https://tede.unioeste.br/handle/tede/576 2026-09-13T20:37:52Z 2026-09-13T20:37:52Z Schwertner, Matheus Henrique https://tede.unioeste.br/handle/tede/8636 2026-08-31T21:49:06Z 2026-05-04T00:00:00Z

Title: Interação de genes de resistência em plantas de soja visando ao controle de Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) Autor: Schwertner, Matheus Henrique Primeiro orientador: Pietrowski, Vanda Abstract: Rachiplusia nu (Guenée) (Lepidoptera: Noctuidae) caterpillars have become a key pest of soybean crops in Brazil, showing low susceptibility to some Bt technologies. The combination of native resistance genes with Bt insecticidal proteins has emerged as a promising strategy for more effective and sustainable pest management. This study aimed to evaluate the effects of combining the Bt protein (Cry1Ac + Cry1F) with native resistance genes in soybean on the biological development of R. nu. Greenhouse experiments were conducted to assess oviposition preference under both choice and no-choice conditions, and laboratory bioassays were performed to evaluate insect biology. Four soybean genotypes were used: native resistance gene + Bt (NG+Bt), Bt only (Bt), native resistance gene only (NG), and a control genotype lacking both traits. In the choice test, the NG+Bt genotype exhibited antixenosis, receiving 56% fewer eggs than the control. This effect was not observed under no-choice conditions. In the biological assays, the NG+Bt treatment showed an antibiosis effect, reducing total survival (larva-to-adult) by 51.4%, extending the developmental cycle by four days, and resulting in the lowest net reproductive rate (R₀ = 185.5). In contrast, the Btonly treatment, although reducing survival by 74.3%, prolonged the larval period and resulted in the highest cumulative foliar consumption, suggesting a compensatory feeding response. The pyramiding of native resistance genes with Bt technology (NG+Bt) proved to be the most robust strategy, combining multiple modes of action— antixenosis and antibiosis—that reduce pest establishment and foliar damage, thereby outperforming the effectiveness of individual resistance mechanisms. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação

2026-05-04T00:00:00Z Demétrio, Amanda Cristina Barilli https://tede.unioeste.br/handle/tede/8633 2026-08-28T22:37:46Z 2026-05-25T00:00:00Z

Title: Seleção de isolados de fungos entomopatogênicos e estratégia de aplicação para controle de Atta sexdens Linnaeus, 1758 (Hymenoptera: Formicidae) Autor: Demétrio, Amanda Cristina Barilli Primeiro orientador: Pietrowski, Vanda Abstract: Leaf-cutter ants cause significant damage to different agroecosystems, with conventional management based on the use of toxic baits or insecticide application in ant nests, restricting their use in agroecological areas and areas protecting native vegetation, highlighting the use of entomopathogenic fungi as a promising alternative. This work aimed to select isolates of the fungi Beauveria bassiana, Metarhizium anisopliae, and Cordyceps spp. considering pathogenicity, virulence, and productivity, changing the control of Atta sexdens via attractive baits. The bioassays were divided in two stages: (1) Pathogenicity, virulence, and productivity of the isolates; (2) use of the selected isolate to impregnate baits based on oat flakes offered to laboratory ant nests containing the queen, workers, and the cultivated fungus. (1) Twelve isolates of B. bassiana, four of M. anisopliae, two of Cordyceps fumosorosea, and one of C. javanica were tested. 1 mL of conidial suspension in distilled water + 0.01% Tween 80® (10⁹ conidia/mL) was sprayed using an airbrush coupled to an air compressor onto foraging and soldier castes collected from ant nests in the field. In the control, only distilled and sterilized water was sprayed. The insects were trapped in gerbox containers (10 insects per reproduction), containing moistened paper at the base and honey solution (10%) (22 ± 2°C, 24 hours in the dark). Isolates that caused mortality were ≥ 85% selected and compared for virulence at different concentrations (10⁶, 10⁷, and 10⁸ conidia/mL). Conidia productivity was also compared in Petri dishes with Potato-Dextrose-Agar (PDA) medium and in parboiled rice. (2) Two-year-old ant colonies maintained in a semi-climate-controlled room (22 ± 2 ºC, 24 hours of darkness) received oat-based baits with the following treatments: pure soybean oil, soybean oil + conidia (1 × 10⁹ conidia/mL), dried conidia (7 × 10¹⁰ conidia/g) and control (pure oats). The bait was offered at 4 times and the colonies were evaluated for 21 days. The parameters evaluated were ant nest weight, percentage of flake loading, attraction frequency, erratic movement, weight of the contents of the garbage chamber and dead individuals outside and inside the garbage chamber. The Unioeste 100 and 104 isolates of B. bassiana were selected, with confirmed mortality between 86 and 98%. Regarding the concentration test, there was little variation in susceptibility among the castes and concentrations evaluated. The Unioeste 100 isolate stood out for its higher productivity in PDA medium (3.24×10⁸ conidia/cm²) and in rice (3.45×10⁹ conidia/g of rice), being selected as the most suitable for the second stage. All treatments included an increase in the weight of the ant nests (from 0.6% to 10.7%) and in the percentage of infestation over time (from 10% to 49%). There was a higher occurrence of grooming, erratic movement, and dead ants outside and inside the garbage chamber in the treatments containing entomopathogenic fungus, with no difference in the weight of the garbage chamber contents. One of the ant colonies treated with oat bait and dried conidia died. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação

2026-05-25T00:00:00Z Shimada, Belmiro Saburo https://tede.unioeste.br/handle/tede/8631 2026-08-27T22:13:49Z 2022-08-31T00:00:00Z

Title: Doses de nitrogênio e potássio na cultura do milho em sistemas de cultivo orgânico e convencional Autor: Shimada, Belmiro Saburo Primeiro orientador: Duarte Júnior, José Barbosa Abstract: Corn is one of the main agricultural crops of great economic importance, being used for various purposes, requiring the adoption of methods to increase its production, such as fertilization. The objective of the work was to evaluate the agronomic characteristics of corn depending on cultivation systems and nitrogen and potassium fertilization doses in the harvest and off-season. The experiment was conducted in Palotina-PR and Assis Chateaubriand-PR, with the organic and conventional production systems, respectively, in the period from 2021 to 2022, with the second harvest (safrinha) and the normal harvest. The design used was randomized blocks in a 4 x 4 factorial scheme, with two different factors at 4 levels, with four doses of N and K2O (0, 50, 100 and 200 kg ha-1). The corn variety IPR164 was used and the variables analyzed were the agronomic characteristics (population, height, number of ears, number of rows of grains, number of grains per row, mass of one thousand grains and productivity). The agronomic characteristics did not suffer statistical differences with the treatments used in the 2nd harvest of 2021. However, in the cultivation of the normal harvest, comprising 2021/2022, the agronomic characteristics did not suffer statistical differences in the organic cultivation system, while in the conventional cultivation system presented for the number of ears and productivity. The environmental conditions present in both harvests, such as low precipitation and temperature, may have affected the plant's response to the treatments used in the present work. Nitrogen and potassium alone or together showed no statistical difference with the increase in their doses in the corn crop in both cropping systems in the off-season, while in the harvest, it only showed for the characteristics number of ears and productivity in the cropping system conventional. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação

2022-08-31T00:00:00Z Turatto, Nathalia https://tede.unioeste.br/handle/tede/8591 2026-08-05T23:46:32Z 2025-02-27T00:00:00Z

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

2025-02-27T00:00:00Z