Abstract in English:

ABSTRACT. Nitrogen top dressing is essential to supplement maize needs in crop fields. In Brazilian agriculture, a spreader is the most popular equipment used to apply nitrogen fertilizer to growing maize. However, spreaders present at least three problems: non-uniform fertilizer placement, granular fertilizer placement on the top of maize leaves, and granular fertilizer scattering without a precise target. As an alternative, liquid nitrogen fertilizer applied in side bands of maize rows can improve nutrient placement and dosage precision. The objective was to design a liquid fertilizer application device for assembly on a boom sprayer. For this, a programming model was simulated in Matlab. The liquid fertilizer source, fertilizer rate, maize row width, and boom sprayer speed were considered as input parameters. The simulation assisted in the design of the liquid fertilizer device. The device was constructed and evaluated on a laboratory bench. As a result, pressure, nozzle outlet flow, and forward speed were compatible with a self-propelled sprayer. The proposed process showed the potential to improve the outlet flow quality (coefficient of variation less than 10%). In addition, the liquid fertilizer device was considered simple to assemble in the sprayer’s boom. These characteristics could represent some attractive aspects for the farmers.

Abstract in English:

ABSTRACT. Various techniques have been employed to assess the stability and adaptability of crops, where mixed models or BLUP-based indexes like WAASB proving particularly more benefit. We introduce rYWAASB, an open-source R package designed to offer a novel index for quantifying both stability and performance of a biological trait. It quantifies the stability and performance of individuals/genotypes e.g. in plant breeding programs. It simultaneously considers the trait of interest, along with the WAASB index in a new perspective. The package then provides bar plots, PCA diagrams, and optimum cluster number estimate and cluster categorization by MCMC algorithms. For executing the package, a field experiment was conducted on chickpea (Cicer arietinum L.) from 2018 to 2020, evaluating the grain yield and days to maturity in rainfed conditions. The genotypes have put in 7 clusters for grain yield while genotypes 18, 69, and 5 were the most stable, exhibiting the highest grain yields, but genotypes 2, 103, 27, and 88 are identified as the earliest ripening varieties, exhibiting a higher degree of stability. The findings highlighted the effectiveness of the novel rYWAASB index in distinguishing observations in the experiment, suggesting its potential application in agronomic and plant breeding stability and adaptability programs.

Abstract in English:

ABSTRACT. Height-diameter models are widely used to estimate tree height from diameter at breast height (DBH) and play a crucial role in forest inventories by reducing fieldwork effort. However, statistical challenges such as nonlinearity, heteroscedasticity, nonnormality, and outliers can compromise model accuracy. To address these issues, this study proposes a generalization of Scolforo’s height‒diameter model (Scolforo, 1998), which incorporates random effects to improve flexibility and fit. With observational data from Eucalyptus urograndis plantations, we present a step-by-step framework for model fitting, inference, and validation. Our approach considers hierarchical structures and variability across stands to improve predictive performance. To rigorously assess model adequacy, we conducted a simulation study under various scenarios, evaluating goodness-of-fit with deviance, randomized quantile residuals, and least-confounded residuals. These diagnostics identify misspecification and enable robust parameter estimation. Additionally, we provide a detailed tutorial (Appendix B) for implementing the model in R that encompasses (i) inference for fixed and random effects, (ii) local influence analysis to detect sensitive observations, and (iii) residual-based diagnostics adapted to mixed models. Our results reveal the adaptability of the model to complex data structures while maintaining interpretability. The proposed framework provides forest researchers a reliable tool for height prediction that combines theoretical rigor and practical applicability. The accompanying R tutorial increases reproducibility and facilitates the integration of the framework into forest inventory workflows.

Abstract in English:

ABSTRACT. This study analyzes the susceptibility of Diaphorina citri, a pest of great relevance to citrus farming, to different concentrations of the entomopathogenic fungi Cordyceps fumosorosea and Beauveria bassiana, which are widely used in biological control. The data were evaluated by means of binomial regression(η = β₀ + β₁log(dose), the linear predictor) with a Bayesian approach, considering different link functions: Basic (logit, probit, cauchit, cloglog, and loglog), power, and reverse power. Model selection was based on the lowest deviance information criterion (DIC) value. For both fungi, the selected models showed a good fit, as indicated by the simulated envelopes of the normalized quantile residuals. For C. fumosorosea, the model with the cauchit link function presented the best fit (DIC = 53.41), with β̂₀ = -11.95 [-19.19;-7.16] and β̂ 1 = 2.37 [1.44; 3.81], and a 90% lethal dose (LD 90) of 6.38 log(conidia mL-1) [5.83; 7.17]. For B. bassiana, the reverse power cloglog function showed the best performance (DIC = 62.17), with β̂ 0 = -3.75 [-7.85;-1.90] and β̂ 1 = 0.88 [0.21; 2.10], and an LD 90 of 10.69 log(conidia mL-1) [8.81; 13.73]. In both models, the regression parameters were statistically significant, while the flexibility parameter (λ) did not show sufficient evidence to justify the use of extended functions. In addition, C. fumosorosea was, in general, more effective than B. bassiana, except in the lower portion of the experimental dose range (4.00 to 4.52 log(conidia mL⁻¹)), in which the latter fungus showed slight superiority. The analysis highlights the importance of a careful choice of the link function in the modeling of binary bioassays, especially regarding decisions on the application of bioinsecticides in agricultural contexts.

Abstract in English:

ABSTRACT. 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 (Qst) 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.

Abstract in English:

ABSTRACT. 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.

Abstract in English:

ABSTRACT. Knowledge of soil hydraulic conductivity is indispensable due to its application in studies of soil water dynamics, water balance, and irrigation management in crops that directly affect water and soil conservation. The objective of this study was to propose two alternatives for determining unsaturated hydraulic conductivity using existing methodologies in the literature based on the variation in soil moisture and water storage monitored using a moisture sensor in a drainage lysimeter and under field conditions. Two experiments were conducted, one in a drainage lysimeter and the other in the field at Embrapa Cassava and Fruit Farming, Cruz das Almas, Bahia State, Brazil. A comparison of moisture and storage variation between the proposed methodologies was carried out based on statistical coefficients. The methods based on moisture and storage variation in a layer estimated the unsaturated hydraulic conductivity with good accuracy compared to Hillel’s method. Hydraulic conductivity showed greater variation in the initial phase of water redistribution in the soil, either in the lysimeter test or in the field application after irrigation. The proposed methods based on moisture and storage variation can be applied to studies on soil water dynamics in the soil moisture profile using soil water sensors.

Abstract in English:

ABSTRACT. The Agricultural Production Systems Simulator (APSIM) has been widely used in studies to simulate the growth and development of pastures and grain crops in single-crop and intercropping cultivation systems. The objective of this study was to parameterize the APSIM and evaluate its effectiveness in estimating the growth and productivity of maize and signalgrass (Urochloa ruziziensis) in single-crop and intercropping systems in northern Piauí State, Brazil. Data were collected from the experimental field of the Brazilian Agricultural Research Corporation (Embrapa Mid-North) in Teresina, Piauí State, Brazil. The photosynthetically active radiation and soil water content were the main measurement parameters to calibrate the light extinction coefficient and radiation use efficiency, with adjustments to the phenological and structural parameters of maize. The leaf, stalk, and total shoot dry weights and leaf area index (LAI) of both crops and maize organs (husk, cob, and grains) were evaluated. The model showed coefficient of determination (R2) values ranging from 0.81 to 0.99 and Nash-Sutcliffe efficiency (NSE) values ranging from 0.72 to 0.99 for single-crop cultivation of signalgrass; R2 values ranging from 0.87 to 0.93 and NSE values ranging from 0.62 to 0.67 for intercropping cultivation of signalgrass; R2 values ranging from 0.43 to 0.97 and NSE values ranging from -3.33 to 0.95 for single-crop cultivation of maize; and R2 values ranging from 0.30 to 0.93 and NSE values ranging from 0.21 to 0.92 for intercropping cultivation of maize. The APSIM model provided an adequate fit for growth simulations of signalgrass and maize in single-crop and intercropping systems. It can simulate the growth and yield of irrigated signalgrass and maize in single-crop and intercropping systems.

