Principais Coleções do Repositório
Submissões Recentes
dissertação
Liofilização, uma alternativa promissora para a conservação de sementes de Coffea Arabica L.
(Universidade Federal de Lavras, 2025-08-28) Mizael, Rafaela Rezende; Rosa, Sttela Dellyzete Veiga Franco da; Ferreira, Ana Maria Oliveira; Fávaris, Nathália Aparecida Bragança; Pires, Raquel Maria de Oliveira; Pereira, Cristiane Carvalho
The preservation of coffee seeds still represents a major challenge for coffee farming due to the loss of their physiological quality after six to eight months of storage. This characteristic is related to the sensitivity of the seeds to desiccation. Coffea arabica L. seeds are classified as intermediate because they do not tolerate low water content. In this context, freeze-drying emerges as an alternative by promoting water removal through sublimation at low temperatures and under vacuum, preserving cellular structures and metabolic functions for prolonged periods. The objective of this study was to evaluate the survival of Arabica coffee seeds after freeze-drying and storage at room temperature. In a first experiment, seeds of the cultivar MGS Paraíso 2 were dried on silica gel or suspended sieves to water contents of 35, 30, 25, 20, 15, and 12% (wet basis) and subsequently freeze-dried to approximately 5% moisture (wt). Physiological quality was evaluated by germination, tetrazolium, and electrical conductivity tests. In a second experiment, the performance of freeze-dried seeds was evaluated using the same tests during nine months of storage after drying on silica gel or suspended sieves to the moisture levels mentioned above. Freeze-drying compromised the formation of normal seedlings in freeze-dried and pre-dried seeds between 35% and 12% moisture, while viability was not affected at moisture levels of 15% and 20%. After nine months of storage without temperature control, more than 80% of the freeze-dried seeds with 12% moisture remained viable and with a high percentage of root protrusion.
Artigo
Diálogos entre a estratégia como prática e a teoria institucional: uma revisão integrativa
(2022-09) Morais, Raphael de; Brito, Mozar José de; Brito, Valéria da Glória Pereira; Pinheiro, Daniel Calbino; Prado, Agda da Silva
The theoretical-methodological dialogue between the approach of strategy as practice and other approaches formulated by social theorists has produced significant contributions to the advancement of knowledge about “making strategy.” The link between the new institutionalism and the approach to strategy as a practice has been stimulated and articulated by several researchers in the area of administration. However, we do not have an integrated view on how this theoretical articulation has been constructed and explored by Brazilian and foreign researchers. To fill this gap, this work aims to map and structure an integrative review of this theoretical articulation in the light of national and international literature. The work also points out the possible contributions of this theoretical articulation, research gaps and reveals that even in face of the appeals and the analytical potential evidenced by different researchers in the area of administration, this theoretical dialogue is in an embryonic stage.
tese
Estratégias de manejo de plantas daninhas em arroz de terras altas
(Universidade Federal de Lavras, 2026-08-19) Garcia, Dionatas Alex; Botelho, Flávia Barbosa Silva; Simão, Janine Magalhães Guedes; Carvalho, Alexandre Alves de; Gonçalves, Adenilson Henrique; Alecrim, Ademilson de Oliveira; Pereira, José Luiz de Andrade Rezende
Weeds are among the main factors limiting upland rice production, making the adoption of management strategies that ensure high control efficacy and crop selectivity essential. In this context, the objective of this study was to consolidate and expand knowledge on weed management in upland rice through a review article and a field experiment conducted over two growing seasons to evaluate different herbicide combinations. The literature review addressed the main aspects of weed management in upland rice, emphasizing the importance of integrating different control strategies to reduce weed interference and promote crop development. It also discussed the limitations resulting from the limited availability of herbicides registered for upland rice, highlighting the need for further research aimed at developing more efficient, selective, and sustainable management alternatives. The field experiment was conducted during the 2023/2024 and 2024/2025 growing seasons to evaluate different combinations of pre- and post-emergence herbicides for weed management. Herbicide treatments influenced several agronomic traits, particularly grain yield, crop phytotoxicity, days to flowering, severity of some diseases, and grain chalkiness, whereas milling yield and head rice yield were not affected. Combinations containing pendimethalin combined with bentazon provided high grain yield, adequate crop selectivity, and represented a promising alternative for the chemical management of upland rice. The results obtained expand knowledge on weed management in upland rice and contribute to improving management strategies by providing support for the development of more efficient, selective, and sustainable chemical management programs, with the potential to contribute to crop productivity.
