Revista Ceres

Mycorrhization and glomalin in soil in integrated crop-livestock systems under variable nitrogen doses in pasture

Andréa Scaramal Menoncin — 2026-06-10

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 Nha-1, N90 and N180). Conducted in Ponta Grossa, Paraná, on soil transitioning from Cambisol Haplic Dystrophicto 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

Ethylene inhibitor, 1-methylcyclopropene, delays macauba fruit ripening and preserves oil quality

Osdneia Pereira Lopes — 2026-02-06

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 mesocarpand 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.

Moderate doses of selenium alleviate the effects of salt stress on the growth of eucalyptus seedlings

Ramon Negrão Santos Junior — 2026-06-16

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.

Lactofen and benzyladenine combined with phosphorus doses on the growth and productivity of soybean plants

Bruno Nogueira Forsan — 2026-07-10

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.

Physicochemical Properties of Monguba Seeds (Malvaceae fruit) at Different Ripening Stages

Lyvia Daim Costa — 2026-05-18

Pachira aquatica Aubl., popularly known in Brazil as Monguba, is an unconventional food plant (UFP) found in tropical regions of Central and South America. In the Amazon region, its seeds are traditionally consumed boiled, roasted, or fried and may also be incorporated into cakes and sweets. Despite this cultural use and the nutritional potential of its seeds, commercial exploitation remains limited. This study aims to assess physicochemical disparities between ripe and unripe Monguba seeds. In the physical characterization, the main differences were in the seeds: unripe seeds exhibited a higher mucilage content (1.3 g) and denser pericarp (4.5 g), while ripe seeds presented more pulp (12.9 g) and darker coloration. Chemically, ripe and unripe seeds contained high lipid and protein levels (35.6–32.5% and 13.0–12.7%, respectively). Ripe seeds showed an increase in carbohydrates (45.8%)
and minerals, like calcium (82.3 mg.100 g-1), magnesium (65.2 mg.100 g-1), manganese (1.4 mg.100 g-1), and zinc (2.1 mg.100 g-1), while unripe seeds showed higher acidity (23.9%) and lower °Brix (12.8). FTIR spectra revealed differences in polysaccharide hydrolysis and cell wall lignification during ripening. These findings emphasize the importance of exploring the various stages of plant development.

Urochloa ruziziensis and nitrogen fertilization in corn-bean production systems

Edson da Silva — 2026-08-03

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.

Wheat cultivars reared in nutritive solution screening towards aluminum toxicity tolerance

Christiane dos Santos Silva — 2026-08-03

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.

Emergence and initial growth of sesame under variations in irrigation water quality and proportion of plant ash

Elizeu Matos da Cruz Filho — 2026-01-19

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.

Reproductive studies in commercial cocoa tree

Pabliane Ramos Lawinscky — 2026-08-21

Theobroma cacao is a species of economic importance mainly for the food industry. The objective of the present study was to analyze pollen viability, stigma receptivity and controlled pollinations as a function of flower opening time (nine times, from 8:00 am to 4:00 pm) in selected plants of clones TSH1188 and CCN51. There was a higher average percentage of stigma receptivity except at the last collection time (4:00 pm). The clones showed a higher average percentage of pollen viability from 8:00 to 11:00 am. Fertilization percentage varied from 12.5 to 68.7% in clones throughout the flower opening time; a gradual trend in the fall in fertilization percentage was observed until 12:00 pm. Significant differences between clones for pollen viability and stigma receptivity were observed, indicating the influence of controlled pollination time on these characteristics.

Modulation of the droplet spectrum by working pressure, adjuvants, and herbicides

Cleyton Batista de Alvarenga — 2026-01-19

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.

Gaussian process regression as an alternative to kriging and SVM for spatial yield prediction

Vinicius Francisco Rofatto — 2026-03-16

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.

Agronomic performance of wheat cultivars under different plant density and planting times

Felipe Schwerz — 2026-03-16

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

Drift and deposition on coffee trees using a hydropneumatic sprayer at different application rates

Gustavo Moreira Ribeiro — 2026-07-31

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.

Spraying of phytosanitary products with different equipment and flow rates in soybean crop

Emanoel Rolim Farias da Silva — 2026-07-31

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.