Abstract in English:

ABSTRACT. 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.

Abstract in English:

ABSTRACT. The aim of this study was to select and characterize epiphytic bacteria associated with native plants of the Caatinga biome with the potential to control multiple phytopathogenic fungi of agricultural importance. Bacterial isolation was performed from the phyllosphere of endemic species of the Cactaceae and Bromeliaceae families. Colonies with distinct morphologies were purified and preserved for further testing. Antagonistic activity was evaluated via three approaches, namely, direct confrontation, the production of volatile organic compounds (VOCs), and the addition of cell-free supernatant, to test their potential against Colletotrichum truncatum, Corynespora cassiicola, Sclerotinia sclerotiorum, Fusarium solani, and F. graminearum. All assays were conducted in a completely randomized design (CRD). The most promising isolates were identified via 16S rRNA gene sequencing and were classified into the genera Burkholderia, Acinetobacter, and Bacillus, with a predominance of Bacillus. The seven isolates selected showed direct inhibition rates against the pathogens ranging from 57.14 to 92.86%. For the production of VOCs, the most efficient isolates were Acinetobacter sp. EQP5 and Bacillus sp. UMB3, with percentages of inhibition of 80.20 and 91.52% against C. truncatum and F. solani, respectively. However, the cell-free supernatant had no significant inhibitory effect on the tested fungi. The results show that epiphytic bacteria isolated from plants native to the Caatinga use different mechanisms of antagonism and have the potential to be used as biocontrol agents in the management of agricultural diseases.

Abstract in English:

ABSTRACT. Huanglongbing (HLB), one of the most destructive citrus diseases worldwide, is caused by a phloem-limited bacterium for which there are no effective control measures. Its rapid spread poses a major threat to citrus production globally. In Brazil, legislation requires citrus growers to submit semi-annual reports on HLB-infected plants; however, data inconsistencies have been observed. This study analysed official reports from 2015 to 2018 in northwestern Paraná State, Brazil, revealing fluctuating disease incidence, with the highest levels recorded in 2015. Contributing factors include inaccurate data reporting and growers’ reluctance to eradicate infected plants. Field inspections in Nova Esperança (Paraná State) showed that HLB incidence ranged from 4.79 to 55.08% among orchards and was strongly influenced by orchard size and management practices. Well-managed orchards exhibited lower infection rates, whereas those retaining infected trees showed greater disease spread. PCR of asymptomatic plants detected no bacterial presence in large, well-managed orchards, and smaller, poorly managed orchards exhibited high infection rates. These findings emphasise the critical role of consistent disease and vector management in mitigating HLB dissemination.

Abstract in English:

ABSTRACT. 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.

Abstract in English:

ABSTRACT. 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.

Abstract in English:

ABSTRACT. This study aimed to correlate the developmental stages of the embryo sac with the morphometric traits of spikelets and to characterize the expression of the BbrizRan, BbrizSti1, and BbrizAGL6 genes in Urochloa ruziziensis (sexual) and U. decumbens (apomictic). Data on the length and diameter of spikelets and anatomical sections were also obtained. Gene expression was determined using RT-qPCR in spikelets at megasporogenesis and megagametogenesis. The spikelet length could be used as a reliable morphological marker to discriminate between the two stages in both species. The embryo sacs observed were of the Polygonum type in U. ruziziensis and the Panicum type in U. decumbens. RT-qPCR analysis revealed that the BbrizRan, BbrizSti1, and BbrizAGL6 genes were differentially expressed in the studied species during reproductive development. The BbrizSti1 gene was more highly expressed in U. decumbens (apomictic) than in U. ruziziensis (sexual) during megasporogenesis, while for BbrizRan, U. decumbens showed higher expression than U. ruziziensis during both megasporogenesis and megagametogenesis. An increase in the expression level of BbrizAGL6 was observed in both species at both developmental stages of the embryo sac.

Abstract in English:

ABSTRACT. Pitaya species can be self-compatible, partially self-compatible, or self-incompatible. Information related to floral biology and pollination is important for identifying the causes of self-incompatibility and the factors that limit self-pollination among pitaya species. This research was carried out to evaluate floral morphology, pollen viability, stigma receptivity, and different pollination methods in genotypes of Selenicereus undatus and S. monacanthus. During the flowering period, the flower buds were selected, identified, and protected in the pre-anthesis stage to evaluate floral morphology, pollen viability, and pollen transfer methods at the time of anthesis. The genotypes had complete flowers and showed differences in floral morphology related to the quantity and coloration of the protective tissues of the flower buds. Herkogamy was more pronounced in S. monacanthus. Anthesis in both species was coincident, with a longer duration in S. undatus. During anthesis, both species presented receptive stigmas and viable pollen grains, with dehiscent anthers before the flowers opened. The S. monacanthus genotype was self-incompatible. Seeds from self-pollination showed lower germination. Manual cross-pollination between the genotypes promoted a high fruit set and the formation of fruit of a high commercial standard.

Abstract in English:

ABSTRACT. Popcorn is a distinct type of maize with a high market demand. In Brazil, there is a shortage of national cultivars that meet production and marketing needs, so seeds are imported, hindering the growth of this sector. Nevertheless, its cultivation is important and can be enhanced with investments in genetic improvement aimed at optimizing characteristics such as productivity. Molecular markers support this type of research: They allow the genetic characterization of lines and inferences about genetic variability. Microsatellites such as simple-sequence repeats (SSRs) are widely used in genetic studies due to their high reproducibility and polymorphism. SSR-expressed sequence tag (EST) markers are microsatellites related to transcribed sequences. Functional variability is linked to the maximization of genetic gains, making the study of these regions valuable. In this context, the present study used SSR-EST markers to characterize the productivity of 47 popcorn lines from the UENF Germplasm Bank, selected for their high performance in previous studies. Young leaves of the lines were collected for DNA extraction, which was used for polymerase chain reaction (PCR) with 30 preselected primers. The amplified material was subjected to capillary electrophoresis for identification and separation of alleles. The data were converted into a dissimilarity matrix, which allowed for the estimation of diversity metrics such as the number of alleles, the polymorphic information content, observed heterozygosity, expected heterozygosity, and the inbreeding coefficient. A total of 94 distinct alleles were detected, with an average of 3.13 alleles per locus, indicating that, although the lines present high levels of allelic fixation and inbreeding, they retain moderate genetic variability for population configuration. A dendrogram created using unweighted pair group method using arithmetic mean revealed an optimal number of six populations. This information provides indications of specific genotypes for crosses that can maximize heterosis in hybridizations to support the improvement program.

