DSpace Collection:

Comportamento espacial dos atributos fisiológicos de sementes de soja de um campo de produção

2026-03-25T06:21:12Z

Title: Comportamento espacial dos atributos fisiológicos de sementes de soja de um campo de produção Abstract: Soybean seeds may exhibit distinct quality levels when produced in different management zones. This study aimed to evaluate the physiological attributes of soybean seeds and identify their variability and spatial distribution using geostatistical tools. Data were collected at the Glória Farm (Uberlândia, MG) and analyzed at the Seed Analysis Laboratory of the Federal University of Uberlândia (Umuarama Campus). Soybean seeds were harvested from 48 georeferenced points to determine their physiological behavior and spatial dependence patterns. The variability of physiological quality attributes from different zones was assessed through germination, accelerated aging, seedling emergence, electrical conductivity, and seedling length tests. Previously analyzed soil attributes, along with initial plant stand and seed yield, enabled the validation of management zones. Physiological seed quality is not uniformly distributed across the production field; therefore, geostatistics is an effective tool for determining the spatial distribution of physiological quality attributes in soybean seed production areas.

Índice NDVIe sua correlação com a produtividade do café

2026-03-05T06:20:09Z

Title: Índice NDVIe sua correlação com a produtividade do café Abstract: Precision agriculture has become an important tool in modern farming, enabling increased productivity, cost reduction, and environmental sustainability. In this context, this study aimed to evaluate the relationship between the Normalized Difference Vegetation Index (NDVI) and the productivity of Arabica coffee (Coffea arabica L.). The research was conducted in a cultivar coffee irrigated area of approximately 27 ha, located in the municipality of Indianópolis, Minas Gerais, Brazil, using a sampling grid composed of 50 georeferenced points. Productivity was determined through manual harvesting of selected plants at each point, followed by drying and processing. NDVI indices were obtained from Planet satellite images, covering the period from August 2023 to July 2024. The data were statistically analyzed using descriptive analysis and Pearson's linear correlation, as well as spatial interpolation by kriging to generate productivity maps. A moderate positive correlation was observed between NDVI obtained in December 2023 and final coffee productivity, whereas NDVI from March 2024 showed a negative correlation, reflecting physiological differences of the crop throughout its growth cycle. It is concluded that NDVI can be used as an auxiliary tool for estimating coffee productivity, provided that the timing of image acquisition is considered, with greater efficiency during periods of higher vegetative activity.

Atributos físicos e sensoriais do grão do café e seu comportamento espacial

2026-03-04T06:26:24Z

Title: Atributos físicos e sensoriais do grão do café e seu comportamento espacial Abstract: Arabica coffee (Coffea arabica L.) represents one of the most economically and socially relevant crops in Brazil, with beverage quality being an essential factor for its commercial value. This study aimed to evaluate the spatial variability of the physical attributes of coffee beans and the sensory attributes of the beverage, seeking to identify patterns and relationships between them. The research was conducted in a 27-hectare field at Fazenda Mandaguari, in Indianópolis-MG, cultivated with the Topázio cultivar under irrigation, where a grid of 50 georeferenced points was established for field attribute sampling. Based on data of altitude, soil attributes, and grain yield, zones of different potentials or homogeneous zones (HZ) were defined. In the laboratory, the manually harvested coffee beans, subjected to natural drying, were physically classified according to Normative Instruction No. 8/2003, with sieve analysis, defects evaluation (black, sour, green, bored, shell, and shell center beans), and coffee type classification. Subsequently, sensory analysis was performed following the Specialty Coffee Association (SCA) protocol, conducted by Q-Graders, in the four zones of different potentials previously defined. The data were analyzed using descriptive statistics and geostatistics, resulting in thematic maps of the spatial distribution of the evaluated attributes. The results revealed significant variability among the zones, with Zone 3 standing out for achieving the highest sensory score (84.5 points), related to a higher proportion of beans retained in larger sieves (16 and 17) and lower occurrence of defects. On the other hand, Zone 4 showed the lowest sensory score (80.25 points), associated with a higher frequency of defects and predominance of smaller beans. The combined analysis showed that, although some defects such as green and black beans were present, positive attributes of body, aroma, and balance compensated for their effects in certain zones, allowing the achievement of superior beverage quality. Thus, the integration of physical and sensory attributes, combined with the use of Precision Agriculture tools, demonstrated that there is spatial variability in coffee quality for some attributes, reinforcing the potential of site-specific management strategies to add value to the product.

Avaliação de cinco calcários em diferentes granulometrias na cultura do sorgo

2026-02-12T06:20:59Z

Title: Avaliação de cinco calcários em diferentes granulometrias na cultura do sorgo Abstract: Soil acidity in tropical and subtropical regions poses a challenge to agricultural productivity, especially due to the presence of toxic aluminum and deficiencies in calcium (Ca) and magnesium (Mg). Liming is a widely used practice to address this situation, correcting soil acidity, providing calcium and magnesium to plants, promoting root development, and thus favoring nutrient absorption. This study aimed to evaluate the effect of different types of limestone, with varying particle sizes, on sorghum (Sorghum bicolor (L.) Moench) grown in a greenhouse. The experiment was conducted at the Federal University of Uberlândia (UFU), in Uberlândia-MG, using a completely randomized design (CRD) in a 5x5 + 1 factorial scheme, with four replications. Five types of soil amendments with different CaO and MgO contents were evaluated (44.23% CaO and 7.68% MgO; 31.73% CaO and 20.26% MgO; 55.58% CaO and 1.84% MgO; 34.62% CaO and 23.79% MgO; 46.17% CaO and 13.44% MgO) and five particle size ranges (<0.297; 0.297-0.500; 0.500-0.840; 0.840-1.000 and 1.000-1.700 mm). The variables analyzed included shoot dry weight, calcium and magnesium content in the plant and soil, soil pH (in water and CaCl₂), potential acidity, and base saturation. The data were subjected to statistical analysis using Tukey's and Dunnett's tests at a 5% significance level, using RStudio software. The results demonstrated that the corrective with 44.23% CaO and 7.68% MgO provided the highest levels of foliar calcium, while the limestone with 31.73% CaO and 20.26% MgO resulted in the highest levels of magnesium in the soil in particle diameters <0.297 mm and 1.000-1.700 mm, in addition to foliar magnesium, which obtained superior results in particles smaller than 1.0 mm. Thus, it is concluded that both the type of limestone and its particle size significantly influence the nutrient dynamics in the soil and the development of the sorghum crop.