DSpace Collection:

Deposição e eficácia da aplicação de calda herbicida com aeronave remotamente pilotada em função de taxas de aplicação e classes de gotas

Thu, 19 Feb 2026 00:00:00 GMT

Title: Deposição e eficácia da aplicação de calda herbicida com aeronave remotamente pilotada em função de taxas de aplicação e classes de gotas Abstract: Brazilian agriculture stands out on the global stage for its high productivity and increasing adoption of sustainable technologies. In this context, remotely piloted aircraft (RPAs) have emerged as a rapidly adopted technological innovation for the application of pesticides. However, several technical questions challenge farmers and professionals when it comes to herbicide application. This study aimed to evaluate the effects of application rate (10, 20, and 150 L ha⁻¹) and droplet size (medium and coarse) on the weed control efficacy of glyphosate + carfentrazone-ethyl applied using RPA equipped with rotary atomizers and a backpack sprayer. To this end, two field experiments were conducted in an area with high infestation of Ipomoea triloba, Alternanthera tenella, and Commelina benghalensis. Spray quality was characterized by evaluating the volumetric median diameter (VMD), relative span (RS), potential drift risk (PDR), droplet density (droplets cm-2), coverage (%), and deposition (µg cm-2). Weed control efficacy was determined by assigning field scores (3, 7, 14, 21, and 28 DAA). The results indicate that rotary atomizers produced droplets in the “Fine” and “Medium” classes. The application rate of 10 L ha-1 was equal to the rate of 20 L ha-1 in most evaluations, especially in Experiment 2. Applications with RPA (10 and 20 L ha-1) produced a VMD lower than 205,41 μm, while hydraulic nozzles (GRD 120015 and ULD 120015), used in ground applications (150 L ha-1), produced a VMD greater than 484,59 μm. In general, both application methods resulted in similar RA and droplet density. Aerial applications showed higher PDR (>24,94%) compared to ground applications (<1,66%). Ground applications (>23,52%) promoted higher coverage than aerial applications (<3,58%). Despite lower coverage, RPA promoted depositions similar to ground applications. In conclusion, RPA applications promoted high levels of control (> 90%), comparable to ground applications.

Qualidade e produtividade de alho-semente em função dos pontos de colheita e métodos de secagem

Thu, 12 Feb 2026 00:00:00 GMT

Title: Qualidade e produtividade de alho-semente em função dos pontos de colheita e métodos de secagem Abstract: Garlic (Allium sativum L.) is a crop of high economic importance that is vegetatively propagated; thus, its productivity and commercial quality depend directly on the quality of the seed garlic used. Determining the harvest stage and post-harvest management, particularly bulb drying methods, are key factors for maintaining the physiological and structural quality of propagative material and the productive performance of the subsequent generation. However, information regarding the interaction between these factors remains limited under Brazilian Cerrado growing conditions. Therefore, this study aimed to evaluate the influence of different harvest stages and drying methods on the productivity and quality of seed garlic (cv. Ito). The experiment was conducted in Rio Paranaíba, Minas Gerais, Brazil, using a randomized block design arranged in a 3 × 2 factorial scheme with five replications. Treatments consisted of three harvest stages (early, normal, and late) combined with two drying methods (natural curing by hanging and artificial drying). Biometric evaluations were performed at 50, 89, 110, and 134 days after planting, in addition to bulb classification based on diameter, skin integrity, and estimated yield. Harvest stage was the main factor associated with seed garlic performance, influencing dry matter accumulation, bulb physical integrity, and the distribution of commercial classes. Harvesting at normal and late stages increased the proportion of higher commercial classes (>6), which have greater economic value, and resulted in a higher proportion of closed bulbs, whereas early harvesting restricted bulb filling and increased the occurrence of open bulbs. The drying method showed a complementary effect, acting predominantly on bulb physical attributes and the maintenance of the structural quality of planting material. Artificial drying was more efficient for materials harvested early, reducing structural losses, while natural curing by hanging showed equivalent performance when associated with the normal harvest stage.

Potencial fisiológico e sanitário de sementes de soja tratadas com Trichoderma spp. no controle de Sclerotinia sclerotiorum

Thu, 19 Feb 2026 00:00:00 GMT

Title: Potencial fisiológico e sanitário de sementes de soja tratadas com Trichoderma spp. no controle de Sclerotinia sclerotiorum Abstract: The sanitary and physiological quality of soybean seeds is compromised by their association with Sclerotinia sclerotiorum, affecting the initial establishment of the crop and contributing to disease dissemination in the field. The objective of this study was to evaluate the effect of different inoculum potentials of S. sclerotiorum on seed quality, as well as the efficiency of biological control using Trichoderma. The experiment was conducted in a completely randomized design, arranged in a 5×5 factorial scheme, consisting of five inoculum potentials (0, 6, 12, 24, and 48 hours) and five control methods (three Trichoderma isolates, a chemical fungicide, and water).Sanitary quality was assessed by fungal incidence, and physiological quality was determined through germination, radicle protrusion, emergence, and seedling length tests, complemented by analyses of speed, uniformity, growth, and vigor indices. It was observed that increasing inoculum potential resulted in higher pathogen incidence and a progressive reduction in seed quality. Under higher inoculum pressure, the chemical fungicide was more efficient in maintaining physiological performance. The biological control agents showed variable effects depending on the isolate; however, overall, they were able to mitigate the effects of the pathogen at intermediate inoculum potential. It is concluded that increasing the inoculum potential of S. sclerotiorum increases pathogen colonization and incidence in seeds. The physiological quality of seeds is progressively reduced as inoculum potential increases, affecting germination, emergence, and vigor. The fungicide showed greater efficiency in control, whereas biological control with Trichoderma spp. is influenced by inoculum pressure.

Carbono orgânico do solo e estabilidade de agregados em latossolo sob diferentes usos no Cerrado, MG

Tue, 29 Jul 2025 00:00:00 GMT

Title: Carbono orgânico do solo e estabilidade de agregados em latossolo sob diferentes usos no Cerrado, MG Abstract: Inadequate soil management systems reduce aggregate stability, compromising soil organic carbon, soil structure, agricultural productivity, and environmental balance. The objective of this study was to evaluate the stability of aggregates under different cropping systems and soil depths, and to relate this stability to the total organic carbon (TOC) content of Oxisols in the Cerrado biome. The land use types were considered treatments, and soil samples were collected from a farm in the rural area of Uberlândia, Minas Gerais, Brazil, under the following four management systems: (i) native Cerrado vegetation (T1); (ii) a no-tillage system (T2); (iii) conventional tillage system (T3); and (iv) an irrigated grain cropping system (T4). Samples were collected at four depths (0–10, 10–20, 20–40, and 40–60 cm), with four replicates in each system. Four trenches were dug to the targeted depths for sampling. The samples were analyzed for aggregate stability and the aggregate stability index (ASI). The aggregate fractions were examined based on the mesh size of the sieves used (2 mm, 1 mm, 0.5 mm, and 0.25 mm). Additionally, the total organic carbon (TOC) content was determined for each aggregate class. The results were analyzed using an analysis of variance, and the means were compared using Dunnett’s test and Pearson’s correlation. The no-tillage system produced the best results in terms of aggregate stability and TOC levels, surpassing even the native Cerrado in some layers. These results underscore the importance of maintaining vegetation cover and avoiding soil disturbance in order to preserve the soil´s physical and chemical quality. Among intensive systems, conventional tillage caused less degradation than central pivot irrigation. TOC proved to be a good indicator of soil quality, but it should be interpreted alongside other attributes. Conservation practices are essential for the sustainability of Oxisols in the Cerrado.