Abstract in English:

ABSTRACT. In science, technology and assistance to smallholder farming or large crop acreages of Stevia rebaudiana is necessary to report data using information components to facilitate investors to understand the local field conditions to make assertive economic decisions for long periods. Stevia rebaudiana produces consistent natural sweeteners with safe performance as reported in a multitude of scientific publications. The leaf chemicals components are suitable to humans with healthy disorders affected by the consumption of sugarcane or many other industrial sweeteners. Otherwise, aspects related to the agriculture of sweeteners production still require additional discussion to improve qualitative and quantitative traits necessary for cultivating cost-effective crops. The current text highlighted some agriculture decisions necessary to make the crop more profitable to investors as researchers, agriculture influencers, farmer assistants and consultants of companies looking for alternatives within agro-ecological systems.

Abstract in English:

ABSTRACT. Variable height is commonly used as an input attribute to estimate other variables. Thus, to ensure less susceptibility to errors, it is necessary to obtain the variable height correctly. In addition to DBH, hypsometric relationships are influenced by several factors, such as site, age, genetic variation, and silvicultural practices. The inclusion of these factors in hypsometric models can lead to a gain in the quality of the estimates and in the biological realism. The objective of this study was to propose and evaluate the performance of a model extracted from artificial neural network training and of new models to estimate the total height of eucalyptus trees. The data used in this study originated from temporary forest inventories conducted in eucalyptus stands in Minas Gerais, Brazil. A multilayer perceptron artificial neural network was trained, and a nonlinear equation was extracted from the best-performing network to predict the total heights of trees. New linear and nonlinear hypsometric models were constructed and fit considering variables related to individual trees (DBH) and stands (plot basal area, age and site index). The new hypsometric models proposed in this study showed satisfactory performance and are effective for estimating the total heights of eucalyptus trees, particularly the model extracted from the artificial neural network and the nonlinear model.

Abstract in English:

ABSTRACT. The increasing use of genomic selection (GS) in plant and animal breeding programs has led to the development of software that fits models based on unique scenarios. Accordingly, several R packages have been developed for GS. The lmekin function from the coxme R package was one of the first functions implemented in R to fit models with random family effects using the pedigree-based relationship matrix. The function allows the user to provide the covariance structures for the random effects; thus, the GBLUP model can be fitted. This fitting process consists of replacing, in the traditional BLUP model, the additive relationship matrix derived from a pedigree by the additive relationship matrix derived from markers. Thus, the objective of this study was to employ the lmekin function in the context of genomic prediction by comparing the results of this function with those obtained using five R packages for GS: rrBLUP, BGLR, sommer, lme4qtl, and lme4GS. The comparisons were performed considering the computational times and predicted values for a wheat dataset and simulated big data. In addition, we implemented a 5-fold cross-validation scheme through considering the values predicted by the lmekin function for the wheat dataset. The results indicated that the lmekin function was effective in predicting genomic breeding values considering multiple random effects and relatively small sample sizes. The rrBLUP package processed the fastest for the scenario with only one genetic random effect, and the high temporal efficiency of the sommer package was confirmed for the scenario with more than one genetic random effect. Differences in computational times occurred because of the different algorithms implemented in the packages to estimate the variance components.

Abstract in English:

ABSTRACT. Nonlinear regression models represent an alternative way to describe plant growth. In this study, we aimed to model the growth of linseed using four methods for data collection (longitudinal, mean, random, and cross-sectional) and fitting the logistic and Von Bertalanffy nonlinear regression models. The data came from experiments conducted between 2014 and 2020 in the municipality of Curitibanos, Santa Catarina, Brazil. The study had a randomized block design, with experimental units consisting of six lines, 5.0 m long and 3.0 m wide, containing the varieties and cultivars of linseed with four replicates. We performed weekly assessments of the number of secondary stems and plant height and measured total dry mass fortnightly. After tabulation, the data were analyzed using the four methods, and the logistic and Von Bertalanffy models were fitted. The logistic model for the plant height variable exhibited the best performance using the longitudinal, mean, and cross-sectional methods. It was an alternative approach that reduced the time and labor required to conduct the experiment.