Abstract in English:

ABSTRACT. With the increasing demand for more productive cultivars that are tolerant or resistant to diseases and pests, the exploration of genetic resources combined with molecular analyses has proven to be an essential research strategy. Through molecular analysis, it is possible to identify and select desirable traits with high precision, increasing the efficiency of breeding programs. This study aimed to analyze the population structure and genetic diversity of traditional sweet cassava accessions collected from rural and peri-urban areas of municipalities in the states of Mato Grosso, Paraná, Santa Catarina, and São Paulo States, Brazil, via microsatellite markers. A total of 227 traditional sweet cassava accessions were evaluated using 29 microsatellite markers. The analysis revealed polymorphisms across all loci, with an average of 3.21 alleles per locus and 12 rare alleles identified within the population, potentially linked to unique genetic traits. The mean polymorphism information content (PIC) value of 0.52 suggests that the markers were moderately to highly informative. The average observed heterozygosity (Ho) was 0.65, whereas the average genetic diversity was 0.60. The sweet cassava accessions were grouped into four subpopulations on the basis of population structure at K = 4. The PhiPT value was 0.13, indicating low to moderate genetic differentiation among the evaluated subpopulations and highlighting their distinct genetic characteristics. The most divergent combinations were observed between the accessions from Western Paraná and Northern Mato Grosso, as well as between accessions from Northern Mato Grosso and Central-Western Santa Catarina. These results are important for addressing aspects related to germplasm conservation and the demands of genetic improvement programs, which benefit from high genetic variability, for the development of new sweet cassava cultivars.

Abstract in English:

ABSTRACT. The use of nitrogen fertilizers in maize crops must be reduced, and a potential alternative is the use of diazotrophic bacteria of the genus Azospirillum. This research aims to characterize the efficiency of the association with Azospirillum brasilense (Az) among maize genotypes on grain yield. Forty-eight experimental single-cross maize hybrids obtained from the cross in a partial diallel scheme between eight and six inbred lines were used. The maize hybrids were evaluated in seven environments, considering the grain yield (GY) without nitrogen (N) topdressing and without Az inoculation, GY with N topdressing and without Az inoculation, GY without N topdressing but with Az inoculation, and the efficiency to Az. The hybrids’ GY varied in the presence of Az, indicating a differential response to the bacteria and confirming that this association enables the selection of more efficient genotypes since some hybrids maintained similar yield levels when N topdressing was replaced by Az inoculation. Low or medium correlation estimates were obtained among the considered traits, indicating a low correspondence between yields under the different conditions and between yields and the efficiency of the association with Az, suggesting that indirect selection for these traits is not efficient. These results indicate that it is possible to select the most efficient maize genotypes.

Abstract in English:

ABSTRACT. One of the most notorious pathogens affecting tobacco production is tobacco bacterial wilt (TBW), caused by Ralstonia solanacearum. Controlling TBW is a global issue, and developing more resistant cultivars is one of the solutions. Therefore, this study investigated the effectiveness of recurrent selection (RS) as a breeding strategy to enhance resistance to R. solanacearum in tobacco. We also aimed to identify the appropriate progeny type for RS. The trials were carried out in an area where the pathogen is known to occur, with seedlings inoculated with R. solanacearum to assure the presence of the pathogen. The incidence of the pathogen was evaluated over two seasons. In the first year, we utilized 100 S1:2 progeny from the original population (cycle 0) and 108 half-sib progeny of cycle I. In the subsequent year, we evaluated 196 S0:1 progeny of CI and 176 half-sib progeny of cycle II. Additionally, to ensure the presence of the pathogen, we inoculated R. solanacearum 40-45 days after transplanting the seedlings. The incidence of the pathogen was assessed based on the number of plants showing symptoms (%). Although the difference between cycle 0 and cycle II was relatively small, the results suggest that recurrent selection was successful in accumulating resistance alleles, as reflected in the positive association between disease resistance and agronomic traits.

Abstract in English:

ABSTRACT. Citrullus lanatus (mini-watermelon type) ‘Sugar Baby’ seeds were irradiated with Cobalt-60 gamma rays at doses of 0 (control), 100, 200, 300, and 400 Gy to enhance genetic variability. Germination, anomalies, development, flowering, and fruiting were assessed through 29 quantitative and qualitative traits and 79 molecular markers (random amplified polymorphic DNA (RAPD), intersimple sequence repeat (ISSR), and simple sequence repeat (SSR)). Gamma radiation significantly influenced germination (p < 0.001), with low doses showing neutral or positive effects and higher doses reducing germination. The 50% lethal dose (LD50) was determined as 325.81 Gy. Of 25 evaluated traits, most showed highly significant differences (p < 0.001), with developmental improvements at 100 and 200 Gy and deleterious effects at 300 and 400 Gy. Phenotypic diversity increased with the dose, forming distinct clusters: three at 400 Gy, five at 300 Gy, and fewer at lower doses. Molecular analyses revealed changes induced by two RAPD markers, five ISSR markers, and one SSR marker. Seventeen morphotypes that differed from the control were identified. These results confirm the efficiency of gamma radiation in inducing significant phenotypic and genetic variability, enabling LD50 determination and the detection of previously unreported molecular alterations in mini watermelon.

Abstract in English:

ABSTRACT. The purpose of this study is to analyze the genetic and residual variability of the grain yield trait in Coffea canephora using the Bayesian multi-trait model. Thirty-six varieties of conilon coffee were used. The design was randomized blocks, with three replications, nine plants per plot. Data was analyzed using multi-trait Bayesian models with an arbitrary number of random effects, employing a Gibbs sampler. The covariance matrix of the random effects is assigned as a prior Inverse Wishart distribution. A total of 1,800,000 samples were generated, with a burn-in of 5,000 and a thin of 5 interactions, resulting in 1,795,000 samples. The broad-sense heritability, residual and genetic variations were calculated from the posterior distribution. The variance-covariance matrix for the genetic factor shows significant variability among the traits. The 95% credibility intervals for the variances and covariances are narrow, indicating accurate estimates. The data is adequate to provide reliable estimates, indicating significant genetic effects on most traits. The residual variance-covariance matrix reveals heteroscedasticity among the traits. According to the results, accurate estimates of broad-sense heritability obtained by the Bayesian methods can guide breeding programs, in addition to identifying traits with high genetic variability and potential for response to selection. The Bayesian approach provided robust and detailed estimates, aligning with previous studies and offering valuable insights for breeding programs.

Abstract in English:

ABSTRACT. The purpose of this study was to evaluate the efficiency of using fuzzy controllers as auxiliary tools for different adaptability and stability methods aiming at the selection of conilon coffee clones. Thirty-six conilon coffee clones were evaluated for grain yield (bag ha-1), within seven harvests (2018 to 2024). Adaptability and stability were evaluated using the hybrid fuzzy controller (Eberhart & Russell, 1966; Cruz et al., 1989; Annicchiarico, 1992). There was significance for the effects of crops, clones, and clone by crop interaction. The Eberhart & Russell method classified clones 3, 16, 24, and 33 as having general adaptability, and 32 and 36 as having adaptability to unfavorable environments. In the Annicchiarico method (1992), clones 4, 10, 24, and 26 were classified as general behavior. Clones 2 and 8 show high adaptability to adverse environments, while clones 10, 23, and 29 excel in favorable conditions. By Cruz et al. (1989), clones 28 and 31 did not correspond to any classification through this controller. In this methodology, clone 29 presented the highest stability index. The use of these methodologies is a viable alternative for the classification of clones. The differentiated behavior of clones is influenced by environmental conditions, which justifies the use of different adaptability and stability methodologies. The use of fuzzy controllers in the recommendation of conilon coffee clones is a useful and promising tool in plant breeding programs. Clones 2 and 8 showed high adaptability to adverse environments, while clones 10, 23, and 29 excelled in favorable conditions.

