Acta Scientiarum. Agronomy

Hygroscopicity and thermodynamic properties of grains of Moringa oleifera L.

2025-10-21T17:48:44+00:00

The Moringa plant, widely recognized for its uses in both animal and human nutrition as well as in medicine, has seeds rich in oil and protein. For their maintenance and processing, safe storage conditions are needed, in addition to an understanding of the energy required for this process. The objective of this work was to study the hygroscopic and thermodynamic properties of moringa grains. The static gravimetric method was used at temperatures of 20–70°C and relative humidities of 10.75–85.11%. Nine mathematical models were fitted to the experimental water sorption data. The modified Halsey model provided the best fit, with an R² of 97.72%, P of 6.71%, and SE of 0.01, and was therefore used to calculate the thermodynamic properties. An increase in the equilibrium water content from 0.039 to 0.162 (db) resulted in a decrease in the energy released during adsorption (Q_st) from -3613.589 to -2453.029 kJ kg^-1, the differential entropy (∆S) from -2.519 to -0.115, and Gibbs free energy (∆G) from -351.897 to -21.773. This process was considered spontaneous.

A comparative study of automatic guidance signals and planting speeds for corn

2025-10-21T17:48:48+00:00

Planting is considered one of the most critical mechanized agricultural operations, because any errors during this stage could cause significant yield losses. In this context, the use of automatic guidance systems can minimize errors in the row parallelism and alignment, ensuring consistent spacing and optimal operational speeds. Therefore, the objective of this study was to evaluate the effects of different GNSS correction signals and forward speeds on the corn planting. The treatments consisted in two GNSS correction signals for automatic guidance: SF1 – a free-to-use signal with ±23 cm pass-to-pass parallelism error, and SF2 – a subscription-based signal with ±5 cm pass-to-pass parallelism error; and three forward speeds (5, 6, and 8 km h^-1). The depth and longitudinal seed distribution (classified as double, skipped, and acceptable spacings) were evaluated using statistical process control (SPC) and descriptive statistical methods. The results showed that the SF2 signal provided superior seeding quality, characterized by lower variability and enhanced process stability. Therefore, usage of the subscription-based SF2 signal is recommended to achieve optimal seeding quality. It improves the seed distribution and link to acceptable parallelism correction.

Essential oil of Citrus aurantium var. dulcis: A new approach to control Diatraea saccharalis and Spodoptera eridania larvae

2025-10-21T17:48:50+00:00

Studies focusing on the potential use of botanical insecticides have increased significantly in recent years. Essential oils extracted from citrus fruit peels contain limonene, a monoterpene that is widely used in agricultural pest control studies. This study aimed to investigate the insecticidal properties of the essential oil of Citrus aurantium (L.) var. dulcis and analyze its effects on the midgut of Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) and Spodoptera eridania (Stoll, 1782) (Lepidoptera: Noctuidae) neonate larvae. After essential oil dilution, five concentrations (0.06; 0.12; 0.25; 0.50 and 1.00%) were obtained and topically applied to the prothorax of larvae. Behavioral observations and larval mortality data were recorded every 24h for a duration of 120h. Midgut samples were collected 24 and 48h after the bioassays to perform histological and ultrastructural analyses. Both species exhibited low mobility, which progressed to paralysis after treatment, and mortality was only recorded in the first 48h. D. saccharalis and S. eridania larvae treated with 1.00% essential oil concentration had mortalities of 89 and 47%, respectively. The lethal concentrations (LC₅₀) of essential oil have been estimated to be 0.50% (CI = 0.45–0.57%) for D. saccharalis and 1.06% (CI = 0.89–1.35%) for S. eridania. The histological and ultrastructural analyses revealed significant midgut damage, such as detachment of the muscle fibers from the basal region of the epithelium and spacing of columnar cells, which progressed to a complete degeneration of the epithelial cells. The negative effects of C. aurantium var. dulcis essential oil on D. saccharalis and S. eridania neonate larvae indicate its bioinsecticide potential. Our results suggest that this essential oil can be implemented in integrated pest management for sustainable crop production.

