ABSTRACT The use of spraying drones in agricultural crops has become a recurring practice on rural properties. In this context, this study aimed to evaluate the influence of different spraying equipment and flow rates on the agronomic performance of second-season soybean crop. The experiment was conducted in the experimental area of the Polytechnic College, Federal University of Santa Maria, under the experimental design of randomized blocks, in a 3×2 factorial, with three spraying equipment (DJI T16 drone, DJI T40 drone and MF 8225 self-propelled sprayer) and two flow rates for each equipment (10 and 15 L ha-1 for drones and 50 and 100 L ha-1 for self-propelled sprayer). For drones, application rates of 10 and 15 L ha-1 were classified as low and high, respectively, whereas for the self-propelled sprayer, application rates of 50 and 100 L ha⁻¹ were classified as low and high, respectively. The evaluated variables were number of pods per plant, number of grains per plant, thousand-grain weight, and grain yield. ANOVA indicated no significant interaction between application rates × equipment, with no significant main effects observed. It was concluded that both drones and the self-propelled sprayer, regardless of the application rate, ensured similar soybean crop performance.
ABSTRACT Aluminum present in acidic soils hinder plant development and growth, while impacting grain productivity in susceptible wheat cultivars. The objective of this study was to evaluate aluminum toxicity tolerance in commercial wheat cultivars reared in a nutritive solution. The experimental design was completely randomized with four repetitions. The treatments were arranged following a split-plot, with a total of 12 wheat genotypes reared in a nutritive solution that contained Aluminum and one which was absent of Al. The wheat seedlings were maintained in a climate-controlled chamber, at 23°C ± 1 ºC, with constant photoperiod and aeration. After 96 hours, the following characteristics were evaluated: root number (RN), shoot length (SL), longest root length (R1), second longest root length (R2) and sprout dry mass (DM). Variance analysis was performed on the data and the means were classified utilizing Scott & Knott (5% significance). The results revealed the genetic variation between the cultivars, highlighted was the cultivar ORS Ágile which was sensitive towards aluminum, just as the sensitive witness Anahuac 75. The cultivar BRS Atobá demonstrated greater tolerance, as did BRS Sabiá and TBIO Sossego.
ABSTRACT Evaluated the effect of Urochloa ruziziensis in association with nitrogen fertilization, in a second-crop corn and bean cultivation system. The experiment used a no-till planting system (NTPS). The treatments consisted: second-crop corn in association with U. ruziziensis and exclusive corn cultivation. Five doses of N (0, 25, 50, 75, and 100 kg ha-1) were used in the subplots. After corn cultivation, the plots were desiccated with glyphosate, and then bean cultivation was carried out. In the bean experiment, the treatments consisted of the absence and presence of U. ruziziensis straw from the previous crop in the plots. In the subplots, five doses of N (0, 15, 30, 45, and 60 kg ha-1) were used. The cultivation of U. ruziziensis at a density of 3 kg ha-1 in consortium with corn, second crop, in no-till, increases the amount of plant residues on the soil surface and does not alter the productivity and production components of corn and beans grown in succession. In the corn and U. ruziziensis intercropping system, it is not necessary to alter the N topdressing rate compared to the exclusive cultivation of corn.
ABSTRACT In this study, we aimed to evaluate the effects of the growth regulators lactofen and benzyladenine, combined with phosphorus doses, on soybean cultivation. Soybeans with an average harvest cycle of 134 days were used. The design was a randomized block factorial scheme with 12 treatments: growth regulators (control, lactofen herbicide 600 ml ha-1, and benzyladenine hormone 150 ml ha-1) and phosphorus doses (control, 75, 100, 120 kg ha-1), with three replicates. The following parameters were evaluated: number of productive nodes, number of pods, grains per pod, grain productivity, weight of 1000 grains, shoot dry mass, and root dry mass. The use of benzyladenine resulted in higher values for the number of nodes, shoot dry mass, root dry mass, and grain productivity than lactofen and the control, regardless of the phosphorus dose used. The variables analyzed generally responded linearly to phosphorus doses, and applying 120 kg ha-1 of P2O5 generally provided the best results. We recommend the use of benzyladenine, together with a phosphorus dose of 120 kg ha-1, to improve soybean productivity.