Abstract in English:

ABSTRACT. Imputation methods were developed to define estimates for missing data and hence solve possible problems generated by the loss of this information. This study aims to assess whether data variability influences the results obtained after applying an imputation method. Incomplete databases were generated from complete real databases of experiments of tomato plants conducted using the randomized block design with three replications and 12 treatments by removing different amounts of data. The evaluated variables consisted of fruit weight per plant, number of fruits per plant, and average fruit length and width, forming eight balanced databases. Subsequently, the distribution-free multiple imputation method was applied, generating complete databases from imputation. The number of missing information influenced the accuracy measures for the data in this study. Data imputation was inadequate when there was high variability but more precise and accurate in cases of low variability. It confirmed the importance of assessing data variability before choosing to apply the imputation method.

Abstract in English:

ABSTRACT. Excessive changes in factor levels can lead to a high cost in practice and hinder the conduction of experiments, in addition to adding a higher computational cost and loss of the orthogonality property, resulting in numerical problems in estimating the parameters of a model. The sequential specification of experimental points, seen as treatments in a 2k factorial design, results in a high-order bias in some factors, which is caused by the accumulation of −1 or +1 signals. This study aimed to propose new designs generated by the simulated annealing technique, respecting the main A-optimal and D-optimal optimality criteria as random execution orders that minimize the order bias. This approach allowed the generation of 24 and 25 factorials, which were compared to the designs in standard order. The simulated annealing technique is a viable method to generate optimal designs with the same efficiency as the usual designs to obtain A-optimal and D-optimal designs with new execution orders, which minimize the effect of order bias relative to standard order designs. Regarding efficiency, the generated designs were precise in the variance of model parameter estimates, similar to the original designs.

Abstract in English:

ABSTRACT. We tested the hypothesis that the increase in soil stiffness, induced by variations in bulk density and water content at the tire-soil contact interface, causes a reduction in the contact area. For this, we examined the contact area from different tire-ground contact scenarios and compared the measurements and simulations using a contact area description model. Front and rear tractor tires were used for the measurement of the contact area under tilled soil, sugarcane field, unpaved road, and paved ground scenarios, which induced different bulk densities and water content levels. The results revealed that soil stiffness reduced the tire-soil contact area. The tire-soil contact area increased as the water content increased and the bulk density was reduced. For the front tractor tire, the theoretical contact area was similar to the values found for tilled soil, but there was a large difference between the measurements (2,200 cm2, for the tilled soil) and the theoretical estimates (3,100 cm2) for the rear tractor tire (likely induced by tire dimensions). Our results suggest that increases in soil stiffness reduce the tire-soil contact area. The higher the soil bulk density and the lower the soil moisture, the lower the contact area. The results also revealed that the tire tractor tread might reduce the contact at the hard surface, making the shape of the contact area more geometrically irregular and different from those predicted by models using regular geometry (e.g., cycles, ellipses, or rectangles). This study suggests that two-body (soil and tire) contact models for deformable surfaces should be used in future tire-soil contact models of agricultural field vehicles.

Abstract in English:

ABSTRACT. Citrus tristeza virus (CTV) can be transmitted by several aphid species in a semi-persistent mode, with Toxoptera citricida being the most efficient vector. In Brazil, mild CTV isolates are used for pre-immunization of citrus trees against severe isolates. We aimed to determine the capacity and efficiency of T. citricida in separating the viral complex into haplotypes from three well-characterized CTV isolates (PIAC, CS1, and Forte Rolândia). Single-aphid transmission assays were conducted to determine CTV transmission efficiency. The results showed that T. citricida transmitted only haplotypes from the PIAC and CS1 isolates, with efficiencies of 8 and 4%, respectively. Both isolates caused mild CTV symptoms in Brazil. However, isolate Forte Rolândia, which causes severe symptoms in citrus trees, was not transmitted by T. citricida. The detection of CTV haplotypes from PIAC and CS1 isolates in sweet orange (Citrus sinensis) plants after a single aphid transmission occurred at different time points. The first haplotype observed was from PIAC 150 days after citrus was challenged by a single aphid, followed by CS1 at day 210 after transmission. In addition, differences in the single-strand conformation polymorphism patterns between the CTV isolates and CTV haplotypes were determined, suggesting that an aphid can acquire and transmit only one CTV haplotype to citrus plants during phloem feeding. The study of the mechanism of transmission by the vector can increase our knowledge of the interactions among hosts, vectors, and pathogens, which are often neglected.

