Native Cerrado plants are exposed to soils with low pH and high availability of Al. In this study, we measured the Al content in adult plants, and investigated the effects of various Al doses on germination and early development of Eugenia dysenterica plants. For germination tests, the seeds were soaked in Al solution and evaluated for twenty days in growth chambers. In a second experiment, young plants were cultivated in hydroponic systems with various Al concentrations to evaluate the morphological, anatomical and physiological characteristics of E. dysenterica. Anatomical changes and low germinative vigor were observed in seeds germinated in 600 and 800 μmol Al³⁺ L⁻¹. In the hydroponic system, 200 μmol Al³⁺ L⁻¹ stimulated root growth in young plants. The activity of antioxidant enzymes and the accumulation of phenolic compounds were greatest at the highest Al doses, preventing changes in gas exchange and chlorophyll a fluorescence. Starch grain accumulation was noted in plant cells exposed to 200 and 400 μmol Al³⁺ L⁻¹. Adult E. dysenterica trees also accumulated Al in leaves, bark and seeds. These data suggest that E. dysenterica is tolerant to Al.

Measures of the apparent electrical conductivity (ECa) of soil are used in many studies as indicators of spatial variability in physicochemical characteristics of production fields. Based on these measures, management zones (MZs) are delineated to improve agricultural management. However, these measures include outliers. The presence or incorrect identification and exclusion of outliers affect the variogram function and result in unreliable parameter estimates. Thus, the aim of this study was to model ECa data with outliers using methods based on robust approximation theory and model-based geostatistics to delineate MZs. Robust estimators developed by Cressie-Hawkins, Genton and MAD Dowd were tested. The Cressie-Hawkins semivariance estimator was selected, followed by the semivariogram cubic fit using Akaike information criterion (AIC). The robust kriging with an external drift plug-in was applied to fitted estimates, and the fuzzy k-means classifier was applied to the resulting ECa kriging map. Models with multiple MZs were evaluated using fuzzy k-means, and a map with two MZs was selected based on the fuzzy performance index (FPI), modified partition entropy (MPE) and Fukuyama-Sugeno and Xie-Beni indices. The defined MZs were validated based on differences between the ECa means using mixed linear models. The independent errors model was chosen for validation based on its AIC value. Thus, the results demonstrate that it is possible to delineate an MZ map without outlier exclusion, evidencing the efficacy of this methodology.

O objetivo foi avaliar o efeito da suplementação ou não de 10 ppm de ractopamina em dietas para fêmeas suínas em fase final de terminação, sobre características de carcaça e qualidade de carne, foram utilizados 54 animais, com peso médio inicial de 98 kg (± 0,9 kg), distribuídos em delineamento inteiramente casualizado composto de dois tratamentos, 27 repetições e um animal por unidade experimental. Os tratamentos usados foram dietas sem ou com suplementação de 10 ppm de ractopamina, por 21 dias. A suplementação de ractopamina em dietas para fêmeas suínas na fase final de terminação influenciaram os parâmetros de características de carcaça e qualidade de carne dos animais. Foram observados efeito significativo (P0,05) para perda de água por cocção nos dias 1 e 7 e força de cisalhamento no dia 14. Com a adição de 10 ppm de ractopamina na dieta das fêmeas suínas em fase de terminação por 21 dias, obteve influência na qualidade de carne, proporcionando melhores parâmetros de características de carcaça, com maior rendimento de carne magra na carcaça.