ABSTRACT Although selenium (Se) is not essential for plant metabolism, low Se concentrations can enhance tolerance to abiotic stress. This study evaluated the effects of exogenous Se (1, 5, and 25 μM) on two eucalyptus genotypes (VCC 865 and AEC 0144) under saline stress (100 mM NaCl). Growth, biomass, gas exchange, ion accumulation (K+, Na+, Ca2+), and pigment content were analyzed. Salinity significantly impaired physiological performance, reducing height, stem diameter, net photosynthesis (PN), transpiration (Tr), and stomatal conductance (gs), while increasing Na+ in roots and leaves. Se at 1 and 5 μM mitigated these effects, particularly by reducing Na+ accumulation. VCC 865 showed increased K+ in roots and decreased Na+ in shoots with 1 μM Se, while AEC 0144 displayed improved ionic balance in roots and leaves. The chlorophyll pigment content remained unchanged between the treatments. However, 25 μM Se intensified salinity damage, indicating the importance of dose optimization. Photosynthetic parameters were sensitive indicators of Se-mediated responses. Therefore, the targeted use of selenium represents a promising strategy to improve seedling establishment in environments affected by salinity, contributing to the development of more resilient forest systems and the expansion of areas suitable for production.
Spraying is essential for applying nutrient solution and phytosanitary treatments, necessitating efficient deposition on the target areas. However, during application, some of the spray solution drifts into the environment. Therefore, understanding the effectiveness of spraying equipment is crucial to reduce losses. This study aimed to evaluate spray deposition on leaves and drift above the canopy, on the soil, and on leaves in rows adjacent to the target area using a hydropneumatic sprayer at different application rates. The JA1 and MAG2 nozzles were used to spray 200 and 400 L ha-1, respectively. Deposition was evaluated by incorporating a marker into the solution and subsequently analyzing it via spectrophotometry. The assessment covered included four adjacent rows on each side of the sprayer. The application rate, side, and row were used to fit a linear mixed model, with the means being compared using the Tukey test with Šidák correction. All parameters exhibited greater deposition on the left side compared to the right, with increased deposition on the right side only occurring due to a wind direction. Drift was detected on the soil, above the canopy, and up to the fourth assessed row, influenced by application rate, wind direction, and droplet classification.
ABSTRACT Integrated crop-livestock systems (ICLS) are recognized for their ecological and socioeconomic benefits, particularly for nutrient cycling efficiency and biodiversity promotion. This study assessed arbuscular mycorrhizal fungi (AMF) populations and soil glomalin concentrations, and the productivity of corn and pasture in crop-livestock (CL) and crop-livestock-tree (CLT) systems, fertilized with two nitrogen (N) doses in pasture (90 and 180 kg N ha-1, N90 and N180). Conducted in Ponta Grossa, Paraná, on soil transitioning from Cambisol Haplic Dystrophic to Dystrophic Red Latosol, samples were collected for microbiological analysis after pasture and corn cycles. The study measured easily extractable glomalin (EEG), total glomalin (TG), AMF sporulation, and root colonization, along with corn yield and pasture biomass. Results indicated that the CL system promoted higher EEG than CLT after both cycles, with N90 showing higher glomalin levels post-pasture. AMF sporulation increased with the CL N180 treatment after corn, while no differences were found in AMF root colonization across systems and N levels. Corn yield and pasture biomass were also higher in CL compared to CLT. Findings suggest that CL systems with proper N fertilization enhance AMF and soil glomalin, and agricultural productivity, supporting soil quality and sustainability.
ABSTRACT Wheat plays a critical role in global food security and the agricultural economy. In Minas Gerais, Brazil, one of the major challenges for wheat production is the high variability of meteorological conditions. Therefore, studies that support wheat producers in defining more accurate sowing dates and plant densities according to cultivar requirements are essential, as they can contribute to increasing yield and enhancing agricultural resilience. The aim of this study was to evaluate the response of wheat cultivars, based on growth, micrometeorological, and yield-related traits, under different sowing times and plant densities. The experiment was conducted during the autumn–winter growing season of 2022 in an experimental area located in Ijaci, Minas Gerais, Brazil. Four wheat cultivars were evaluated under different sowing times and plant densities. Agronomic and agrometeorological variables were monitored throughout the field experiment. The results showed that wheat sown within the recommended sowing window exhibited superior performance, benefiting from greater soil water availability, higher growth rates, and increased radiation interception. Grain yield was, on average, 37.9% higher under normal sowing conditions compared with late sowing, confirming the strong influence of sowing time on crop performance. No significant differences were observed among cultivars or plant densities. These findings provide relevant guidance for producers and reinforce sowing time as a key factor for efficient wheat management.