Abstract in English:

ABSTRACT. Cotesia flavipes parasitizes Diatraea saccharalis, a pest that causes major losses to sugarcane production. The mass production of C. flavipes and its subsequent release onto sugarcane is one form of biological control of D. saccharalis. An essential factor for successfully fighting this pest is the development of host diets that can increase the efficiency of C. flavipes production. Palm oil contains saturated fatty acids, unsaturated fatty acids, and polyunsaturated linoleic acid. However, little is known about the effects of palm oil on C. flavipes production in the laboratory. Different concentrations of palm oil were added to the D. saccharalis diet and its nutritional indices were analyzed. Subsequently, the production and sex ratio of C. flavipes were determined. Our results indicated that the addition of higher palm oil concentrations to an artificial diet generated a high relative consumption rate (RCR) in D. saccharalis, and consequently a high relative metabolic rate (RMR), which resulted in a lower production of the parasitoid. In contrast, the lowest palm oil concentration in the artificial diet generated a low RMR and resulted in high-efficiency conversion of ingested food (ECI), enabling D. saccharalis to yield more C. flavipes. This suggests that palm oil influences the quantity of D. saccharalis ingested, which determines the number of C. flavipes that will be generated. In this study, supplementation of a D. saccharalis diet with 0.25% palm oil increased the production of C. flavipes. Therefore, this level of palm oil supplementation can aid in the production of C. flavipes on a laboratory-scale. Further research, including increasing the number of parasitoids, must be performed to mass-produce the augmentative releases of C. flavipes to manage D. saccharalis.

Abstract in English:

ABSTRACT. Downy mildew is a major problem for grape growers, as this disease is difficult to control. Synthetic fungicides are used to treat downy mildew with handheld backpack and tractor sprayer applications, with high chemical exposure by operators. As important tools for maximising yield, application technologies must be studied to optimise control efficiency. The objective of this study was to evaluate the efficiency of fungicide spray application using Remotely Piloted Aircraft (RPA) for the control of downy mildew in grapevine, with different spray volumes. The study was divided into two experiments using 4 vine lines, 10 blocks and 5 treatments with different mixture volumes: Experiment 1 with RPA application of 5 mixture volumes - 0, 22, 44, 66, and 88 L ha−1; Experiment 2 with RPA application of 3 mixture volumes - 44, 66, and 88 L ha−1 and a backpack application of one mixture volume - 800 L ha−1. Coverage percentage, droplet density and volume median diameter (VMD) were evaluated. Downy mildew severity on grapevine leaves was assessed using visual analysis and a diagrammatic scale. The application of 44 L ha−1 provided the greatest coverage and droplet density in the upper and middle strata; however, the backpack application had a better droplet distribution than the RPA application. Treatments of 44 L ha−1 with RPA and backpack application (800 L ha−1) provided the best disease control. In the trellis system, RPA application must be improved because of the low coverage in the lower parts of the plant, and further studies with different spray nozzles and application heights are needed.

Abstract in English:

ABSTRACT. Predictive studies project the geographic distribution of species and can be used to infer climatic niches. However, only a few studies have been conducted on mites. This approach helps map areas with potential for the occurrence of endemic, threatened, or potentially invasive species. Panonychus ulmi (Tetranychidae) is of global economic importance, commonly associated with apple orchards and grapevines. Potential distribution modeling is used to predict areas with environmental suitability for the distribution of a species and/or group. Considering that predictive models on national or regional scales present better data reliability, the present study aimed to analyze the distribution of P. ulmi in Brazil through bioclimatic inferences. The presence of species, bioclimatic variables, and MaxEnt algorithm were used to define a predictive model. The median performance rate of the model was 0.992, indicating its robustness. The variable that made the greatest contribution to the model was the average temperature of the coldest quarter (Bio11). The predictive model of the ecological niche indicated that the southern region of Brazil is environmentally favorable for the adaptation of this mite. The data obtained helped us understand the geographical distribution of P. ulmi in Brazil, and climatically suitable areas for its occurrence were inferred. We believe that this tool can offer indirect assistance to the agricultural sector, especially the producers of apples and grapes in Brazil regarding the presence of P. ulmi.

