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Eficácia do florpirauxifeno-benzílico em associação com herbicidas na dessecação pré-colheita da soja e efeito de horários de aplicação na ação do diquate

2026-10-01T05:07:12Z

Título: Eficácia do florpirauxifeno-benzílico em associação com herbicidas na dessecação pré-colheita da soja e efeito de horários de aplicação na ação do diquate Autor(es): Oliveira, Estefani Kariane Primeiro Orientador: Mauad, Munir Abstract: Pre-harvest desiccation of soybean is a management practice used to standardize maturation, anticipate harvest, and reduce the risk of losses and deterioration, highlighting the need to evaluate herbicides as alternatives to paraquat and to understand how interactions with the environment affect their effectiveness. Thus, the objective of this study was to evaluate the efficiency of florpyruxifen-benzyl applied alone and in association with the herbicides diquat, tiafenacil, flumioxazin, ammonium glufosinate, amicarbazone, and carfentrazone-ethyl in soybean pre-harvest desiccation, as well as to assess the effect of different application times on the performance of diquat. The study was conducted in two distinct experiments. Experiment 1 was carried out during the 2023/24 growing season, in a randomized complete block design (RCBD), with seven treatments and four replications, and experiment 2 was conducted during the 2024/25 growing season, also in RCBD, with eight treatments and four replications. In experiment 1, agronomic performance and the dynamics of light action after pre-harvest application of diquat were evaluated. Light dynamics were assessed by applying diquat at different times of the day in order to provide distinct periods of light exposure following application. Thus, treatments with 12, 8, and 4 hours of light or darkness immediately after application were established, as follows: T1 – 12 hours of light (06:20); T2 – 8 hours of light (10:20); T3 – 4 hours of light (14:20); T4 – 12 hours of darkness (18:20); T5 – 8 hours of darkness (22:20); T6 – 4 hours of darkness (02:20); and T7 – untreated control, allowing the evaluation of the effect of light exposure duration on the speed of herbicide action. In experiment 2, defoliation and desiccation (visual assessment and ImageJ analysis), moisture reduction over days after application (DAA), electrical conductivity (EC), thousand-grain weight (TGW), and yield were evaluated. The applied treatments were as follows: T1 – diquat (0.5 L ha⁻¹) + florpyruxifen-benzyl (0.1 L ha⁻¹); T2 – tiafenacil (0.3 L ha⁻¹) + florpyruxifen-benzyl (0.1 L ha⁻¹); T3 – flumioxazin (0.05 L ha⁻¹) + florpyruxifen-benzyl (0.1 L ha⁻¹); T4 – ammonium glufosinate (0.26 L ha⁻¹) + florpyruxifen-benzyl (0.1 L ha⁻¹); T5 – amicarbazone (0.13 L ha⁻¹) + florpyruxifen-benzyl (0.1 L ha⁻¹); T6 – florpyruxifen-benzyl applied alone (0.1 L ha⁻¹); T7 – carfentrazone ethyl (0.6 L ha⁻¹) + florpyruxifen-benzyl (0.1 L ha⁻¹); and T8 – untreated control. For the different diquat application times, no statistical difference was observed between treatments and the control when defoliation was evaluated. All treatments promoted greater desiccation than the control, reaching 100% desiccation at the end of the evaluation period, whereas the control reached a maximum of 93.25%. Regarding grain moisture, all treatments were superior to the control, with diquat applications at different times resulting in moisture contents between 13% and 16%, while the control remained above 19%. Treatments with 12, 8, and 4 hours of light exposure immediately after application resulted in the lowest moisture contents (below 14%) at the end of the evaluation period. Different application times did not influence final crop yield, with no statistical differences observed between treatments and the control. The use of florpyruxifen-benzyl, both alone and in association with other herbicides, showed superior performance compared to the control in terms of defoliation and desiccation, with no significant differences among treatments at the end of the evaluation period. However, treatment T1 (diquat + florpyruxifen-benzyl) achieved 100% desiccation and defoliation in a shorter time compared to the other treatments and the control. Regarding grain moisture, all herbicide treatments showed superior performance, and significant differences among treatments were observed at the end of the evaluation period. Treatments T1 (diquat + florpyruxifen-benzyl), T2 (tiafenacil + florpyruxifenbenzyl), and T6 (carfentrazone-ethyl + florpyruxifen-benzyl), in addition to achieving the lowest moisture contents (below 14%), also showed potential to anticipate harvest by up to seven days compared to the control and by two days compared to the other treatments. For TGW and yield, all treatments were superior to the control. It is concluded that diquat application times that allow greater exposure to sunlight immediately after application promote greater moisture reduction without affecting final yield. The use of florpyruxifen-benzyl associated with diquat (T1) promotes faster desiccation, defoliation, and moisture reduction, and together with treatments T2 (tiafenacil + florpyruxifenbenzyl) and T6 (carfentrazone-ethyl + florpyruxifen-benzyl), shows potential to anticipate soybean harvest by up to seven days compared to the control, while the other treatments anticipate harvest by up to five days compared to the control. Editor: Universidade Federal da Grande Dourados Tipo: Dissertação

