https://tede.unioeste.br/handle/tede/573 Mon, 17 Aug 2026 18:29:25 GMT 2026-08-17T18:29:25Z https://tede.unioeste.br/handle/tede/8591 Title: Controle biológico de Pratylenchus brachyurus em soja via tratamento de sementes Autor: Turatto, Nathalia Primeiro orientador: Costa, Antonio Carlos Torres da Abstract: Soybean (Glycine max L.) is the most widely produced grain in Brazil under extensive cultivation. However, its productivity can be impaired when pathogens, such as the root lesion nematode Pratylenchus brachyurus, are present in its root system. Due to the difficulty in controlling this pathogen, alternative methods have been studied, such as biological control using fungi and bacteria. The objective of this study was to evaluate the effect of biological products in the control of P. brachyurus in soybean. The seeds were treated with Bacillus firmus, Bacillus amyloliquefaciens, Trichoderma harzianum, Purpureocillium lilacinum and Pochonia chlamydosporia, in addition to the untreated control. In vitro experiments were performed to evaluate the mortality of P. brachyurus and in vivo experiments to evaluate the agronomic variables (root length, root volume, fresh root mass, dry mass of the aerial part) and nematological variables (number of nematodes in the root and in the soil). The latter was performed in two different growing seasons. All experiments had five replicates and followed the manufacturer's recommendations. In the in vivo assay, inoculation was performed at the time of sowing, with the inoculum consisting of 500 specimens of P. brachyurus per pot. The biological agents acted as nematicide in the in vitro experiment. In the in vivo assays, the results indicated significance of the treatments only for dry mass of the aerial part, number of nematodes in the soil and number of nematodes in the root. In the soil, the reduction ranged from 48% to 88%, while in the root, the reduction was between 49% and 84% in the number of nematodes. Thus, the tested products have potential for controlling P. brachyurus in soybeans via seed treatment. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação Thu, 27 Feb 2025 00:00:00 GMT https://tede.unioeste.br/handle/tede/8591 2025-02-27T00:00:00Z https://tede.unioeste.br/handle/tede/8589 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 Fri, 24 Oct 2025 00:00:00 GMT https://tede.unioeste.br/handle/tede/8589 2025-10-24T00:00:00Z https://tede.unioeste.br/handle/tede/8585 Title: Manejo da ferrugem da folha (Puccinia coronata f. sp. avenae) na cultura da aveia (Avena sativa) com fungicidas microbiológicos e ácido silícico Autor: Matos, Sabrina dos Santos Primeiro orientador: Kuhn, Odair José Abstract: White oat is an important winter crop in Southern Brazil, and leaf rust, caused by Puccinia coronata f. sp. avenae, is its main disease, with the potential to cause yield losses of up to 50% in susceptible cultivars. This study aimed to evaluate the effect of microbiological fungicides and silicic acid on the management of leaf rust and on yield components of white oat. Two field experiments were conducted using the cultivar IPR Artemis. The experimental design was a randomized complete block design in a split-plot arrangement, with the presence or absence of silicic acid as the main factor and five microbiological fungicides plus a control as the secondary factor. The variables evaluated were disease severity, area under the disease progress curve, plant height, stem diameter, number of tillers, number of panicles, number of spikelets in the main panicle, thousand-grain weight, and grain yield. Silicic acid application reduced leaf rust severity by 14%. Trichodermil® and Bio-imune® reduced disease severity by 20.8% and 20.3%, respectively, compared with the control, while the association of Pardella® with silicic acid reduced the area under the disease progress curve by 17.5%. The association of Trichodermil® with silicic acid increased thousand-grain weight by 21%, although it reduced plant height and the number of spikelets in the main panicle. The use of Trichodermil® also reduced stem diameter. Grain yield was not affected by the evaluated treatments. It was concluded that silicic acid and microbiological fungicides have potential for the management of white oat leaf rust; however, they did not promote increases in grain yield under the conditions of this study. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação Fri, 28 Feb 2025 00:00:00 GMT https://tede.unioeste.br/handle/tede/8585 2025-02-28T00:00:00Z https://tede.unioeste.br/handle/tede/8507 Title: Desenvolvimento radicular e da parte aérea de estacas de goiabeira, com utilização de bioestimulantes comerciais e ácido indolbutírico Autor: Veiga, Joice Ferreira da Primeiro orientador: Villa, Fabíola Abstract: Vegetative propagation by cuttings is widely used in the production of guava seedlings (Psidium guajava L.); however, it presents physiological limitations related to rooting and the initial development of cuttings. Therefore, the objective of this study was to evaluate the root and shoot development of cuttings from four guava cultivars using commercial biostimulant products associated with indolebutyric acid (IBA). Two experiments were conducted between February and March 2025, in the seedling nursery of the State University of Western Paraná (Unioeste). Experiment I was conducted in a randomized block design, in a 4 × 4 factorial scheme (4 cultivars: Tailandesa, Paluma, Século 21 and Pedro Sato × 4 rooting treatments (IBA, IBA + ComposFix®, IBA + BioRaiz® and IBA + humic acid), with three replications and 20 cuttings per plot. For experiment II, the same design applied in the first experiment was used, in a 2 × 4 factorial scheme (2 Bacillus types × 4 product concentrations: 0, 50, 75 and 100 mL), with three replications, each replication composed of 15 cuttings, totaling 360 cuttings. The cuttings in both experiments were treated with IBA in a hydroalcoholic solution at 6,000 mg L⁻¹, by quick immersion of the base, and conducted in seedbeds containing washed sand under a protected environment. After 70 days, the percentage of rooted cuttings, number of roots, length of the longest root, number of calluses, number of shoots, shoot length, shoot diameter, and number of leaves were evaluated. The percentage of rooted cuttings did not differ statistically among treatments, although the observed values were satisfactory. It is concluded that biostimulants associated with IBA mainly influence the initial vegetative growth of cuttings, while IBA favors the development of the root system of the cultivar Paluma. The use of biological products associated with indolebutyric acid influenced the initial development of guava cuttings cv. Tailandesa, with responses dependent on the microorganism, with Bacillus subtilis standing out in the early stages of rooting. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação Fri, 20 Feb 2026 00:00:00 GMT https://tede.unioeste.br/handle/tede/8507 2026-02-20T00:00:00Z