Fuzzy logic in the simultaneous selection of quantitative and qualitative descriptors for kale

2025-10-21T17:48:54+00:00

Simultaneous selection in genetic improvement presents difficulties in selecting qualitative traits as well as the desired commercial ranges for quantitative traits. Thus, fuzzy logic has become an alternative, enabling the computational modelling of the researcher’s experience. This study aimed to assess the efficiency of fuzzy logic in simultaneous selection considering both qualitative and quantitative descriptors. The developed methodology was applied to data from two experiments with kale half-sibs. The first experiment was carried out in Viçosa in randomised blocks, with 24 families of kale half-sibs, 4 replications, and 5 plants per plot. The second experiment was carried out in Montes Claros in randomised blocks, with 36 kale genotypes, 33 families of half-sibs, and 3 commercial cultivars, with 4 replications and 6 plants per plot. Quantitative and qualitative traits were evaluated, and individual genetic values were obtained using REML/BLUP. Genetic gains were evaluated based on the Mulamba–Mock index and the developed fuzzy systems. The selection gains were similar for quantitative traits, but fuzzy logic also selected qualitative traits, and thus stands out as a potential tool for kale genetic improvement. The selection of individuals by the fuzzy methodology enables estimated selection gains in a favourable direction for qualitative and quantitative traits, enabling the automation of more accurate and standardised decision-making.

Color analysis and UV-VIS-NIR spectroscopy in the selection of Passiflora edulis hybrids for fresh consumption

2025-10-21T17:48:58+00:00

In this study, an alternative method was developed to evaluate fruit and pulp color, using the CIE-L*a*b* kernel space and near-infrared reflectance spectroscopy in predicting the chemical characteristics of Passiflora edulis fruits. Five passion fruit hybrids were evaluated, four with purple-skinned (H09-163, H09-164, H09-166, and H09-125) and one with yellow--skinned (H09-165), in addition to BGP418 (control, yellow-skinned). BGP418 stood out for most physical characters, mainly in the weight of the fruits (224.67 g) and the pulp with seeds (112.77 g). However, its pulp yield was 11% lower compared to other genotypes. Cluster analysis based on fruit skin and pulp color using CIE-L*a*b* space, revealed greater consistency of groups compared to using the conventional method with a color palette. A higher soluble solids content was recorded in fruits with light purple-skinned and light-yellow pulp. Based on the skin and pulp color, the other chemical characteristics did not differ between the groups formed. With UV-VIS-NIR spectra, it was possible to distinguish the genotypes in the 350 and 2,500 nm spectra and the separation between the purple and yellow-skinned l genotypes. However, there was no consistent grouping in relation to the skin and pulp color or relationship with the chemical characteristics of the fruits. The breeding program can utilize the information generated to continue the development of cultivars for fresh consumption.

Effects of sodium hypochlorite on seed germination and seedling emergence in Rangpur lime

2025-10-21T17:49:00+00:00

Citrus seedlings are typically propagated through grafting, using rootstocks grown from seeds. However, the coating of citrus rootstock seeds can hinder germination. Therefore, applying sodium hypochlorite (NaClO) provides an alternative to manually removing the seed coat, potentially enhancing seed germination and seedling emergence. This study investigates the use of sodium hypochlorite (NaClO) as a scarification agent on freshly harvested Rangpur lime seeds to improve germination and seedling emergence. The experiment employed a completely randomized design with a 3 × 3 factorial arrangement and an additional treatment across four replications. The variables assessed included three NaClO concentrations (0.0% - distilled water; 2.5%, and 5.0% active chlorine) and three soaking durations (3, 6, and 9 hours), with a control of unsoaked seeds retaining their coats. The evaluated parameters were germination rate, first germination count, seedling emergence, speed index, and mean seedling emergence time. Results showed that NaClO effectively degrades the seed coat, with a 2.5% concentration for 6 hours optimizing germination. While NaClO treatment did not alter emergence rates, it reduced the average time to seedling emergence. Conversely, a 5.0% concentration for 9 hours detrimentally affected germination and vigor. Sodium hypochlorite soaking presents a viable alternative for seed coat removal, accelerating germination and emergence processes in Rangpur lime tree seeds, potentially enhancing seedling production efficiency.