Aplicação foliar de zinco como estratégia para mitigar estresses abióticos na cultura do trigo, sob condições do ecótono Cerrado-Mata Atlântica

2026-10-01T05:07:10Z

Título: Aplicação foliar de zinco como estratégia para mitigar estresses abióticos na cultura do trigo, sob condições do ecótono Cerrado-Mata Atlântica Autor(es): Castel, Dijovano Dal Primeiro Orientador: Mauad, Munir Abstract: The Brazilian Cerrado, particularly in the state of Mato Grosso do Sul (MS), offers a promising landscape for the expansion of wheat cultivation; however, it poses significant challenges due to water instability and high temperatures during the growing cycle—factors that induce abiotic and oxidative stress in the crop. Foliar fertilization emerges as a promising strategy for mitigating the effects of oxidative stress. In this context, zinc (Zn) stands out as an essential micronutrient for plants, playing a multifaceted role in metabolism (photosynthesis, carbohydrate metabolism, protein synthesis, growth regulation, and reproductive development) and antioxidant defense. This study aimed to evaluate the effect of foliar zinc (Zn) application at different phenological stages as a strategy to mitigate abiotic stresses in wheat under the conditions of the Cerrado-Atlantic Forest ecotone. The experiment was conducted in Dourados, MS, over two growing seasons (2024 and 2025), using a randomized complete block design with four replications. Seven foliar Zn application treatments (100 g ha⁻¹) were evaluated, including a control (no application), single applications (at stages GS2, GS10, and GS10.5.1), and split applications (GS2+GS10, GS2+GS10.5.1, and GS10+GS10.5.1), utilizing the cultivars TBIO Calibre (2024) and TBIO Titan (2025). The variables analyzed included plant height, spike length, number of grains per spike, number of grains per spikelet, number of spikelets per spike, thousand-grain weight, grain yield, test weight, protein content, peroxidase, and superoxide dismutase. Data were subjected to analysis of variance and Tukey’s test (p<0.05). Results from the 2024 season demonstrated that split Zn applications—particularly GS2+GS10 and GS10+GS10.5.1—promoted increases in yield components, such as plant height, spike length, number of grains per spike, and number of grains per spikelet. No significant effects were observed in the 2025 season. Although grain yield did not show significant differences between treatments in either season, yield increments of 20.38% (2024) and 8.68% (2025) were observed relative to the control. In both seasons, split management resulted in higher activity of the antioxidant enzymes Peroxidase and Superoxide Dismutase, with increases of 250% (2024) and 33.33% (2025) for the former, and 10.47% (2024) and 9.73% (2025) for the latter, demonstrating improved physiological stability. It was concluded that split foliar zinc application, especially at stages GS2+GS10 and GS10+GS10.5.1, constitutes an effective strategy to strengthen the wheat antioxidant system and optimize agronomic performance, providing greater resilience to the abiotic stresses typical of the Cerrado. Editor: Universidade Federal da Grande Dourados Tipo: Dissertação

