the control treatment (T1, IBA only), treatments consisted of biostimulants associated with IBA, including three Bacillus species: Bacillus amyloliquefaciens (T2), Bacillus licheniformis (T3), Bacillus subtilis (T4), Trichoderma harzianum (T5), and the commercial rooting product Bioraiz® (T6), all applied in liquid form to the substrate. Solutions were prepared according to the manufacturers’ recommendations, with a final volume of 3000 mL per treatment. Evaluations included rooting percentage, callus formation, and root system characteristics. The results indicated that the application of biostimulants enhanced rooting, with responses varying among cultivars. Increased rooting percentages were observed in the cultivars Maria da Fé, Ascolano 315, and Arbequina when treated with Trichoderma harzianum and Bacillus spp. Callus formation, particularly in Arbequina, was greater in the presence of Trichoderma harzianum, suggesting that this microorganism induces physiological processes related to rhizogenesis and improves root emission. The second experiment was conducted using olive seedlings approximately one year old, derived from the rooting phase and maintained under 70% shading. The experimental design was completely randomized in a 4 × 4 factorial scheme (cultivars × biostimulants), with three replications per treatment and two plants per replication. Plant height, stem diameter, and SPAD index were measured monthly over four months. Destructive analyses were performed to determine fresh and dry biomass of shoots and roots. The results demonstrated that seedling responses to biostimulants depended on genotype and the type of product applied, indicating interaction between cultivar and treatment. The use of seaweed extract proved promising for cultivars such as Ascolano 315, promoting greater initial growth and root system expansion. The use of microbial bioinputs can contribute to improved rooting of cuttings and enhanced growth of olive seedlings under nursery conditions. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Tese

2026-03-26T00:00:00Z Reis, Willian dos https://tede.unioeste.br/handle/tede/8010 2025-08-12T19:58:32Z 2025-05-23T00:00:00Z

Title: Qualidade física, carbono orgânico do solo e produtividade de milho e soja após aplicação de remineralizador basáltico associado a cama de frango e consórcios de plantas de cobertura Autor: Reis, Willian dos Primeiro orientador: Seidel, Edleusa Pereira Abstract: The objective of this study was to evaluate the effect of basalt rock powder associated with cover crops and chicken litter on soil physical properties, total soil organic carbon (TOC), cover crop dry matter yield, and corn and soybean yield. The experimental design was randomized block in a splitstrip scheme with two additional treatments and four replicates. The primary strips consisted of three cover crop consortia: black oat + forage turnip (mix 1); white lupin + forage pea (mix 2); and oat + turnip + lupin + pea (mix 3). The secondary strips were: presence or absence of chicken litter (6 Mg ha-1). The sub-stripes were: presence or absence of rock powder (8 Mg ha-1). The additional treatments were: absolute control and control with chemical fertilizer. Penetration resistance (PR) down to 0.40 m, bulk density, porosity, and total soil carbon were evaluated in four layers (0.00.05; 0.05-0.10; 0.10-0.15, and 0.15-0.20 m) before and after harvesting summer crops (12 and 24 months after the start of the experiment). The dry mass productivity of cover crops was determined during the flowering period. Summer crops were manually harvested in the useful area of the plots, threshed, and weighed to assess productivity. The dry mass productivity of consortia was higher in the presence of rock powder and chicken litter; the use of rock powder, chicken litter, and cover crops in consortia provided higher soil TOC content; the use of chicken litter, as well as the association of cover crops in the presence of rock powder, promoted a reduction in PR; the consortia and the use of chicken litter and rock powder did not reduce soil density, but did not negatively interfere with macroporosity, microporosity and soil PT; the use of rock powder and chicken litter provided greater corn and soybean productivity. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Tese

2025-05-23T00:00:00Z