Bradyrhizobium japonicum doses and fertilizer from cupuaçu residues: seedling quality, chlorophyll content, and photosynthetic efficiency in Mezilaurus itauba

2025-10-21T17:49:03+00:00

This study evaluates the optimal dose for maximum technical efficiency of Bradyrhizobium japonicum (B. japonicum), both with and without a fertilizer derived from cupuaçu residues (FERCup), on the early growth, seedling quality, and physiological metrics of Mezilaurus itauba in the northern Amazon. We assessed several parameters: shoot height (SH, cm), stem diameter (SD, mm), shoot dry mass (SDM, g plant^-1), root dry mass (RDM, g plant^-1), total dry mass (TDM, g plant^-1), Dickson Quality Index (DQI), chlorophyll a (CHL a, μg mL^-1), chlorophyll b (CHL b, μg mL^-1), total chlorophyll (CHL total, μg mL^-1), Nitrogen Balance Index (NBI), specific leaf area (SLA, cm² g^-1), and leaf area ratio (LAR, m² g^-1). A B. japonicum dose of 0.30 mL L^-1, with or without FERCup, enhanced seedling quality and robustness in M. itauba under the study conditions. Including FERCup at these doses significantly improved the morphological traits of the M. itauba seedlings. Additionally, B. japonicum doses of 0.2 and 0.4 mL L^-1 with FERCup positively impacted all physiological indices in M. itauba seedlings 180 days post-transplant.

Inference of leaf nitrogen concentration using machine learning on data resampled to the spectral resolution of Sentinel-2

2025-10-21T17:49:06+00:00

Nitrogen (N) is among the main nutrients widely used in agriculture worldwide; however, its administration and management can be challenging. Excess nitrogen is harmful to plant health and the environment, requiring effective monitoring of leaf nitrogen concentration (LNC) in field crops. Remote sensing stands out as a valuable tool in this context. This study contributed to the monitoring of LNC by implementing a machine learning algorithm based on the processing of reflectance data from Sentinel-2 (S2) satellites obtained via spectral resampling. For this purpose, five independent datasets containing leaf reflectance measurements collected by spectroradiometers were resampled to the spectral resolution of the sensors onboard the S2 satellites. LNC prediction models were developed from the resampled datasets, using Support Vector Regression (SVR) and Random Forest Regression (RFR), with 75% of the data from each set used to train a model and the remaining 25% for validation. The models demonstrated good predictive power, with the Root Mean Squared Error (RMSE) ranging from 0.39 to 0.94%. Furthermore, this study investigated the transferability of the models' predictive power by using 100% of the data from each set for training and validating predictions on the other sets. To improve transferability, the Transfer Component Analysis (TCA) technique was applied to adapt domains between the sets. This analysis revealed favorable results, especially with the TCA-SVR and TCA-RFR combinations, highlighting a greater capacity to extract transferable spectral features between different leaf reflectance datasets. It was concluded that spectral resampling does not hinder the development of effective LNC prediction models. Aligning this resampling with the resolution of Sentinel-2 sensors, resulted in more efficient monitoring of LNC, eliminating the need to individually reference each sampling point. This approach simplified the monitoring process, reduced both time and costs, and was directly beneficial to producers.

Non-destructive method for predicting the area and weight of red pitaya cladodes using linear dimensions

2025-10-21T17:49:10+00:00

The leaf area estimation of crops is a critical analysis because it indicates the photosynthetically active area of the plant. However, some methods are more expensive and difficult to apply to crops, such as pitaya. Thus, the objective of the present work was to determine a non-destructive method of estimating the area and weight of pitaya cladodes using linear dimensions. In an experimental orchard, 101 pitaya cladodes of the species Selenicereus undatus were collected, and the length (L), width (W), cladode area (CA), fresh mass (FM) and dry mass (DM) of the cladodes were measured. The product between the cladodes’ length and width (LW) was then calculated. Linear, non-intercept linear and power models were used to predict the area and weight of cladodes using allometric equations. The criteria for choosing the best equations were based on Pearson’s coefficients of determination and correlation, Willmott’s agreement index, Akaike’s information criterion, root mean squared error and mean absolute error. The equations constructed with the power and linear model were the most suitable for predicting cladode area (CA = 5.577 * LW^0.541), cladode fresh mass (FM = 8.50 * W^1.138) and cladode dry mass (MD = 3.03 + 1.74 * W). Thus, it was possible to construct a non-destructive and reliable method for predicting the area and weight of pitaya cladodes using the linear dimensions of the cladodes (length and width).

