https://repositorio.ufu.br/handle/123456789/5161 2026-08-29T03:33:50Z 2026-08-29T03:33:50Z https://repositorio.ufu.br/handle/123456789/49969 2026-08-28T17:46:54Z 2026-04-24T00:00:00Z

Title: Alterações dos atributos físicos e estoque de carbono do solo em diferentes sistemas de manejo no Cerrado Abstract: The conversion of native Cerrado areas into agricultural systems has promoted changes in soil physical attributes and organic carbon dynamics, potentially affecting soil structure maintenance, water availability, and carbon storage capacity in cultivated environments. This study evaluated the effects of different sugarcane management systems on soil physical attributes and organic carbon stocks in Red Latosols in the Triângulo Mineiro region, Minas Gerais, Brazil. Six soil use and management systems were evaluated: Conv. 2 (conventional cultivation with two years of implementation), Conv. 3 (conventional cultivation with three years of implementation), Min. Till. 2 (minimum tillage with two years of implementation), Min. Till. 3 (minimum tillage with three years of implementation), Pasture, and Native Forest as an environmental reference. Soil samples were collected at depths of 0–10, 10–20, and 20 40 cm and analyzed for soil bulk density, macroporosity, microporosity, total porosity, mean weight diameter, geometric mean diameter, aggregate stability index, total organic carbon, and carbon stocks. The experiment was conducted in a completely randomized design in a factorial arrangement, considering six management systems, three soil depths, and five replications. Data were subjected to analysis of variance, and means were compared using Tukey’s test at a 5% significance level. The results demonstrated that management was the main factor responsible for changes in the evaluated attributes, whereas soil depth and the interaction between management and depth had a lower influence on most variables. The Min. Till. 3 system showed more favorable soil physical conditions, characterized by lower soil bulk density, higher macroporosity (24.17%), and higher total porosity (47.93%), presenting a similar behavior to Native Forest. The attributes related to aggregate stability showed greater structural preservation in Pasture and Native Forest systems, which presented higher values of geometric mean diameter, mean weight diameter, and aggregate stability index, highlighting the importance of permanent soil cover and continuous organic residue input. Management systems also influenced total organic carbon contents, with higher values observed in Min. Till. 2, Conv. 2, and Min. Till. 3 systems. Carbon stocks were affected by the evaluated management systems, with Min. Till. 3 presenting the highest carbon stock (43.40 Mg ha⁻¹), followed by Pasture and Native Forest. It is concluded that conservation management systems, especially minimum tillage after three years of implementation, have the potential to improve soil physical quality and increase carbon stocks in sugarcane cultivated areas in the Cerrado, contributing to agricultural sustainability strategies and natural resource conservation.

2026-04-24T00:00:00Z https://repositorio.ufu.br/handle/123456789/49904 2026-08-28T06:19:40Z 2026-07-31T00:00:00Z

Title: Controle de plantas daninhas com Cletodim e 2,4–D aplicados por um sistema de tanques e barras simples e duplas em diferentes taxas de aplicação Abstract: Chemical weed management is essential for agricultural productivity and is widely based on the use of herbicides, particularly tank mixtures of herbicides and other products applied simultaneously. However, tank mixing may result in herbicide antagonism, reducing weed control efficacy. In addition, factors such as application rate and application technology directly influence herbicide performance, highlighting the importance of strategies that minimize incompatibilities. Therefore, this study aimed to evaluate the efficacy of the herbicides clethodim and 2,4-D applied during desiccation using a simple and dual tank and boom spraying system at different application rates. The experiment was conducted at the Araras Campus of the Federal University of Uberlândia, located in Monte Carmelo, Minas Gerais, Brazil, using a completely randomized design with seven treatments and four replications. Seven application systems were evaluated: tank-mixed herbicides applied with a single boom at application rates of 60 and 120 L ha⁻¹; two tanks with herbicides mixed directly at the boom at application rates of 60 and 120 L ha⁻¹; and two tanks with two independent booms (without herbicide mixing at any point in the spraying circuit) at three application rate combinations (60 L ha⁻¹ total, with 30 L ha⁻¹ applied per boom; 120 L ha⁻¹ total, with 60 L ha⁻¹ per boom; and 240 L ha⁻¹ total, with 120 L ha⁻¹ per boom). Spray solutions consisted of water, 2,4-D (Aminol®; 670 g a.e. ha⁻¹), clethodim (Poquer®; 108 g a.i. ha⁻¹), and mineral oil (Iharol Gold®; 0.5% v/v). Weed control was visually evaluated according to the Brazilian Weed Science Society (SBCPD, 1995) rating scale at 7, 14, and 21 days after application (DAA) for four representative weed species in the experimental area: two monocotyledonous species (Brachiaria decumbens and Digitaria horizontalis) and two dicotyledonous species (Alternanthera tenella and Richardia brasiliensis). Data were subjected to analysis of variance (ANOVA), and means were compared using Tukey’s test at the 5% significance level with R software®. The application system directly influenced weed control efficacy. Treatments that reduced (two tanks with boom mixing) or eliminated (two tanks with two independent booms) prior contact between clethodim and 2,4-D generally provided superior performance, particularly for the evaluated monocotyledonous species (Brachiaria decumbens and Digitaria horizontalis) and for the overall weed control at 14 and 21 DAA. The adoption of spraying technologies capable of preventing or minimizing prior mixing between ACCase-inhibiting and auxin-mimicking herbicides at application rates of 60 or 120 L ha⁻¹ represents a promising strategy to improve burndown application efficiency, contributing to more efficient, rational, and operationally feasible chemical weed management.

