Principais Coleções do Repositório
Submissões Recentes
Limites da educação CTSA tradicional frente à crise socioambiental
(Universidade Federal de Lavras, 2025-12-16) Souza, Vinícius Henrique; Bagdonas, Alexandre; Brido, Breno Pascal de Lacerda; Santos, Frederik Moreira dos; Lima, Guilherme da Silva; Ribeiro, Laíse Vieira Gonçalves
In this dissertation, we conduct an analysis of the field of STSE Education (Science, Technology, Society, and Environment) within the context of the contemporary socio-environmental crisis, proposing a radicalization of the field's critique based on a Marxist framework. The investigation, developed in a multi-paper structure, consists of two complementary studies – a systematic literature review that mapped and analyzed 23 works from Brazilian national production between 2014 and 2024, and a theoretical essay that addresses the identified gaps. To carry out the literature review, we used the following databases: Capes Journal Portal, SciELO, and Scopus, selecting Brazilian Portuguese articles, peer-reviewed, that explicitly align themselves with STSE Education and centrally address the environmental theme. The review results show that most of the analyzed articles (17 out of 23) present difficulties in concretely articulating the socio-environmental issue with capitalist economic, political, and social structures, with prevailing views of the Environment that approach the conservative macro-tendencies of Environmental Education. By reducing the socio-environmental crisis to administrative and individualizing issues, these views end up depoliticizing its analysis. The theoretical essay, in light of this diagnosis, advances the construction of a foundation for a Radical STSE Education, articulating categories from the Marxist framework – both from the critique of Marxist political economy and from Marxist ecology – to understand the socio-environmental crisis as an expression of the very dynamics of capitalist accumulation, with scientific and technological development being structurally conditioned by this logic.
Diversidade de Trichoderma spp. no bioma Caatinga e o potencial antagonistico no controle de Rhizoctonia solani
(Universidade Federal de Lavras, 2025-01-24) Souza , Nathalyna Lúcia Moreira; Souza, Jorge Teodoro de; Mabarch, Phellippe; Farias, Otília Ricardo de
Biological control is an important tool for managing plant diseases and has been increasingly adopted in agricultural systems. Biological control agents can occur naturally or be introduced to suppress pathogens. Among these agents, species of the genus Trichoderma have been widely used as the basis for fungicidal biological products. This study aimed to assess the diversity of Trichoderma in the Caatinga biome compared with agricultural areas, and to evaluate their effectiveness against Rhizoctonia solani. Soil samples were collected from natural Caatinga and banana (Musa spp.) plantations in Jaíba, Minas Gerais, Brazil. The mean population density of Trichoderma, estimated on semi-selective medium, was 2.5 log CFU/g of soil in the Caatinga and 1.4 log CFU/g in banana plantations, representing 8.5% and 3.4% of total fungal populations, respectively. A total of 80 isolates 54 from Caatinga and 26 from banana plantations were analyzed by BOX-PCR for genetic diversity, resulting in 67 genetic groups based on amplified band patterns. Fifteen isolates were randomly selected based on genetic grouping and identified through sequencing of the tef1 region: 4 were identified as T. longibrachiatum, 1 as T. neokoningii, 6 as T. pseudoasperelloides, and 4 as T. hunanense. In planta antagonism, assays against R. solani showed that isolate PEL39 (T. neokoningii) reduced disease incidence by 26%, and isolate RBS12 (T. pseudoasperelloides) reduced incidence by 12%, compared to the untreated control, while T. longibrachiatum and T. hunanense isolates showed no significant effect. These results highlight variability in the biocontrol activity among isolates, and future studies will focus on evaluating the antagonistic potential of untested isolates in planta.
Aplicação de matrizes biopoliméricas para revestimento de grãos de cafés especiais
(Universidade Federal de Lavras, 2025-07-25) Ribeiro, Caio Silas Ferreira; Dias, Maralí Vilela; Bufalo, Tatiana Cardoso e; Santos, Cláudia Mendes dos; Alves, Ana Paula de Carvalho
The valorization of specialty coffees has sparked the interest of producers and researchers in seeking sustainable alternatives that ensure the preservation of grain quality after harvest. Among the promising strategies, the use of edible and biodegradable coatings stands out, acting as physical and biochemical barriers, protecting the grains against adverse environmental factors. In this context, the present work aims to develop, characterize, and apply coatings based on Aloe vera, pectin, and starch, incorporating them as protective coatings for specialty coffee beans. The chosen biopolymers exhibit high availability, renewability, and excellent compatibility with food systems, while Aloe vera is known for its antioxidant and antimicrobial properties that can contribute to maintaining the quality of the grains. Formulations were prepared by varying the proportions of pectin and starch, with the addition of Aloe vera extract, aiming to optimize the physicochemical properties of the films, such as viscosity, transparency, thickness, water solubility, along with microscopic and adhesion analyses on the beans. The coffee beans were coated by immersion and stored under controlled conditions for determined periods, being monitored for water activity, coloration, volatile compound profiles, and preservation of sensory attributes. The results indicate that coatings based on starch showed superior performance in grain coating, promoting lower oxidation, and maintenance of desirable visual characteristics. The proposed approach proves promising as a clean and effective technology to increase the shelf life and quality of specialty coffees, potentially being incorporated as an innovative step in post-harvest processing. This study also reinforces the importance of applying functional biopolymers in the agroindustry, contributing to product value addition, loss reduction, and promoting sustainability in the coffee production chain.