Abstract in English:

ABSTRACT. Monosporascus cannonballus Pollack & Uecker and Macrophomina phaseolina Tassi (Goid) are phytopathogenic fungi responsible for causing "root rot and vine decline" in melon (Cucumis melo L.). Currently, cultural management practices are predominantly employed to control these pathogens, as the use of pesticides not only has detrimental environmental impacts but has also proven ineffective against them. These fungi have already undergone molecular characterization, and their genomes are now available, enabling the targeted search for protein targets. Therefore, this study aimed to identify novel target proteins that can serve as a foundation for the development of fungicides for effectively managing these pathogens. The genomes of M. cannonballus (assembly ASM415492v1) and M. phaseolina (assembly ASM2087553v1) were subjected to comprehensive analysis, filtration, and comparison. The proteomes of both fungi were clustered based on functional criteria, including putative and hypothetical functions, cell localization, and function-structure relationships. The selection process for homologs in the fungal genomes included a structural search. In the case of M. cannonballus, a total of 17,518 proteins were re-annotated, and among them, 13 candidate targets were identified. As for M. phaseolina, 30,226 initial proteins were analyzed, leading to the identification of 10 potential target proteins. This study thus provides new insights into the molecular functions of these potential targets, with the further validation of inhibitors through experimental methods holding promise for expanding our knowledge in this area.

Abstract in English:

ABSTRACT. Melon (Cucumis melo L.) is an important species in the cucurbit family with a large economic importance in the world. Two melon cultivars commercially important in Brazil are ‘Yellow’ and ‘Gaúcho’. In addition to their economic importance, these two cultivars display phenotypic differences in aroma, a major trait determining fruit quality. Volatile organic compounds (VOCs) impart the different aroma found in this fruit and their biosynthesis is associated with fatty acid and amino acid metabolism. Using RT-qPCR techniques, the expression of seven genes (CmLOX9, CmLOX18, CmBCAT1, CmArAT1, CmPDC1, CmADH1, and CmAAT1) was determined during ripening. The lipid pathway played a strong role in determining aroma composition in non-climacteric ‘Yellow’ melons. Most volatiles decreased during ripening, explaining the non-aromatic characteristic of this cultivar. In climacteric ‘Gaúcho’ melons, the amino acid pathway was the main one related to the biosynthesis of esters, which contribute to the aroma of this cultivar. Volatile products of the branched-chain amino acid pathway correlated with CmADH1 and CmAAT1 expression, demonstrating their role in volatile synthesis in this climacteric melon cultivar. In addition, CmPDC1 contributes to the formation of aldehydes at the beginning of this pathway.

Abstract in English:

ABSTRACT. Purslanes are frequently used in Brazil as potted plants and for landscaping because of their beautiful colored flowers. Despite their commercial importance, the genetic diversity within ornamental purslane remains largely unknown. Thus, a complete characterization of ornamental purslane resources is essential for its utilization since genetic variability is indispensable for the efficient development of new cultivars. This study aimed to evaluate genetic variability and recommend accessions to start a genetic breeding program for purslane (Portulaca umbraticola). Twenty purslane accessions were collected in public places in Areia City and Santa Rita City, Paraiba State, Brazil. The experiment was conducted in a greenhouse. An entirely randomized experimental design with 20 accessions and 5 replicates was utilized. Plants were evaluated for quantitative and qualitative traits. Data were submitted to analysis of variance and grouped by Scott-Knott’s criteria (p ≤ 0.05). The accessions were grouped using Tocher’s method based on the generalized Mahalanobis distance. Principal component analysis was also used to analyze the genetic divergence. There were significant differences (p ≤ 0.05) for all evaluated traits except for internode distance, plant height, and leaf length. The Scott-Knott criteria clustered the accessions into two groups for all traits except days to flowering (five groups). Tocher’s grouping based on Mahalanobis distance allowed the accessions to be separated into eight clusters. The genetic diversity observed in this study was supported by the consonance between the Tocher cluster method and the PC analyses. The traits that most contributed to genetic divergence among accessions were days to flowering (70.37%), flower length (6.10%), leaf width (3.89%), branch number (3.57%), and stem length (3.36%). Considering the criteria for use in outdoor spaces, wider plants with several large colored flowers, thicker stems, greener leaves, and earliness were interesting. Accessions 5, 7, 13, 14, 16, 18, and 20 should be selected as parents for further breeding programs. However, if the objective is to produce potted plants, dwarf plants with bigger leaves are desired, and accession 1 should be selected. This will create greater variability in segregating populations, which will increase the overall quality of ornamental use of this species. For those accessions with no reproductive verticils but with other excellent attributes, for example, high chlorophyll content breeding strategies, such as induced mutations or protoplast fusion, can be used.