ABSTRACT The macauba palm produces high-quality oil, with oil content in the fruit potentially increasing after harvest. However, storage limitations due to microorganism and metabolism deterioration restrict the fruit's shelf life. This study evaluated the effects of the ethylene inhibitor 1-MCP on the physiological, physical, and chemical characteristics of macauba palm fruits, focusing on oil quality preservation during storage. Various concentrations of 1-MCP (0, 1000, 2000, and 3000 nL L-1) were applied over two exposures (12 and 24 hours) times during fruit storage, assessed at six intervals. Untreated fruits exhibited damaged mesocarp and spoilage by the end of storage, while 1-MCP treatment notably suppressed spoilage. The inhibitor reduced respiration and ethylene production throughout storage, although it did not completely prevent climacteric peaks of CO2 and ethylene, which lessened with higher 1-MCP concentrations. Additionally, 1-MCP delayed ripening, reflected in slower accumulation of total soluble solids and reduced mesocarp firmness loss. Treated fruits showed smaller increases in mesocarp oil content during storage, and the inhibitor also slowed oil acidification. Overall, the responses in all parameters improved with higher 1-MCP concentrations, indicating that 1-MCP could be an effective post-harvest strategy for maintaining the quality of macauba palm fruits and their oil.
ABSTRACT Under saline conditions, the seed germination process is often impaired. Thus, the use of organic residues may represent an alternative to mitigate salt stress in plants. This study aimed to investigate sesame seed germination and early growth, considering the influence of irrigation water quality and the proportion of plant ash in the substrate. Conducted at the Federal Rural University of Pernambuco, the experiment tested different proportions of sugarcane bagasse ash [0%, 13%, 26%, 40%, 54%] and irrigation water qualities (0.3, 1.8, and 4.1 dS m-1). The ashes did not mitigate the effects of irrigation water salinity, and their increase had negative effects on emergence percentage. However, an ash proportion of up to 13.7% increased the emergence speed index when non-saline water (0.3 dS m-1, control) was used, but under saline water conditions, it caused detrimental effects. Average emergence time and average emergence speed showed positive results with ash proportions up to 21% when non-saline water was used. Plant height, stem diameter, and root length were negatively affected by higher ash proportions in the substrate, especially under irrigation with saline water.
ABSTRACT Detecting spatial yield variability is essential for precision agriculture because it minimizes environmental impact and enhances economic returns. This study proposes Gaussian Process Regression (GPR) as a predictive model for yield estimation, particularly in cultivated areas where the highest yields appear in the central region of the field, while the edges exhibit lower productivity. The study was conducted in Patos de Minas, Brazil, using 795 georeferenced soybean yield samples over 3.7 hectares. The analysis evaluates GPR across different sample sizes and compares it with Ordinary Kriging (OK) and Support Vector Machine (SVM). The results indicate that GPR and OK perform similarly under high sampling densities, but GPR achieves higher predictive accuracy under low-sampling conditions. A sample size of at least 60% of the full dataset is necessary to maintain reliable spatial prediction, as smaller sample sizes lead to greater prediction errors and less defined spatial patterns. SVM, in contrast, produces a smoothing effect across all sampling densities, which reduces its ability to capture local variations. These findings highlight GPR as a robust alternative for yield mapping, particularly in scenarios with limited data availability. From a practical perspective, GPR and OK remain strong candidates for yield prediction, reinforcing the importance of model selection based on data availability and spatial variability.
ABSTRACT The droplet spectrum is a crucial factor in optimizing herbicide efficacy and minimizing spray drift. This study evaluated the effects of working pressure (100 to 600 kPa) and six adjuvants on droplet size, both in the absence and presence of herbicides, using an air-induction nozzle (TTI 110015VP) and a particle analyzer. Higher working pressures reduced droplet size – measured as Dv0.1, Dv0.5 (volume median diameter), and Dv0.9, representing the diameters at which 10%, 50%, and 90% of the total spray volume consists of droplets of that size or smaller – and increased the volume percentage of fine droplets (V100), regardless of the adjuvant or herbicide. Adjuvants influenced the droplet spectrum, with Xtend Protect1 significantly reducing Dv0.9. However, the lowest relative span, indicating greater droplet size uniformity, was achieved by different adjuvants depending on the working pressure. A significant interaction between herbicides and adjuvants was observed, underscoring the need for a comprehensive analysis of these variables to optimize application quality. The addition of adjuvants and herbicides to the spray solution altered the correlations between droplet spectrum variables, emphasizing the importance of considering multiple factors in application decisions. Selecting the appropriate working pressure and adjuvant, along with a thorough analysis of the droplet spectrum, is essential for effective weed control, reducing spray drift, and ensuring environmental, applicator, and consumer safety.