Sewage sludge in the production of chrysanthemum (Dendranthema grandiflora) and petunia (petunia x hybrida) seedlings

2025-10-21T17:49:11+00:00

Sewage sludge generated from wastewater treatment plants is an environmental and economic liability that burdens not only waste management companies, but the society at large, because it causes environmental damage. Therefore, this study aimed to seek an alternative to the destination of this sludge, such as using it as a substrate to produce chrysanthemum (Dendranthema grandiflora) and petúnia (petunia x hybrid) seedlings. The sludge was collected at CASAN, Florianópolis (SC-Brazil), and subjected to solar drying for later application in proportions of 0, 5, 10, and 25%, together with soil collected from the Ressacada Farm Experimental Station, and used as inoculum for arbuscular mycorrhizal fungi. The parameters used in the analyses were plant height (cm), root length (cm), production of aerial part dry matter, production of root dry matter (g), nitrogen content in the aerial part (g kg^-1), nitrogen accumulation in the aerial part (mg plant^-1), phosphorus content in the aerial part (g kg^-1), phosphorus accumulation in the aerial part (mg plant ^-1), soil arbuscular mycorrhizal fungi spore count (in 50 cm of soil), mycorrhizal colonization (%), and pH of the substrate (pre- and post-treatment). The study showed that solar drying is an efficient method of eliminating pathogens, and the sludge was classified as proper for agricultural application. The results showed that the best dosages of sludge for the growth of chrysanthemum and petunia varied from 5 to 13%, and 13 to 18%, respectively. These concentrations provided the best yield for all variables tested, except mycorrhizal colonization and spore counting that decreased as the sludge concentration increased.

Defoliation management and boron application as a strategy to reduce poor fruit set and improve the quality of ‘Merlot’ grapes

2025-10-21T17:49:13+00:00

‘Merlot’ grapevines hold significant importance in Brazilian viticulture, particularly within the high-altitude region of Santa Catarina. However, they often experience a physiological disorder known as poor fruit set and shot berries, which results in clusters with few berries, uneven ripening, and reduced productivity. Therefore, this study evaluated the effectiveness of different defoliation and boron application strategies in mitigating poor fruit set. The evaluated treatments included: i) 3 defoliations with boron application at phenological stages 17 (developed inflorescence), 23 (full flowering), and 35 (beginning of maturation); ii) 3 defoliations without boron application at the same phenological stages; iii) 1 defoliation treatment with boron application at full flowering; iv) 1 defoliation treatment with boron application at the beginning of maturation; and v) a control with no defoliation but with boron application. Berry drop evaluations were conducted during the 2023 and 2024 harvests. Our findings showed that performing 3 defoliations at the developed inflorescence, full flowering, and the beginning of maturation stages did not reduce poor fruit set in ‘Merlot’ grapes cultivated in the Serra Catarinense region. However, these treatments were associated with increased total polyphenol and anthocyanin contents, improved color parameters, and enhanced color intensity in the wine. Late defoliation treatments decreased color intensity and anthocyanin and total polyphenol contents in ‘Merlot’ wines.

Dry matter and minerals in the aerial part of the banana tree ‘BRS SCS Belluna’

2025-10-21T17:49:16+00:00

Brazil is a large banana producer, and technological advances have resulted in gains in national productivity. Developing new cultivars is part of the technological package that ensures the success of this activity. Among these cultivars, the ‘BRS SCS Belluna’ banana tree launched in 2016 through a partnership between Embrapa and Epagri, presents important agronomic characteristics for the sector and appears to be an option for market diversification with its small, sweet fruit. Banana trees are plants with high rates of phytomass production, which is regulated by the mineral distribution between their organs and influences mineral cycling and export. Thus, the objective of this study was to evaluate the phytomass and minerals in the aerial part of the BRS SCS Belluna banana tree. Two production cycles were evaluated. The organs and tissues of the aerial part were separated into the pseudostem, inflorescence, stalk, leaves, peel, and pulp. The pulp had the highest dry matter content, and the pseudostem had the highest accumulation, resulting in an average cycling of 64% of the produced dry matter. Potassium and manganese were the most accumulated macro- and micronutrients in the organs and tissues evaluated, except for the leaves, where nitrogen and calcium were predominant. In general, the inflorescences and leaves had the highest mineral concentrations, whereas the pseudostem had the highest exports. The highest cycling rates were observed for calcium and magnesium (macronutrients) and manganese (micronutrient). The highest removal rates were observed for nitrogen and phosphorus (macronutrients) and boron (micronutrient).