Abstract in English:

ABSTRACT. Tomatoes are an important economic crop, a key component of the human diet, and an important source of vitamins, minerals, and carotenoids. Tomato productivity is dependent on many abiotic and biotic factors, and soil microbiota plays important roles in nutrition, growth, and immunity. In this study, we used high-throughput 16S and ITS sequencing to assess the bulk soil and rhizosphere microbial community composition at two geographically distinct sites, each with two separate greenhouses with low and high tomato weights. As a result, the bacterial diversity in the soil community was greater than that of the fungal community. Proteobacteria, Actinobacteria, Acidobacteria, and Ascomycota were the most abundant phyla. Although the sites presented similar rootstocks (Guardião), pedology classifications (Oxisols), and cultivation systems, the bulk soil and rhizosphere differed in terms of microbiota abundance. The rhizosphere microbiota was strongly influenced by the bulk soil. In a comparison of the tomato microbiota from the two high-tomato-weight greenhouses, the genera Bradyrhizobium and Mesorhizobium camelthorni (Proteobacteria), Bacillus (Firmicutes), and Mycochlamys (Ascomycota) were enriched, whereas the relative abundance of pathogenic fungi (Fusarium and Penicillium) decreased. Although the effective interactions between dominant bacterial and fungal groups must be investigated, we highlight the importance of metagenomic studies in discovering the crop-associated microbiota related to plant production.

Abstract in English:

ABSTRACT. 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.

Abstract in English:

ABSTRACT. 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.

Abstract in English:

ABSTRACT. 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.

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ABSTRACT. 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 * LW0.541), cladode fresh mass (FM = 8.50 * W1.138) 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).

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ABSTRACT. 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.

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ABSTRACT. ‘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.

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ABSTRACT. 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).

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ABSTRACT. 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.

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ABSTRACT. 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.

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ABSTRACT. Rice is a staple food for more than half of the world’s population. In Brazil, upland rice cultivation in the southeastern region faces competition from soybean due to its higher profitability in recent years. In this context, developing more competitive rice lines and expanding the sowing window, such as incorporating rice into the second season, can enhance its integration into cropping systems. This study aimed to evaluate the performance of elite upland rice lines under different sowing dates during the second crop season. Field experiments were conducted in Lavras, Minas Gerais State, Brazil, across 4 sowing dates in 7-day intervals, starting on January 28, 2022. Eight genotypes were evaluated in a randomized block design with a two-way factorial scheme (8 genotypes × 4 sowing dates). The assessed traits included the number of days to flowering (NDFL), plant height (PH), tolerance to Helminthosporium oryzae, and grain yield (GY). The data were analyzed using mixed models based on the restricted maximum likelihood/best linear unbiased predictor. The results revealed significant genetic variability for NDFL and PH as well as significant sowing date effects on NDFL, PH, and GY. A sharp decline in performance was observed across sowing dates, with an increase of 24 days in NDFL, a 14% reduction in PH, and sterility rates reaching 100% at the last sowing. These findings highlight the importance of genotype selection and optimal sowing timing to sustain upland rice production during the second crop season.

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ABSTRACT. The determination of crop canopy characteristics (vegetation cover, leaf area, and leaf area index) is usually obtained through costly methods or methods that require training and time. Based on this, the aim of this work was to determine whether different methods and angles for capturing images using a smartphone camera and fisheye lenses can predict information about the soybean canopy in a practical, fast, and low-cost way. Different methods of capturing images were carried out throughout the soybean cycle using smartphones, attached fisheye lenses, manual normalized difference vegetation index (NDVI) reading equipment, and destructive plant evaluations. The captured images were analyzed in the Canopeo app to determine the green cover fraction. Pearson’s correlation and regression models were used to study the association between NDVI and leaf area index (LAI). The data were compared in the vegetative and reproductive stage segments and throughout the crop cycle to determine whether the image acquisition methods were capable of estimating the variations at each crop stage. With the exception of images captured during the soybean’s reproductive stage, all methods proved to be suitable for evaluations and comparisons using the Canopeo app. Capturing images 1 m above the canopy and video were the methods that best estimated the NDVI and LAI of soybeans.

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ABSTRACT. The storage of soybean seeds is a critical aspect of the production process, making it essential for genotypes to show tolerance during this phase to maintain seed quality. This study aimed to examine and correlate lignin content in the seed coat, enzyme activity expression, and morphoanatomical characteristics of soybean cultivars with the preservation of physiological quality and storage tolerance. Eight soybean cultivars were selected, produced, and harvested under uniform edaphoclimatic conditions. Physiological quality assessments were conducted at six storage intervals: 0, 60, 120, 180, 240, and 360 days. Evaluations included tests for germination, emergence, accelerated aging, electrical conductivity, and lignin content in the seed coat. Additionally, biochemical and enzymatic analyses of antioxidant metabolism and morphoanatomical examinations were performed using light microscopy on seeds stored for 0 and 360 days. The experiment used an 8 × 6 factorial arrangement, encompassing eight cultivars and six storage periods. For the enzymatic and morphoanatomical analyses, a 4 × 2 factorial design was employed, involving four cultivars and two storage durations. The results showed that genotype significantly influenced the tolerance of soybean seeds to extended storage periods. Seeds proving high physiological quality and storage resilience exhibited reduced hydrogen peroxide accumulation and diminished lipid peroxidation. Furthermore, morphoanatomical analyses provide a promising method for selecting genotypes with enhanced physiological quality and storage tolerance.

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ABSTRACT. Ora-pro-nóbis (Pereskia aculeata Mill.) is a protein-rich member of the Cactaceae with great potential for cultivation in regions where water can be a limiting factor. The aim of this study was to verify the tolerance of this species to water deficiency and determine how microbial biomass and soil respiration are affected under these conditions. Five treatments were tested, namely control and irrigation suspension for 7, 14, 21, and 28 consecutive days, in plants propagated by seeds and cuttings. The decrease in soil moisture and soil water potential (Ψs) after 28 days of water restriction highlighted the severe impact of a lack of water on plants, especially those propagated by cuttings, which showed greater susceptibility to water stress (leaf potential -2.84 MPa). Seedlings, although affected in terms of root development and fresh mass at 28 days (leaf potential of -1.59 MPa), showed advantages in terms of shoot fresh matter and plant diameter, suggesting that propagation by seeds and root development are crucial for water stress resistance. The microbial biomass carbon, in general did not vary among the irrigation suspensions times both in plants propagated by seeds and cuttings, reinforcing the importance of microbial adaptation to stressful conditions.

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ABSTRACT. Sugarcane is a crop of great economic importance for Brazil. However, it is affected by several fungal foliar diseases that compromise its agricultural productivity. The use of elicitor agents can induce and enhance plant resistance, in addition to reducing the need for pesticides, thus promoting sustainable production. Our hypothesis was that fertilization with silicon as a constituent element of the cell wall can create greater resistance and control of foliar fungal infections responsible for red rot and ringspot diseases and has a greater effect when combined with genetic resistance. The objective was to apply and investigate the potential of silicon Si as an inducer of systemic resistance and modulator of phenotype for the control of fungi in two sugarcane cultivars, RB867515, which is recognized for its greater productivity in the Iturama-Minas Gerais region, and the transgenic cultivar CTC9001BT, which has resistance to the sugarcane borer, by analyses of morphophysiological and micromorphometric parameters. The greatest discovery of this scientific research was the positive effect of greater systemic resistance of sugarcane with different management techniques: the application of Si sources resulted in the genetic transformation of plants, as observed in the CTC9001BT cultivar with higher doses of Si. Therefore, silicon may be an option for integrated pest and disease management. However, some significant differences observed in the biometric, anatomical and micromorphometric analyses may result from genetic differences between the cultivars studied.