Our goal was to evaluate the bioherbicide effect of ethanol extract and its fractions of increasing polarity derived from the leaves of Clusia fluminensis, on the germination and initial growth of Lactuca sativa (lettuce) and Megathyrsus maximus (guinea grass), as well as their activity in the catalase, peroxidase, and superoxide dismutase enzymes. For the antioxidant capacity, the DPPH, ABTS, FRAP and phosphomolybdenum tests were used, in addition to the pigment content analysis. Chemical analyses were performed by quantification of total phenol, tannin, and flavonoid contents. The ethyl acetate fraction showed the best result, at concentration 0.75mg/mL, with less influence on lettuces seeds and greater influence on guinea grass seeds. In treatments with ethyl acetate fraction, there was a significant increase in the activity of the three enzymes in lettuce seeds, up to 67% in catalase. The catalase and dismutase enzyme activity decrease in 30% and 19%, respectively in guinea grass seeds. The presence of total phenols, tannins, and flavonoids on the ethyl acetate fraction allow a correlation to the most significant antioxidant activity by the ABTS, DPPH and FRAP assays. The results, therefore, suggest that the ethyl acetate fraction from leaves of C. fluminensis showed phytotoxic potential.
ABSTRACT A novel beverage combining mate tea (Ilex paraguariensis) and pitanga pulp (Eugenia uniflora), a native Brazilian fruit, was developed to highlight local ingredients and create a healthy food product. Four formulations with varying proportions of mate tea and pitanga pulp were evaluated (F1: 100% mate tea, F2: 90% mate + 10% pitanga, F3: 80% mate + 20% pitanga, F4: 70% mate + 30% pitanga). Physicochemical, sensory, and color analyses were conducted, including parameters such as L*, a*, b*, Hue, chroma (C*), total phenolic content (TPC), and antioxidant capacity (TEAC). The addition of pitanga significantly altered the beverage’s color, making it darker and redder, and enhanced sensory attributes by reducing bitterness and astringency. Formulation F2 achieved the highest sensory acceptance, offering a balanced flavor profile. While F1 had the highest TPC and TEAC values, pitanga addition slightly decreased these metrics without compromising the beverage's antioxidant properties. Principal Component Analysis (PCA) revealed that sensory acceptance strongly correlated with flavor and sweetness, while physicochemical attributes such as antioxidant capacity had limited influence. The combination of mate tea and pitanga pulp provides an innovative, functional beverage with a sustainable profile, balancing health benefits and consumer preferences, particularly in the F2 formulation.
ABSTRACT Tamarind is a tropical fruit highly cultivated in some countries. In Brazil, still there is a little exploitation of tamarind fruits, but its characterization can subsidize the commercial exploitation. Fruit characterization enables the study of genetic diversity between matrices or populations, allowing the identification of possible genitors, or even genotypes with superior characteristics. The aim of this study was to characterize and evaluate the genetic diversity of the physical characteristics of tamarind fruit, in order to provide subsidies for genetic improvement programs and conservation of the species. The fruits were evaluated by weight, diameter and length, color of epidermis and pulp. A completely randomized design was adopted, with 4 treatments (plants) and 7 replicates of 10 fruits, totaling 280 fruits. The data were subjected to analysis of variance, and the means were compared using the Duncan test. The matrix 4 presented higher values of weight, length and diameter, when compared to the others. There is genetic diversity among the tamarind matrices. Two groups were formed using the dendrogram generated by the UPGMA method. A strong correlation was observed between fruit length and weight, peel weight and fruit weight, and peel weight and length, which is crucial information for genetic improvement.