Tanino condensado frente aos desafios inerentes da matriz suína moderna
(Universidade Federal de Lavras, 2025-10-03) Pereira, Caio Correa Janardo; Cantarelli, Vinícius de Souza; Orientador; Andretta, Ines; Freitas, Rilke Tadeu Fonseca de
Genetic improvement of hyperprolific sows has boosted swine production in recent decades. However, this advancement has been accompanied by an increase in the production of free radicals and inflammatory processes, compromising their reproduction. Condensed tannin emerges as a promising alternative to mitigate these adverse effects. Therefore, the objective of this study was to evaluate the inclusion of condensed tannin in the diet of sows and its effects on stress, productive performance, and intestinal health of the females, as well as to evaluate the impacts on the performance of their respective litters. 180 sows were used, distributed in a randomized block design, with three treatments in the gestation and lactation diets: CON – Control (without condensed tannin); TanB – 1.5 kg of condensed tannin; TanA – 2.0 kg of condensed tannin. Backfat thickness and sow weight were measured after insemination, at the exit of the gestation barn and at the exit of the farrowing barn. Feed intake was measured from the transfer of the sow to the group pen (5th-10th day of gestation) until the 19th day of lactation. Fecal microbiome analysis, colostrum bromatology, IgG concentration in colostrum, salivary cortisol and serotonin concentration, IL-10 and IL-6 concentration, and blood redox status were performed to evaluate the physiological parameters of the females. For the piglets, birth weight and weaning weight were evaluated, as well as the incidence of diarrhea, mortality, and culling. A tendency for increased feed intake (p = 0.063) was observed in the tannin treatments compared to the control. Regarding the stress response, tannin reduced cortisol concentration on the first day of lactation (p < 0.05) and showed a tendency for a higher IL-10 concentration on the 10th day of lactation for the TanA group compared to the CON group (p = 0.08). Higher catalase activity was observed in the TanA group on the 85th day of gestation (p < 0.05), higher SOD activity in the TanB group compared to the control on the first day of lactation, as well as a lower TBARS reaction in TanA on the 18th day of lactation (p < 0.05). On the 18th day of lactation, there was a trend towards a difference in beta diversity between treatments (p = 0.05), with a higher relative abundance of the Peptococcaceae family and the Lactobacillus reuteri species, in addition to a lower abundance of the Spirochaetaceae and Enterobacteriaceae families and the E. coli species (p < 0.05). The diet supplemented with condensed tannin reduces stress in sows at farrowing. Near weaning, the concentration of 2 kg/ton was able to increase intestinal health and decrease lipid oxidation.
Toxicidade de fungicidas utilizados na cultura do milho para o predador Doru luteipes (dermaptera: forficulidae)
(Universidade Federal de Lavras, 2025-09-26) Leal, Geísy Nascimento; Carvalho, Geraldo Andrade; Marucci, Rosangela Cristina; Redoan, Ana Carolina Maciel; Souza, Lívia Aparecida; Rocha, Luiz Carlos Dias
Maize crops are attacked by pests and diseases that compromise both grain quality and productivity. Among the main insect pests of this crop is Spodoptera frugiperda (Lepidoptera: Noctuidae), whose control is mainly carried out using chemical insecticides and Bt technology. However, populations of this pest can also be naturally regulated by naturally occurring natural enemies, such as the earwig Doru luteipes (Dermaptera: Forficulidae). Diseases, in turn, are mainly controlled with synthetic fungicides, which may cause biological imbalances in maize fields. Therefore, it is important that integrated pest management (IPM) programs consider the impact of pesticides on natural enemies.The aim of this study was to evaluate the toxicity of fungicides recommended for maize crops to fourth-instar nymphs (N4) and adults of D. luteipes via different exposure routes. The fungicides and their respective doses were: chlorothalonil (10.0 g/L); pyraclostrobin + epoxiconazole (5.0 mL/L); pyraclostrobin + fluxapyroxad (2.3 mL/L); mancozeb (14.0 g/L); azoxystrobin + carboxamide (1.0 g/L); azoxystrobin + difenoconazole (5.0 mL/L); and thiophanate-methyl (0.35 g/L). Negative and positive controls were distilled water and an insecticide based on Beauveria bassiana (3.25 mL/L), respectively. Fungicide applications were carried out using a Potter spray tower calibrated at 15 lb/in2 to apply 1.5 ± 0.5 μL/cm2. The exposure routes evaluated were: (i) topical application; (ii) contact with residues; (iii) ingestion of contaminated prey; and (iv) persistence on inert surfaces. The bioassays were conducted in a completely randomized design with 50 insects per treatment (10 insects per replicate). Daily mortality, egg viability, and nymph viability were assessed for all treatments. For adults, fungicides applied topically did not reduce the median lethal time (LT50). Treatments with pyraclostrobin, pyraclostrobin + epoxiconazole, and B. bassiana showed high toxicity to nymphs and adults of D. luteipes, whereas chlorothalonil and thiophanate-methyl were selective, with lower effects on survival. Toxicity varied according to the exposure route: contact with residues on inert surfaces caused greater negative effects, while ingestion of contaminated prey proved less harmful to the predator. Based on these results, it is inferred that D. luteipes exhibits natural resistance to some compounds, possibly linked to morphological characteristics and detoxification mechanisms. The fungicides evaluated showed selectivity to the predator D. luteipes, with variable toxicity depending on the exposure route. Residues of pyraclostrobin + epoxiconazole, azoxystrobin + difenoconazole, and mancozeb were lethal to nymphs and adults, whereas most products were classified as short-lived. Ingestion of contaminated prey had a lower impact on survival, and due to their high toxicity, pyraclostrobin + epoxiconazole, pyraclostrobin + carboxamide, mancozeb, and thiophanate-methyl should not be preferred for applications in maize fields when the conservation of the predator D. luteipes is intended.