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ABSTRACT. Sweet potato (Ipomoea batatas L.) is a source of vitamin A, carbohydrates, organic acids, and minerals. It is rich in bioactive compounds, making it a very healthy food. Indeed, it helps in the prevention of various diseases such as cardiovascular diseases, certain types of cancer, and in controlling the glycemic index of people with diabetes. Additionally, it provides nutrients for at-risk groups, such as children and pregnant women with deficiencies in magnesium and vitamin A. In its natural form, sweet potatoes have high water activity, making them highly perishable and reducing their shelf life. This study aimed to evaluate the influence of the drying process at different temperatures (50, 60, and 70°C) and thicknesses (1, 2, and 3 mm) on the antioxidant content and phenolic compounds of two sweet potato cultivars: BDI (Brasilândia) and BDII (not cataloged). The drying process was evaluated based on 10 mathematical models, comparing the coefficient of determination (R²), chi-square (χ²) value, and root mean squared error (RMSE). The Page model stood out for the BDI cultivar and the diffusion approximation and Page models were significant for the BDII cultivar. The total phenolic content ranged from 71.67 to 99.33 mg gallic acid equivalents 100 g-1. The 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) methods were used to quantify antioxidant activity, with values ranging from 21.93 to 51.53 µmol Trolox 100 g-1 and 656.34 to 1021 µM ferrous sulfate 100 g-1, respectively. A drying temperature of 70°C combined with a thickness of 1 mm required a shorter drying time to reach the equilibrium moisture content, between 2 and 3 hours.

Abstract in English:

ABSTRACT. With technological advancements, particularly in image analysis, phenotyping can now be conducted more accurately, impartially, and non-destructively. However, distortions caused by different camera angles as well as environmental factors, such as lighting, lead to inaccurate results in image analysis. Therefore, a method for correcting these distortions is necessary to achieve more precise outcomes. The objective of this study was to develop an algorithm that corrects image distortion and improves tomato fruit phenotyping and to determine its efficiency. A photographic studio and a smartphone were used to capture the images. To test the developed algorithm, twelve 4 × 4 cm black squares were printed on A4 sheets, with four of these sheets placed inside the studio. Additionally, eight 3 × 3 cm yellow square sheets were used as reference objects to correct distortions. A total of 40 images were obtained with different camera angles. A multiple regression model was then adjusted and tested for each image to obtain a correction factor for distortions caused by varying camera angles. In the test images, higher estimates for the coefficient of variation and mean squared error were observed at the edges and lower ones at the center. After correcting the images using the adjusted regression model, uniformity in the estimates was achieved. The same behavior was observed when validating the model with images of tomato fruit. The coefficient of determination of the adjusted model was over 80%, indicating a high fit for the selected model. Therefore, the image distortion correction methodology ensures more accurate results in tomato fruit phenotyping.

Abstract in English:

ABSTRACT. In the Cerrado, soybean monoculture (Glycine max) and second-crop corn succession reduce soil quality and compromise long-term productivity. The application of conservation practices such as crop rotation, cover crops, and multifunctional rhizobacteria is essential for sustainable soybean cultivation in the region. This study aimed to evaluate how cover crop mixtures cultivated during the second crop season, in rotation with upland rice, and the co-inoculation of soybeans with multifunctional rhizobacteria affect soil quality (physical, chemical, and biological), as well as soybean nutrient uptake, biomass production, yield components, and final yield. The experiment was conducted in a randomized block design, arranged in a 7 x 2 = 14 factorial scheme with four replications. The treatments included five cover crop mixtures and two fallow systems: fallow 1 - rice/fallow/soybean (rotation between upland rice and soybean, without cover crops during the off-season) and fallow 2 - soybean/fallow/soybean (no rotation with upland rice and no cover crops in the off-season). All treatments with cover crop mixtures were also conducted under a rotational system, with soybean cultivated after upland rice in the summer season. Soybean seeds were either co-inoculated or not with Bacillus sp. (BRM 63573) and Serratia marcensces (BRM 32114). Rotation with upland rice and cover crop mixes provided higher P and Zn content in the soil, higher activity of the β-Glycosidase enzyme, lower density, higher total porosity, lower incidence of phytopathogenic fungi (Fusarium solani and Rhizoctonia solani), greater biomass production, greater macro and micronutrient content in the aerial part, greater number of pods per plant and grain yield of the soybean crop concerning the areas that remained fallow. Fallow 2 (soybean/fallow/soybean) provided lower results for most of the analyzed variables (soil attributes, nutrient uptake, biomass production, grain yield and soybean yield components). Co-inoculation provided higher soil microporosity, lower density of the phytopathogenic fungus (Fusarium oxysporum) in the soil, greater biomass production and nutrient accumulation in the shoot of soybean plants, compared to treatment without co-inoculation.

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ABSTRACT. Agrobiodiversity can promote food and nutritional security. Agrobiodiverse agricultural systems are frequently found on small family coffee farms with distinct economic, social, and environmental characteristics in Central and South America. Brazil is the world’s largest coffee producer, with the state of Minas Gerais, especially the Zona da Mata mesoregion, being the country’s leading producer, recognized for its small mountainous family coffee farms. The presence and composition of home gardens in Brazilian family coffee farms still lack objective and measurable assessments of species agrobiodiversity. Given the limited knowledge about agrobiodiversity at these properties, this study aimed to: (i) evaluate plant communities and agrobiodiversity in the home gardens of family coffee farms in Zona da Mata of Minas Gerais State, Brazil; and (ii) document the use of plant species in these home garden communities. Evaluations were conducted in the home gardens of five family coffee farms located in the Zona da Mata region of Minas Gerais State, Brazil, with identification, quantification, and determination of Simpson, Shannon-Wiener, Pielou’s equitability, Morisita, alpha diversity, species-individual curve, and species use indices across 0.1-ha plots per farm. Significant variations in the number of individuals were recorded with the presence of fruit-bearing and vegetable species in the evaluated home gardens. There were notable differences in species compositions and agrobiodiversity indices of the home gardens of family coffee farms. Considerable plant diversity and species richness were observed in all home gardens, primarily associated with food, commercial, medicinal, and ornamental uses, contributing to the social function of the land and the preservation of plant diversity.

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ABSTRACT. The use of cover crops during the winter period is the foundation of the no-till system and provides physical, chemical, and biological benefits to the soil. A high biomass input from cover crops and benefits related to nutrient cycling also enhance the presence of beneficial soil microorganisms. Thus, this study aimed to evaluate dry matter phytomass production, the soil coverage curve with cover crops, and the decomposition curve of dry matter phytomass in monoculture and cover crop mixtures in a subtropical environment. The following cover crop treatments were evaluated during the winters of 2022 and 2023 using a randomized block experimental design: black oat, rye, common vetch, forage radish, black oat + common vetch, black oat + forage radish, black oat + common vetch + forage radish, rye + common vetch, rye + forage radish, and rye + common vetch + forage radish. Dry matter phytomass production, soil coverage, and dry matter phytomass decomposition were measured using the litter bag method. Black oat and forage radish in monoculture stood out for their dry matter phytomass production, and forage radish excelled in mixed treatments, presenting values exceeding 50% of the composition in all cases. Soil coverage was adequate for black oat, rye, common vetch, and forage radish in monoculture and their intercropping systems. After 150 days of decomposition, black oat and rye exhibited the lowest decomposition rates, and the cover crop mixtures showed intermediate decomposition rates, confirming their suitability as autumn/winter cover crops in subtropical environments.