Abstract in English:

ABSTRACT. This work aimed to estimate the genetic diversity in accessions of Opuntia ficus-indica collected in 13 regions of the semiarid region of Bahia. A total of 65 accessions were evaluated in a randomized complete block design, with three replications, at the Rio Seco experimental station belonging to the State University of Feira de Santana, Amélia Rodrigues-BA. Characterization of the accessions was made through the evaluation of 17 descriptors, namely 11 agronomic and six bromatological. The average Euclidean distance was used to estimate the genetic diversity among accessions. The shortest distances were obtained for accessions from the same collection site while the largest were observed in accessions 54 and 62 (10.32 DE) and 63 and 3 (10.22 DE). The analysis of canonical variables indicated cladodes total number (CTN), plant width (PW), CL, plant height (PH), ether extract (EE), and dry weight (DW) for discard as they presented the lowest contribution of the data set variation. Principal component analysis and K-means method were used to establish the clusters, and the formation of four groups was indicated. The first two principal components captured 52.5% of the total variation present in accessions. The descriptors with the greatest contribution to the variation observed in O. ficus-indica were total cladode photosynthetic area (TCPA), cladode area (CA), and cladodes width (CW). There is divergence between cactus forage accessions collected in the semiarid region of Bahia. This information will allow the use of these materials for the formation of segregating populations in the genetic improvement program of the State University of Feira de Santana. The accessions of groups III and IV should be explored by the forage cactus breeding program, as they presented greater productive potential.

Abstract in English:

ABSTRACT. Although acerola (Malpighia emarginata DC.) is a tropical fruit of high interest due to its high ascorbic acid content and attractive sensory attributes, fruit production is characterized by high genetic variability. Additionally, the use of new biometric tools for acerola breeding is scarce. This study aimed to estimate genetic parameters and the coefficient of repeatability, as well as determine the optimal number of fruits for quality trait analyses in different acerola genotypes, using different approaches. Twenty-three (Experiment I) and thirty-five (Experiment II) genotypes were evaluated in a randomized block design with four replicates and three plants per plot. Twenty fruits per plant were harvested and evaluated for the following quality traits: diameter, mass, skin color (lightness, chroma and hue), firmness, soluble solids (SS), titratable acidity (TA), SS/TA ratio, and ascorbic acid content. The genetic parameters and the coefficient of repeatability were estimated for each experiment using classical and Bayesian methods. Both approaches achieved similar results on estimating variance components, genetic parameters and the coefficient of repeatability. Genetic parameters showed favorable conditions for acerola selection. The coefficient of repeatability was high for all acerola quality traits. A total of 17 fruits are required for the effective selection of acerola genotypes with an accuracy of 95%.

Abstract in English:

ABSTRACT. This study evaluated the efficiency of genome-wide selection (GWS) based on regularized quantile regression (RQR) to obtain genomic growth curves based on genomic estimated breeding values (GEBV) of individuals with different probability distributions. The data were simulated and composed of 2,025 individuals from two generations and 435 markers randomly distributed across five chromosomes. The simulated phenotypes presented symmetrical, skewed, positive, and negative distributions. Data were analyzed using RQR considering nine quantiles (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9) and traditional methods of genomic selection (specifically, RR-BLUP, BLASSO, BayesA, and BayesB). In general, RQR-based estimation of the GEBV was efficient-at least for a quantile model, the results obtained were more accurate than those obtained by the other evaluated methodologies. Specifically, in the symmetrical-distribution scenario, the highest accuracy values were obtained for the parameters with the models RQR0.4, RQR0.3, and RQR0.4. For positive skewness, the models RQR0.2, RQR0.3, and RQR0.1 presented higher accuracy values, whereas for negative skewness, the best model was RQR0.9. Finally, the GEBV vectors obtained by RQR facilitated the construction of genomic growth curves at different levels of interest (quantiles), illustrating the weight-age relationship.