ABSTRACT The use of unmanned aerial vehicles imagery has become an established practice in high-throughput phenotyping for predicting the yield potential of maize (Zea mays L.), although applying these technologies presents challenges due to regional specificities. This study aimed to assess the effectiveness of RGB (red, green, and blue) aerial imagery for the early identification of yield maize genotypes during the vegetative stage. Four genotypes were evaluated using a randomized block design with four replications. The experiment involved seven flights at two heights. Twenty-nine RGB vegetation indices were derived from image processing to discriminate genotypes based on plot-level grain yield. Nested models were fitted to predict temporal Best Linear Unbiased Predictions (BLUPs), with the most repeatable indices selected for analysis. Significant differences were observed among genotypes and plant spacing. The optimal flight timing was identified as 43 days after planting at a height of 80 meters. The indices MRCC, RmB, and RCC exhibited the highest repeatability and showed strong correlations with grain yield, demonstrating potential for RGB-based phenotyping studies. These findings highlight the utility of RGB imagery as a tool for early maize genotype selection, enhancing efficiency and accuracy in breeding programs and contributing to advancements in precision agriculture.
Lecythis tuyrana, Eschweilera coriacea, and Clathrotropis brunnea are three species with high forestry and nutraceutical potential for restoring the Magdalena River Basin in the Anden region of Colombia. The study aimed to establish a baseline for producing high-quality seedlings with these species under nursery conditions. In independent experiments for each species, the treatments consisted of a factorial combination of three substrates formulated with local soil (LS), vermicompost (VC), pine bark (PB) or rice husk (RH), and three doses of a 6-month controlled-release fertilizer (CRF). In general, substrates, the addition of CRF up to 8 g L-1 or its interaction had little influence on the growth, biomass, and quality of L. tuyrana and C. brunnea seedlings. The combination of S2 substrate (40% LS + 20% VC + 40% RH) + 5 g L-1 produced E. coriacea seedlings with 1.6 times more total biomass than unfertilized seedlings. Despite being 23% more expensive than the local substrate, this substrate has a more acceptable pH, bulk density, and nutrient contents. The importance of selecting the appropriate dose of CRF among tree species of the same biome is highlighted.
The objective of the study was to evaluate Conilon coffee seedlings treated with a systemic insecticide and a humic substance, both of which have growth-promoting functions. The experiment was conducted in a commercial nursery for the production of Conilon coffee seedlings in the municipality of Linhares, Espírito Santo, Brazil. The experimental design was a randomized block in a 2 x 3 factorial scheme with four replicates. Two clones, A1 and K61, were used, and treatments included the use of insecticides alone or in combination with humic substances. Characteristics of roots, shoots, leaves, and cuttings of Conilon coffee seedlings were evaluated. The combined use of insecticides and humic substances resulted in increases of 39.0%, 47.8%, and 20.5% in shoot length, leaf area, and root volume, respectively, compared to the control. Superior production of leaf and aerial biomass was also observed in clone A1 due to the use of the insecticide in combination with the humic substance. It was concluded that clone A1 has better seedling growth compared to clone K61 and that the use of insecticide in combination with humic substances is recommended for the production of Conilon coffee seedlings.
The use of plant growth regulators is a widely adopted strategy to optimize germination and propagation under in vitro conditions; however, their application can also cause morpho-physiological changes in plants that need to be investigated. The study aimed to evaluate the effect of gibberellic acid (GA) and 6-benzyladenine (BA) supplementation on the in vitro germination, structure, and shoot proliferation of S. undatus, as well as to test different substrates during the acclimatization of the obtained plantlets. Seeds were inoculated in MS medium without plant growth regulators (MS0) and in MS medium supplemented with GA (1.0 and 3.0 mg L-1) and BA (1.0 and 2.0 mg L-1). Seeds were also germinated under ex vitro conditions as a control. In vitro culture conditions accelerated germination and initial development of S. undatus. However, GA supplementation did not influence seed germination speed. Greater hypocotyl and epicotyl lengths were obtained in plants grown in a medium supplemented with 1 mg L-1 GA. Regardless of the concentration, BA led to the emergence of multiple axillary shoots, altering seedling architecture. Furthermore, BA and GA acted antagonistically on the morphoanatomy of the hypocotyls, increasing and decreasing the thickness of this organ, respectively. The treatments supplemented with BA regenerated twice the number of plantlets per seed. The commercial substrate allowed a higher survival rate (~85%) of the plantlets compared to sand (~30%), and it has been recommended for acclimating S. undatus plantlets obtained through in vitro propagation.