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ABSTRACT. Approximately 85000 hectares of popcorn, which is a C4 glycophytic and salt-sensitive crop, is cultivated in Brazil. Agricultural land area is decreasing because of increasing population and salinity stress, leading scientists to devise a means to develop salt-tolerant crops using genetic approaches. This study was carried out to determine the most suitable NaCl concentration for screening popcorn inbred lines for salt tolerance. Four NaCl solutions (0, 60, 120, and 180 mmol L-1) were used on four popcorn inbred lines in a completely randomized design. The experimental treatments were replicated four times in a seed-germinating chamber over seven days. Twenty-five seeds from each line were treated with Maxim® before being placed on germination paper and soaked in an appropriate NaCl solution. Significant (p < 0.05) responses of the inbred lines to different NaCl concentrations in terms of shoot length, root length, fresh and dry shoot and root weight, root diameter, root surface area and germination percentage were observed. The salt tolerance index based on dry seedling weight was significantly correlated with the other traits under 60 and 120 mmol L-1 NaCl. The most concentrated NaCl solution (180 mmol L-1) resulted in the greatest reduction in the performance of the inbred lines, indicating that NaCl is toxic to the inbred lines evaluated. Regression analysis indicated that shoot length and root length are the most significant traits for assessing salt stress tolerance in popcorn inbred lines. The results suggest that NaCl solutions of 60 and 120 mmol L-1 could be used for screening salt tolerance in popcorn, as these provide a strong ability to distinguish among the inbred lines studied.

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ABSTRACT. Phenological studies are fundamental for species management and conservation and support research into genetic improvement by providing insights into plant life cycles and their relationship with phenophases and environmental conditions. This study aimed to determine the environmental variables and their influence on the vegetative and reproductive phenological patterns of Hymenaea martiana Hayne. Field observations were carried out in five areas located in the municipality of Areia, Paraíba State, Brazil. Between May 2021 and April 2023, the phenological events of budding, senescence, flower bud, flowering, and fruiting were assessed every 30 days. Statistical analyses were circular to verify the occurrence of the phenophase periods, their concentration, seasonality, and duration, and Spearman correlations were used to test the relationships between meteorological variables during the period and the phenophases. The patterns of budding, senescence, flower bud, and flowering phenophases of H. martiana were seasonal, with an annual periodicity and a continuous fruiting pattern. The average dates of occurrence of the budding phenophase were August (area 2), October (areas 1, 4, and 5), and November (area 3). The average date for senescence was July (area 2) and August (areas 1 and 3-5). The average date for the flower bud phase was November (area 5) and December (areas 1-4). Flowering occurred in January (areas 3 and 4), March (area 2), and December (areas 1 and 5). Rainfall and temperature had a significant impact on the period and occurrence of vegetative and reproductive phenological events in H. martiana. Under highland marsh conditions, H. martiana fruit should be collected in October, November, and December.

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ABSTRACT. Zinc is an essential micronutrient for both humans and plants. In humans, it plays a vital role in various biological functions, as a component of approximately 300 proteins, with a recommended daily intake of 15 mg. About one-third of the global population faces zinc deficiency. In plants, zinc is crucial for phytohormone and carbohydrate pathways. Biofortification of staple crops is an efficient and sustainable method for addressing zinc deficiency. Allium schoenoprasum L., commonly known as chives, is a promising candidate for zinc biofortification due to its widespread use in Brazil and ease of cultivation. This study determined the responsiveness of chives to agronomic biofortification with zinc and the impact of biofortification on biochemical and nutritional parameters. Zinc was applied via foliar fertilization at rates of 0.0, 0.25, 0.5, 1, 1.5, 3, 6, and 12 kg ha-1. The following parameters were assessed: fresh weight, shoot height, collar diameter, root and aerial part dry weight, and contents of selected sugars, free amino acids, macronutrients, micronutrients, chlorophylls, carotenoids, flavonoids, and phenolics. Linear regression and analysis of variance were performed using SigmaPlot software. The application of 6 kg ha⁻¹ resulted in a 248% increase in the zinc content and an average increase of 34% in nitrogen, phosphorus, potassium, calcium, magnesium, manganese, sulfur, copper, and boron compared to the control. An application rate of 0.5 kg ha⁻¹ led to a 26% average increase in plant growth. Thus, 6 kg ha⁻¹ of zinc is recommended for biofortifying Allium schoenoprasum L., as this concentration significantly increased the zinc content without severely impacting plant growth.

Abstract in English:

ABSTRACT. Spodoptera cosmioides is a polyphagous pest insect with significant destructive potential and increasing economic importance in intensive agriculture in tropical areas. Biological control that employs genes from Bacillus thuringiensis (Bt) encoding multiple insecticidal proteins has demonstrated high efficacy. Therefore, the objective of this study was to evaluate the isolated toxicities of various Cry1 and Vip3Aa proteins from Bt and their interactions, aiming at the control and management of S. cosmioides. The Cry1Ba, Cry1Ca, Cry1Ea, and Vip3Aa proteins were obtained from induced recombinant Escherichia coli clones, analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), quantified, and incorporated into an artificial diet for bioassays to estimate the 50% and 90% lethal oncentrations (LC50 and LC90, respectively) of these proteins when tested individually and in combination. The LC50 values of the four toxins ranged 3.46-2,096.9 ng cm-2. The LC90 values ranged 53.13-170.81 ng cm-2, although in two cases it was not possible to estimate them as the values exceeded the maximum concentration testes. The SDS-PAGE revealed that the six protein combinations were evenly distributed, with three showing a synergism factor (SF) > 1 and three a SF < 1. Our results underscore the distinct modes of action of the tested proteins, as demonstrated by the occurrence of both synergistic and antagonistic interactions within the host. Understanding the mode of action of Bt proteins is fundamental to enhancing and sustaining their efficacy against pests. Therefore, the use of proteins that bind to independent sites is a cumulative strategy that can improve the performance of integrated pest management programs. This approach enables the development of novel, Bt-pyramided plants, thereby effectively managing and preventing the development of resistance in S. cosmioides.

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ABSTRACT. This study evaluated the response of ‘Palmer’ mango trees to the foliar application of potassium (K) and humic substances in the Brazilian semi-arid region. The experiment was carried out using a randomized block design with five treatments: control, potassium chloride, potassium nitrate, humic substances, and a combination of potassium nitrate and humic substances. The leaf nutrient content, fruit yield, and physicochemical quality were assessed. Potassium nitrate improved the leaf K content and yield, and humic substances enhanced the fruit firmness and total soluble solids. The combined treatment provided the most balanced improvement across parameters. The findings support foliar fertilization as a viable technique for optimizing nutrient management and fruit quality in mango orchards under semi-arid conditions.

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ABSTRACT. Orange (Citrus sinensis L. Osbeck) is one of the most widely known fruit trees, and Brazil is the largest orange-producing country and the leading concentrated orange juice exporter worldwide. However, the citrus industry faces significant phytosanitary challenges, necessitating the diversification of scion and rootstock varieties to address abiotic and biotic stress and to sustainably achieve higher yields. Therefore, research focused on enhancing the genetic base of orchards and evaluating the agronomic potential of newly developed genotypes is essential for supporting and optimising production systems. In this context, this study aimed to evaluate the agronomic performance of eleven sweet orange cultivars grafted onto citrumelo rootstocks (‘Swingle’ and ‘F80-5’) under the soil and climate conditions of Tangará da Serra, Mato Grosso State, Brazil. The experiment was conducted at Boitanga Farm using a randomised block design in a 2 × 11 factorial arrangement (2 rootstocks and 11 scion cultivars), with 4 replications and 1 plant per plot. Plant production, biometric characteristics, fruit physical and chemical quality, and bioactive compounds were evaluated. Orange scions grafted onto ‘Swingle’ citrumelo rootstock exhibited canopies with a higher vegetative vigour index, but no commercial fruit production when evaluated 36 months after planting. Based on the first crop season, the ‘F80-5’ citrumelo rootstock with ‘Valência Taquari’, ‘Pêra Bianchini’, ‘Seleta Vermelha’, and ‘Baianinha-Pre’ scions resulted in the highest yield. ‘Pêra Bianchini’ had the highest juice yield and is recommended for the juice industry.

