DSpace Collection:https://repositorio.ufu.br/handle/123456789/180532026-08-03T18:38:47Z2026-08-03T18:38:47ZExtratores de potássio em fontes alternativashttps://repositorio.ufu.br/handle/123456789/492472026-08-03T16:34:59Z2025-10-10T00:00:00ZTitle: Extratores de potássio em fontes alternativas
Abstract: To evaluate and develop new methods for determining potassium solubility in alternative fertilizer sources, a greenhouse experiment was conducted using pearl millet grown in two soil types: a Dystrophic Red Oxisol (Latossolo Vermelho distrófico) and a Typic Orthic Quartzipsamment (Neossolo Quartzarênico órtico típico). Twelve ground potassium-rich rock materials were applied at a rate equivalent to 600 mg K₂O dm⁻³ of soil. For comparison, a treatment with potassium chloride (KCl) as the standard fertilizer and an absolute control without potassium addition were included. All other nutrients were supplied in sufficient amounts to meet the crop requirements. The experiment was arranged in a completely randomized design with 13 treatments. Data were subjected to analysis of variance (ANOVA), and treatment means were compared using the Scott-Knott test at the 5% significance level. The fertilizer sources were analyzed using the following extraction methods: water (official method); 2% citric acid solution; neutral ammonium citrate (NAC); 2% citric acid + 0.5% ammonium fluoride solution; 5% tartaric acid solution; and 5% tartaric acid + 0.5% sodium fluoride solution (newly proposed methods). At the end of the pot experiment, the following variables were evaluated: soil-extractable potassium after cultivation, soil silicon content, pearl millet shoot dry matter, and the concentration and accumulation of calcium, magnesium, and potassium in plant tissue. Potassium uptake by the plants was correlated with the potassium recovery obtained by each analytical method. Among the evaluated extraction methods, the 2% citric acid + 0.5% ammonium fluoride solution showed the strongest correlation with plant potassium uptake and was therefore identified as the most suitable method for assessing insoluble potassium sources, followed by the neutral ammonium citrate (NAC) method2025-10-10T00:00:00ZDesempenho produtivo de um híbrido de milho, em resposta ao manejo de inseticidas foliares, em condições de segunda safra 2025https://repositorio.ufu.br/handle/123456789/491202026-07-28T06:21:14Z2026-03-23T00:00:00ZTitle: Desempenho produtivo de um híbrido de milho, em resposta ao manejo de inseticidas foliares, em condições de segunda safra 20252026-03-23T00:00:00ZAlterações em atributos físicos de sementes de tomate nanocondicionadas com óxido de zincohttps://repositorio.ufu.br/handle/123456789/490792026-07-25T06:27:45Z2026-03-13T00:00:00ZTitle: Alterações em atributos físicos de sementes de tomate nanocondicionadas com óxido de zinco2026-03-13T00:00:00ZÓleo essencial de manjericão na inibição do crescimento de Xanthomonas euvesicatoria pv. perforanshttps://repositorio.ufu.br/handle/123456789/490452026-07-24T14:28:06Z2026-03-11T00:00:00ZTitle: Óleo essencial de manjericão na inibição do crescimento de Xanthomonas euvesicatoria pv. perforans
Abstract: The use of essential oils as an alternative to the control of phytopathogens has shown promise in sustainable agriculture. This study aimed to evaluate the action of basil essential oil (Ocimum basilicum L.) in inhibiting the growth of the bacterium Xanthomonas euvesicatoria pv. perforans, the causal agent of bacterial spot in tomato. For the in vitro evaluation of bacterial growth inhibition, 19 accessions of basil oil at different concentrations (1, 0.1, and 0.01%) were used. The bacterial suspension was added to semi-solid 523 culture medium (0.8%) and poured into Petri dishes containing a basic layer (2% water-agar). After solidification of the medium, 6 sterile filter paper discs were distributed, to which 10 µL of oil were added at the different dilutions. Discs containing the antibiotic streptomycin (10 mg/mL) were used as a positive control. After 72 h, the diameter of the inhibition halo was evaluated. The essential oils A36442, A36444, A36445, A36446, and A36447 at a concentration of 0.01% showed antibacterial activity, demonstrating their potential as a control agent. It is concluded that basil essential oil can be a natural and sustainable alternative in inhibiting bacterial growth, contributing to the reduction of the use of chemical products.2026-03-11T00:00:00Z