dissertação
Qualidade nutricional e compostos bioativos em polpas e sucos de jerivá e juçara
(Universidade Federal de Lavras, 2026-06-17) Dias, Laryanne Lopes de Carvalho; Carvalho, Elisângela Elena Nunes de; Rodrigues, Luiz José; Araújo, Ana Beatriz Silva
The research was conducted in two studies. The first aimed to characterize the proximate composition, physicochemical, colorimetric, and nutritional parameters, bioactive compounds, antioxidant capacity, and microbiological quality of juçara pulp, as well as to investigate associations among these variables using Pearson’s correlation analysis. The pulp showed a high dietary fiber content (5.89 g.100 g⁻¹), low available carbohydrate content (1.68 g.100 g⁻¹), low sodium content (20.09 mg.100 g⁻¹), and vitamin C content of 7.88 mg.100 g⁻¹. Total phenolic compounds (141.57 mg GAE.100 g⁻¹) and anthocyanins (32.38 mg.100 g⁻¹) were detected, along with antioxidant capacity of 10.65 µmol Trolox.100 g⁻¹ (ABTS), 582.78 µmol Trolox.100 g⁻¹ (FRAP), and 351.20 mg ascorbic acid.100 g⁻¹ (phosphomolybdenum assay). The correlation analysis indicated that antioxidant activity results from the interaction among different bioactive constituents and food matrix characteristics. The second study evaluated changes resulting from the preparation of different jerivá-based formulations in terms of nutritional composition, bioactive compounds, antioxidant capacity, and microbiological quality. Compared with the pulp, the whole and sugar-added juices showed higher antioxidant capacity values, with differences of approximately 376% and 377% for ABTS, 231% and 283% for FRAP, and 59% and 317% for the phosphomolybdenum assay, respectively. The results highlight the nutritional, functional, and technological potential of juçara and jerivá, reinforcing the sustainable utilization of these native fruits and their application in the development of value-added food products.
dissertação
Proteases de Bacillus licheniformis no controle de organismos de importância na saúde única
(Universidade Federal de Lavras, 2026-07-03) Silva, Ana Carolina; Soares, Filippe Elias de Freitas; Carvalho, Geraldo Andrade; Chiaramonte, Josiane Barros
The control of agricultural pests, plant-parasitic nematodes, and disease vectors still relies heavily on chemical pesticides, whose continuous use has favored the selection of resistant populations and caused significant environmental impacts. In this context, the search for sustainable biotechnological alternatives has driven research into microbial enzymes with nematicidal and insecticidal potential. This dissertation aimed to evaluate the efficacy of proteolytic formulations derived from Bacillus licheniformis in controlling different organisms of One Health importance. Four studies involving nematodes, insect pests, and mosquito vectors were conducted. In the first study, the in vitro activity of the HPF protease against the nematodes Panagrellus sp., Meloidogyne incognita, Haemonchus spp., and Trichostrongylus spp. was evaluated. The results demonstrated high nematicidal activity, with up to a 100% reduction in the survival of M. incognita and a significant decrease in the populations of the other nematode species, highlighting the enzyme's potential to degrade the cuticle and body structures of these organisms. In the second study, three commercial protease formulations (APP1500, HPP, and HPF) were evaluated for the control of M. incognita in vitro and under greenhouse conditions. The enzymes exhibited high proteolytic activity under different pH and temperature conditions. Under greenhouse conditions, the formulations promoted reductions of more than 80% in the number of nematode galls and eggs. The third study investigated the larvicidal activity of the HPF formulation against Aedes aegypti larvae. Mortality was dependent on both concentration and exposure time, reaching 100% after 72 h at a concentration of 1.5% (w/v). Morphological analyses revealed severe damage to larval tissues, including leakage of visceral contents, confirming the proteolytic activity of the formulation. Finally, the fourth study evaluated the insecticidal effects of the APP1500 and HPF formulations against Spodoptera frugiperda, one of the major agricultural pests. Larval mortality increased as a function of concentration and exposure time, with ingestion treatments proving more effective than topical application. In addition, signs of an insect immune response were observed, including cuticular darkening associated with the melanization process. Overall, the results demonstrate that proteases derived from B. licheniformis exhibit a broad spectrum of biological activity against organisms belonging to different taxonomic groups. The observed mechanisms suggest that these enzymes promote the degradation of essential protein structures, compromising the integrity of the cuticle, eggs, and internal tissues of the target organisms. Therefore, the evaluated formulations represent promising alternatives for the development of sustainable bioproducts for the management of plant-parasitic nematodes, medically important vectors, and agricultural pests.