Épocas de semeadura de trigo para expressão do maior potencial agronômico

2026-10-01T05:07:06Z

Título: Épocas de semeadura de trigo para expressão do maior potencial agronômico Autor(es): Tosetti, Gabriel Menta Primeiro Orientador: Mauad , Munir Abstract: The state of Mato Grosso do Sul has potential for expanding triticulture. Understanding the phytotechnical behavior of agricultural crops for the region is necessary for better positioning of cultivars. The aim of this study was to present a phytotechnical analysis of wheat cultivars at sowing times in the south of Mato Grosso do Sul, establishing the factors that have the greatest impact on crop development, in order to identify the period that offers the best environmental conditions for expressing production potential. The experiment was carried out over two agricultural years (2022 and 2023), with 4 sowing seasons (1st and 2nd half of April, 1st and 2nd half of May) and 2 wheat cultivars (TBIO Ponteiro and IPR Catuara), totaling 32 experimental plots. The following were evaluated: date of emergence, beginning of tillering, flowering, maturity and phytotechnical variables: plant height, number of ears per meter, number of spikelets per ear, number of grains per spikelet, number of grains per ear, mass of grains per ear and yield. The data was subjected to analysis of variance and the Tukey test for comparing means (p>0.05). The results showed an interaction between cultivar and sowing time in 2022 for all the variables studied. In 2023, there was no interaction in the following variables: plant height and spikelets per plant. It was concluded that the first sowing season (1st half of April) was more favorable for sowing wheat in the south of Mato Grosso do Sul. Editor: Universidade Federal da Grande Dourados Tipo: Dissertação

Atributos químicos e microbiológicos do solo e produtividade da soja em função de manejos de solo e de culturas

2026-09-26T05:07:05Z

Título: Atributos químicos e microbiológicos do solo e produtividade da soja em função de manejos de solo e de culturas Autor(es): Meurer, Hercules Lazari Primeiro Orientador: Ceccon, Gessí Abstract: No-tillage is widely adopted in Brazil; however, studies evaluating how different soil management methods used during system establishment influence the long-term dynamics of soil chemical and microbiological attributes are still limited. Therefore, this study aimed to evaluate the residual effect of different soil management systems used during the establishment of no-tillage, associated with autumn–winter crops, on soil chemical and microbiological attributes, as well as soybean yield. The experiment was carried out at Embrapa Agropecuária Oeste, in Dourados, MS, Brazil, on a very clayey dystroferric Red Latosol. The experiment followed a 4 × 4 factorial arrangement in a randomized block design and three replications. The first factor consisted of soil management practices: disc plow, moldboard plow, chisel plow, and no-tillage. The second factor comprised autumn–winter crops: maize, maize + Brachiaria ruziziensis, B. ruziziensis + Crotalaria ochroleuca, and a crop mixture (maize + B. ruziziensis + C. ochroleuca + C. spectabilis + Vigna radiata L.). Prior to soybean sowing, soil samples were collected to evaluate chemical attributes, and at the R1 stage to assess microbiological attributes. Soybean yield components were evaluated at the R6 stage, and grain yield was determined at harvest. Data were subjected to analysis of variance and Pearson correlation analysis, and means were compared using the Tukey test (P < 0.05). Soil management systems used during the establishment of no-tillage mainly affected soil chemical attributes, promoting nutrient redistribution within the soil profile, with phosphorus levels in the 10–20 cm layer ranging from 15.29 mg dm⁻³ under no-tillage to 24.96 mg dm⁻³ under disk plowing. Autumn-winter crops had a localized effect on surface phosphorus, with the highest value observed in the B. ruziziensis + C. ochroleuca intercrop (46.54 mg dm⁻³). Soil management systems resulted in residual effects on soybean yield components, such as 100-grain weight, but did not lead to significant differences in grain yield. It is concluded that soil disturbance associated with lime incorporation during the establishment of no-tillage promotes nutrient redistribution without negative residual effects on soil microbiota and soybean yield after four years. Editor: Universidade Federal da Grande Dourados Tipo: Dissertação