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ABSTRACT. The objectives of this study were to determine whether there is variability in the protein-nutritional composition of grains among single-cross, triple-cross, and double-cross hybrids and OPVs and different sowing dates and to develop models for amino acid prediction based on the CP content. A total of 773 grain samples from four maize cross-types cultivated with ten sowing dates were evaluated by Near Infrared Reflectance Spectroscopy. Descriptive statistics were applied and simple linear regression models were developed for protein-nutritional traits for different cross-types and sowing dates. Principal component analysis was used to group data on the protein-nutritional composition of grains and meteorological variables, by cross-types and by sowing dates. Open-pollinated varieties of maize had the highest means of crude protein, lysine, methionine, cystine, threonine, tryptophan, valine, isoleucine, leucine, histidine and arginine in the grains, compared to single-cross, triple-cross and double-cross hybrids regardless of the sowing date. Methionine, cystine, threonine, tryptophan, valine, isoleucine, leucine, histidine and arginine in maize grains can be predicted from their crude protein with high precision in single-cross, triple-cross and double-cross hybrids and open-pollinated varieties.

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ABSTRACT. The objective of this study was to evaluate the resistance of ten maize varieties to Dalbulus maidis. Under choice and no-choice conditions, the attractiveness of maize plants to D. maidis for feeding, shelter, and oviposition was assessed. The developmental effects on different life stages of D. maidis across maize varieties, as well as the damage caused to maize plants, were also evaluated. The varieties IAC AIRAN and Amarelo Astecão recorded the highest adult preference means, whereas Pipoca Roxo Kika was the least preferred. Under choice conditions, no statistically significant difference was observed regarding oviposition. However, under no-choice tests, a higher number of eggs were laid on Al Bandeirante compared with Amarelo Astecão. Insects maintained on NS 90 PRO 2 plants exhibited the longest nymphal period, while those on Pipoca Roxo Kika had the longest overall developmental period compared with insects on Branco Pedro 2. Insects reared on Amarelo Laleska, Amarelo Astecão, NS 90 PRO 2, Pipoca Roxo Kika, and Vermelho Pedro showed shorter adult longevity than those reared on Al Bandeirante. There was no statistically significant difference in percentage growth or visual damage scale data. A dendrogram indicated the formation of two major groups: i) susceptible varieties and ii) resistant varieties. The results of this study suggest that potential sources of resistance in maize plants were identified, which may assist in the management of D. maidis, support the selection of suitable materials for field cultivation, and guide maize breeding programs.

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ABSTRACT. Banana is an important tropical crop; however, its acclimatization phase still exhibits high mortality rates and limited nutrient uptake. Considering the potential of arbuscular mycorrhizal fungi (AMF) to enhance seedling establishment by increasing nutrient acquisition, biomass accumulation, and stress tolerance, this study evaluated the effects of inoculation with AMF on the growth of micropropagated banana seedlings under greenhouse conditions. Two experiments were conducted: i) micropropagated seedlings were grown in sterilized coconut fibre substrate and inoculated with five AMF isolates (Acaulospora foveata, Gigaspora margarita, Glomus formosanum, Rhizoglomus clarum, and Cetraspora pellucida), a commercial bioinoculant, mineral fertilizer, and a non-inoculated control; and ii) micropropagated seedlings were transplanted into sterile or non-sterile soil and subjected to the same treatments. Growth, nutrient accumulation, root colonization, and spore density were assessed. Inoculation with Cetraspora pellucida and Acaulospora foveata significantly increased the shoot and root dry mass, as well as the concentrations of N, Ca, Mg, S, Fe, and Cu, achieving levels comparable to those obtained with mineral fertilization. Cultivation in non-sterile soil enhanced the performance of micropropagated seedlings, suggesting synergistic interactions with the native microbiota. Regarding colonization and spore production, Acaulospora foveata and Rhizoglomus clarum were the most effective. Overall, these results indicate that AMF inoculation is an effective biotechnological strategy for optimizing the acclimatization and nutrition of micropropagated seedlings, reducing dependence on mineral fertilizers, and promoting sustainable nursery practices. Future studies should validate these findings under field conditions. Moreover, the results reveal the potential of this approach for integration with sustainable banana seedling production programs, demonstrating its operational applicability to tropical fruit cultivation systems.

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ABSTRACT. Despite the nutritional and commercial significance of microgreens, well-defined technical parameters have yet to be established for their cultivation under different climatic conditions. This study aimed to determine the effects of seed density and nutrient concentration on mustard microgreens with soilless cultivation. The experiment was conducted in a greenhouse in Porto Alegre, Rio Grande do Sul State, Brazil, during the winter and spring of 2021. A randomized block experimental design was adopted, with 3 replications, using a 4×4 factorial scheme, consisting of 4 seed densities (50, 100, 150, and 200 g m-2) and 4 nutrient solution concentrations (0%, 50%, 100%, and 150%; corresponding to electrical conductivities of 0.15, 1.0, 2.0, and 3.0 dS m−1). Evaluated variables included the shoot height, fresh and dry shoot mass, and total soluble solids index. Winter cultivation was primarily affected by reduced radiation and lower temperatures in the protected environment. Under winter conditions in Rio Grande do Sul, mustard microgreens did not meet commercialization standards regardless of the seed density or nutrient concentration. In contrast, during spring, the recommended electrical conductivity was 2.00 dS m−1, and the optimal seed density was, at least, 150 g m−2.

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ABSTRACT. Fruit colour, a quality attribute of great importance for melon, is related to the accumulation of carotenoids, which are essential for human health as they are vitamin A precursors and vary in content, giving rise to different pulp colours. Thus, this study aimed to investigate the colour characteristics anPd expression of candidate genes involved in carotenoid metabolism in climacteric ‘Gaucho’ and non-climacteric ‘Eldorado’ melon fruit during development and ripening. The change in rind and pulp coloration in ‘Gaucho’ occurred suddenly in the last stages of maturation, whereas this transition occurred continuously and gradually in ‘Eldorado’. The expression of phytoene synthase 3 was higher in ‘Gaucho’ than in 'Eldorado' and remained constant throughout the developmental period. In addition, two carotene isomerase genes and one carotene hydroxylase gene showed higher expression in ‘Gaucho’, indicating the greater significance of these genes in the formation of aromatic compounds and other derivatives of carotenoid metabolism since they alone do not explain the formation of different colours in the cultivar Gaucho. This study contributes to our understanding of the carotenoid pathway in the Cucurbitaceae family and provides a foundation for future research on the manipulation of nutritional and commercial quality.

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ABSTRACT. During açaí pre-processing, blanching aims to eliminate the protozoan responsible for Chagas disease, which can be transmitted by ingesting contaminated açaí juice. In the municipality of Tomé-Açu, Pará State, Brazil, most açaí pre-processing and processing are performed small-scale local units. Each unit employs their own blanching method, which may modify the physical and chemical characteristics of the resulting juice (the final product). In this context, this study aimed to evaluate the physical and chemical properties of açaí after blanching in four small-scale processing units located in the municipality of Tomé-Açu, Pará State, Brazil. During each visit, a questionnaire addressing good açaí juice manufacturing practices was completed. In addition, açaí samples were collected from each processing unit before and after blanching. The samples were analyzed for their physical characteristics-length (a), width (b), thickness (c), geometric diameter (Dg), sphericity (S), and circularity (C)-and chemical characteristics, such as water content, pH, and soluble solids. The analyses showed that processing units that used water with lower temperatures after immersion in hot water produced products with greater variation in the physical properties. Furthermore, there was a reduction in pH and an increase in the water content of açaí after blanching, although these changes were not significant.