Performance of pineapple cultivars inoculated with Fusarium guttiforme isolates on different substrates

2025-10-21T17:49:20+00:00

Fusariosis in pineapples causes significant losses to producers. Knowing practices that reduce disease severity is important, as cultivation in Brazil mainly relies on the susceptible cultivar ‘Pérola’. Therefore, this study aimed to analyse the vegetative development and severity of fusariosis in different pineapple cultivars inoculated with Fusarium guttiforme isolates in various substrates. Isolates were collected and inoculated into ‘Pérola’ and ‘BRS Imperial’ cultivars planted in different substrates. Vegetative characteristics and disease severity were assessed. Evaluations were carried out fortnightly over 120 days. A randomised block design was used in a triple factorial arrangement 5 x 2 x 3 (five isolates x two cultivars x three substrates). Data were analysed using Sisvar software. The cultivars showed distinct vegetative development, with ‘Pérola’ being susceptible to all isolates, displaying reduced plant height, leaf D length and width, and number of active leaves. The pineapple leaf D is used to measure plant growth and nutritional status. Isolates 3 and 7 led to the death of several ‘Pérola’ plants. The substrate that favoured the highest disease severity was composed of sand and soil in a 3:1 ratio. The ‘‘BRS Imperial’’ cultivar showed resistance to all isolates and substrates. Finally, pineapple cultivation will develop better in substrates with favourable physico-chemical compositions and proper fertilisation. The ‘BRS Imperial’ cultivar is viable for producers as it is resistant to fusariosis and can withstand abiotic stress conditions.

Nitrogen fertilization, fungicide application, and genetic resistance for the management of diseases on wheat

2025-10-21T17:49:21+00:00

Nitrogen (N) fertilization is a common practice to increase grain yield worldwide. This study aimed to determine the effects of three N rates (70, 130, and 200 kg ha⁻¹, referred to as low, recommended, and high, respectively) and a pre-mix fungicide (bixafen + prothioconazole + trifloxystrobin) on the disease intensity and grain yield of 2 early-maturing wheat cultivars named as TBIO Audaz and TBIO Tibagi. Two field experiments were conducted during the 2019 and 2020 growing seasons using the split–split plot design. Tan spot, powdery mildew, leaf rust, and Fusarium head blight (FHB) were the primary diseases observed. The recommended and high N rates reduced the area under the disease progress curve (AUDPC) for tan spot. However, the AUDPC for powdery mildew increased with high N for both cultivars, but N rates did not affect leaf rust or FHB. The use of early maturing wheat cultivars did not prevent the occurrence of FHB damage, except on plants from cultivar TBIO Audaz known to be moderately resistant. When combined with N fertilization, fungicide application reduced the AUDPC for tan spot, powdery mildew, leaf rust, and FHB by 31, 33, 75, and 40%, respectively, compared to the non-treated control. The cultivar × fungicide and cultivar × N interactions were significant (p < 0.05) for AUDPCs and yield variables. Both the recommended and high N rates similarly increased the yield, health area duration, and tan spot control at the same level compared to the low N rate. These findings combined with economic and cost-efficiency analyses suggest that using a moderately resistant cultivar with recommended N rates help to maintain adequate N use efficiency and economic returns to growers.

Physical properties of Ferralsols in response to sugarcane cultivation in the state of Goiás, Brazil

2025-10-21T17:49:24+00:00

For sugarcane production, soil physical properties are essential indicators of crop growth, development and sustainable productivity. This study evaluated the physical properties of different textural classes of Latossolos Vermelhos distróficos (Ferralsols) under sugarcane cultivation, with and without vinasse application. The study was conducted under the soil, climate and management conditions of the counties of Quirinópolis and Goianésia, both in Goiás State, Brazil. In Quirinópolis, variety RB 867515 was planted and evaluated over 1, 3, and 7 consecutive sugarcane cycles. In Goianésia, cv. CTC4 was cultivated and assessed in 1, 2, and 4 cycles. At both locations, a plot with native vegetation was used as reference. To evaluate bulk density, macroporosity, microporosity, total porosity, macro- to micropore ratio, soil aeration capacity and relative bulk density, soil samples were collected from the 0.0-0.10, 0.10-0.20, 0.20-0.30, and 0.40-0.50 m layers. It was found that soil physical properties were affected by the crop cycles, and in Quirinópolis, the plots in the first and third cycles were most affected by increased bulk density. In Goianésia, the physical properties were negatively affected in the first and second sugarcane cycles. Regardless of the soil texture and vinasse application, the soil physical properties were negatively affected by the implementation or renewal of sugarcane plantations up to the third consecutive sugarcane cycle, but improved from the fourth to the seventh cycle without sugarcane renewal.