2026-07-31T00:00:00Z https://repositorio.ufu.br/handle/123456789/49879 2026-08-28T06:19:44Z 2026-02-10T00:00:00Z

Title: Patogenicidade de agroathelia coffeicola em tecidos foliares de samambaia e cafeeiro Abstract: This study aimed to evaluate the pathogenicity of the fungus Agroathelia coffeicola isolated from bracken fern (Pteridium sp.) in leaf tissues of bracken fern (Pteridium sp.) and coffee plants (Coffea arabica) using different inoculation methods; to compare the severity between A. coffeicola isolates; to compare the severity in bracken fern and coffee plants; and to compare inoculation methods with and without wounding. The isolates were cultivated in potato-dextrose-agar medium and prepared for inoculation by two methods: without injury, using mycelial plugs of 3 mm in diameter; with injury using a wooden stick colonized by mycelium; and as controls, water-agar plugs and sterilized sticks were used, respectively. The inoculated leaf tissues were placed in acrylic boxes to create humid chambers, which were maintained using filter paper and distilled water, both sterilized. Ten days after inoculation (DAI), photographic documentation was performed to assess severity using ImageJ software. The tested isolates caused light brown necrotic spots on the leaf tissues of ferns and coffee plants and produced white aerial mycelium and light brown sclerotia. The two isolates evaluated did not show a difference in aggressiveness. The toothpick wounding method caused greater severity compared to the mycelial plug contact method. The A. coffeicola isolates used, originating from bracken fern, caused greater severity in bracken fern compared to coffee plants.

2026-02-10T00:00:00Z https://repositorio.ufu.br/handle/123456789/49863 2026-08-27T06:21:32Z 2026-07-03T00:00:00Z

Title: Uso de isolados de alternaria spp. para o controle biológico do caruru amaranthus hybridus e A. retroflexus Abstract: Weeds are among the primary factors limiting agricultural productivity, as they compete with crops for water, light, nutrients, and space. Among the most significant species are Amaranthus hybridus and Amaranthus retroflexus, which are widely distributed in agricultural areas and are recognized for their high infestation potential and competitiveness. Management of these species relies primarily on the application of chemical herbicides. However, the continuous use of these products has led to the selection of herbicide-resistant weed populations and raised concerns regarding environmental impacts, highlighting the need for more sustainable alternatives. In this context, this study aimed to evaluate the potential of different Alternaria spp. isolates for the biological control of A. hybridus and A. retroflexus. The experiment was conducted at the Microbiology and Phytopathology Laboratory of the Federal University of Uberlândia, Monte Carmelo Campus. Four Alternaria spp. isolates (BANI001, BA031, BANI032, and BANI045) were individually applied to post-emergence plants of the target species. Evaluations were conducted seven days after inoculation by observing symptoms of chlorosis, necrosis, and plant mortality, as well as by quantifying the plant population before and after treatment. The percentage of weed control was estimated using the rating scale established by the Brazilian Society of Weed Science, accounting for both symptom severity and population reduction. Results indicated differences in the aggressiveness of the isolates toward the target species. Isolate BANI001 achieved the highest level of control (52%) and was classified as providing moderate control. Isolate BANI045 provided 43% control of A. hybridus, also categorized as moderate. In contrast, isolate BANI032 achieved 15% control of A. retroflexus, while BA031 reached 25%; both were classified as providing low or ineffective control. It is concluded that Alternaria spp. isolates show potential for the biological control of A. hybridus and A. retroflexus, with BANI001 and BANI045 standing out for providing moderate control under the evaluated conditions. These findings underscore the potential for further studies aimed at developing sustainable weed management strategies. Notes: 46

2026-07-03T00:00:00Z