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ABSTRACT. 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.

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ABSTRACT. The replacement of native vegetation with nonnative vegetation for different land uses, which is a consequence of the intensification and expansion of agricultural production, significantly alters the dynamics of soil organic fractions. The aim of this study was to evaluate the changes in carbon and nitrogen contents and stocks, as well as the chemical fractions of organic matter, caused by different land uses in Cerrado areas. The selected areas were conventional tillage (CTS), no-tillage (NTS), eucalyptus cultivation (EC) and native Cerrado vegetation (NC) in the regions of Barreiras and Luís Eduardo Magalhães, Bahia State, Brazil. The highest carbon contents and stocks were found under NTS up to 10 cm, and these values, as well as those of EC, were equal to those found under NC below 10 cm. The same phenomenon was not verified for the nitrogen contents and stocks in the soil up to 20 cm deep. The values of carbon in the fulvic acid fraction (C-FAF) under NTS and EC were equal to those of NC up to 10 cm deep, but only EC was equal to NC below this layer. At the 10-20 cm depth, the C-FAF increased by 1.23 g kg-1 and 0.95 g kg-1 under NTS compared with those under EC and NC, respectively. With respect to the correlations between carbon fractionation and total organic carbon, the nonextractable humic fraction (C-HUM) had the strongest correlation with the TOC content, with r2 = 96 (p < 0.001). Over time, the input of residues in the NTS and EC areas contributed to increasing soil carbon stocks and organic matter quality, with a recovery of up to 84% of the carbon in humin.

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ABSTRACT. In Brazil, Eucalyptus plantations occupy approximately 7.6 million hectares, of which 8% are located in the state of Bahia. In southern Bahia, these plantations are predominantly established on soils with cohesive horizons, characterized by high soil strength when dry and restricted pore connectivity when wet. These conditions reduce water, air, and nutrient fluxes, adversely affecting root development and plant growth. Subsoiling is a management practice commonly employed to mitigate these limitations; however, its effectiveness and persistence in modifying the physical attributes of naturally dense soils remain under debate. This study aimed to assess the effects of subsoiling on the physical quality of cohesive Argissolo Amarelo under Eucalyptus cultivation. Two sites were evaluated: one with Argissolo Amarelo distrófico típico (PA1) and another with Argissolo Amarelo distrocoeso fragipânico (PA2), both subsoiled to 0.60 m prior to planting. Soil samples were collected 6.5 years after planting in PA1 and 1 year after planting in PA2. Sampling was performed in the planting rows (0.20-0.25, 0.35-0.40, and 0.60-0.65 m) and the inter-rows (0.20-0.25 m). The following physical attributes were determined: bulk density, total porosity, the least limiting water range (LLWR), the water retention curve and the pore size distribution. According to the results, subsoiling led to sustained improvements in soil physical quality. The subsoiled layers exhibited lower bulk density, increased macroporosity, and a higher LLWR. Additionally, pore distribution was altered, with a higher proportion of cryptopores in non-subsoiled layers. The surface layers showed greater water retention at high matric potentials in the planting rows and low potentials in the inter-rows. These findings underscore the potential of subsoiling to enhance the physical functionality of cohesive soils under Eucalyptus, with effects that persist for multiple years post-subsoiling.

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ABSTRACT. Despite the improvements in soil properties and grain yield obtained by using cover crops, there is little information on their long-term effects and associated nitrogen topdressing fertilization on subsequent crops grown in the same field. Thus, this study aimed to determine the effects of cover crops and nitrogen topdressing fertilization on the soil chemical and physical properties and yield of subsequent grain crops over eight years. The experiment was conducted on soil classified as Oxisol in southern Brazil using a randomized block design in split plots, with five replications. The main plots were divided by winter cover crop (black oat (Avena strigosa Schreb), and pea (Pisum sativum ssp. arvense)), and the subplots had differing nitrogen topdressing application rates (0, 25, 50, 75, and 100 kg N ha−1) and summer grain crops (bean (Phaseolus vulgaris), maize (Zea mays L.), and soybean (Glycine max (L.) Merr.)). In March 2022, after the eighth year of crop rotation, samples were collected in 0-5, 5-10, 10-20, and 20-30 cm soil layers to determine the chemical properties and in 0-5, 5-10, 10-20, and 20-40 cm layers to determine the physical properties. The pH, phosphorus content, and organic matter values were not influenced by the cover crop. A higher soil potassium content was observed at depths of 0-5, 5-10, and 10-20 cm in oat. Oat also showed increased soil macroporosity compared to pea in the 20-30 cm layer. Pea only increased the grain yield in one season with bean and one season with maize. Nitrogen fertilization increased the yield in only some seasons, two seasons with bean and one season with maize. The results of this study can be used to guide cover crop management in no-tillage cropping systems to maximize the positive effects on soil quality.

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ABSTRACT. Cadmium (Cd) and lead (Pb) contamination in agricultural and urban soils poses significant environmental and human health risks, especially in areas impacted by metallurgical waste. In this study, the efficacy of four biochars produced from rice straw (RSB), sugarcane bagasse (SBB), sewage sludge (SSB), and filter cake (FCB), in immobilizing Cd and Pb and improving soil chemical properties, was assessed. An incubation experiment was conducted using contaminated soil from Santo Amaro, Brazil, a site historically affected by lead smelting. Biochars were applied at 10% (w/w), and their effects on soil pH, nutrient availability, organic matter (SOM), and metal fractionation were evaluated. Compared with the control treatment, the SBB and FCB treatments significantly reduced the availability of Cd (~30%) and Pb (~20%). These biochars also increased phosphorus (P) availability and increased the SOM content. Sequential extraction indicated a shift of Cd and Pb from labile to more stable forms, particularly the reducible and residual fractions, suggesting improved long-term immobilization. The superior performance of SBB and FCB was attributed to their higher SOM and P contents, as well as functional groups that promote metal complexation. Overall, the findings demonstrate the potential of nutrient-rich, waste-derived biochars as a sustainable and cost-effective solution for the remediation of heavy metal-contaminated soils. The results highlight the importance of selecting biochars based on feedstock characteristics and underscore the need for field-based studies to evaluate their long-term stability and the effects on metal uptake by plants.

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ABSTRACT. Due to its territorial dimensions and the diversity of geoenvironments, the State of Ceará presents a wide variety of soils. This study aimed to carry out the disaggregation of soil mapping units from the survey conducted for the State of Ceará at a 1:100,000 scale, indicating the spatial distribution and percentage of occurrence of the main soil classes throughout the state and relating them to their potential and limitations for agricultural use. Soil mapping data from the 1:100,000 survey of Ceará were standardized in a PostGIS database and integrated into QGIS for spatial-attribute processing. The mapping units were proportionally disaggregated into individual soil classes using SQL queries, generating vector layers with calculated areas and Brazilian Soil Classification System-standardized symbology, excluding water bodies, rocky outcrops, and terrain types. Neossolos, Argissolos, Luvissolos, and Planossolos were among the main identified classes, each with distinct characteristics that directly impact their use and management. Understanding the characteristics of soils in Ceará’s territory is crucial for adopting sustainable agricultural practices and preventing degradation processes.