Abstract in English:

ABSTRACT. The Spodoptera frugiperda, is one of the most deleterious pests of popcorn and the identification of resistant genotypes is determinant in breeding programs. The objective of this study was to select popcorn genotypes resistant to S. frugiperda and the key traits related to the identification of resistance. The popcorn varieties UEM J1, Composto Márcia, Arachida, Composto Gaúcho, and Zapalote Chico (resistant check) were evaluated in a completely randomized design with 100 replications. The experimental unit consisted of one Petri dish, containing plant material and a caterpillar The following traits were evaluated: larval stage duration (LSt), food intake weight(IW), final larva weight (FW), mean larva weight (MW), feces (F), assimilated (A) and metabolized food weight (M), relative consumption rate (RCR), relative metabolic rate (RMR), relative growth rate (RGR), conversion efficiency of ingested food (CEI), apparent digestibility (AD), conversion efficiency of digested food (CED), and leaf area consumed (LAC). The diagnosis of multicollinearity, analysis of canonical variables, genetic divergence, hierarchical clustering, factor analysis and canonical correspondence analysis were carried out to perform multivariate analysis. After the multicollinearity test, the traits FW, IW, RCR, AD, and LAC were maintained for further analysis. The traits IW, FW and AD were determinant in the resistance by antixenosis expressed by the varieties Zapalote Chico and Arachida, for the varieties Composto Gaúcho and Composto Márcia the determining characteristics were RCR and LAC and for the variety UEM J1 the variable LAC showed greater importance. Variety Arachida was considered resistant to S. frugiperda by antixenosis and can be used in the future as a source of favorable alleles to breed resistant popcorn hybrids. The traits relative consumption rate, apparent digestibility and leaf area consumed were considered key traits in the identification of resistance against S. frugiperda in popcorn genotypes.

Abstract in English:

ABSTRACT. Lima bean cultivation has not received proper national and regional attention by research agencies, impairing the knowledge of the agronomic characteristics and its potential, information that is essential for the selection and launching of superior genotypes. The objective of this work was to characterize the seeds of 17 lima bean genotypes produced by family farmers in Paraíba State. The characterization was based on the descriptors for Phaseolus lunatus. A completely randomized design was used with 15 replicates. Data were submitted to analysis of variance with a subsequent grouping of means by the Scott-Knott test at 1% of probability. For analysis of the genetic diversity, the Tocher method was used based on the generalized Mahalanobis distance. There is variability among the genotypes. According to the means test, genotype 10 has a higher seed length, width, and weight. Considering the diversity among the groups and aiming to select light-colored and higher means of the evaluated traits, the selection of genotypes 8, 13, 4, and 10 is recommended to establish a breeding program that satisfies both the consumer and the producer.

Abstract in English:

ABSTRACT. In recent years, several efforts have been made to develop tomato cultivars displaying both late blight resistance and good organoleptic fruit quality. Selection indexes are considered the best option to perform genotype selection when many different traits are being considered to select genotypes as close to the desired ideotype as possible. Therefore, this study aimed at selecting late blight-resistant tomato families based on their fruit quality attributes using factor analysis and ideotype-design / best linear unbiased predictor (FAI-BLUP) index. For this purpose, we assessed the fruit quality parameters of 81 F3:5 tomato families previously selected as late blight resistant. The tomato cultivars Thaise, Argos, and Liberty were included in the trial as checks. The experimental arrangement consisted of complete randomized blocks with three replicates. Each plot was formed by five plants, three of which were used in the fruit quality assessment. The quality parameters assessed were fruit diameter, fruit length, fruit color (L, a*, C, and H), fruit firmness, titratable acidity, soluble solids content, hydrogen potential, and SS:TA ratio. Fruit quality data were analyzed using the mixed model methodology via REML/BLUP (restricted residual maximum likelihood / best linear unbiased prediction) to obtain BLUPs that were further subjected to the FAI-BLUP selection index. The FAI-BLUP was efficient in selecting late blight-resistant tomato genotypes based on their fruit quality attributes. Fourteen tomato families were classified as closest to the desirable ideotype for fruit quality. These genotypes should move on to the following stages of the tomato breeding program.

Abstract in English:

ABSTRACT. Zeyheria tuberculosa, a native species of Brazil known for its significant potential in silviculture and genetic improvement, holds prominence among various species. In this study, our objective was to assess the diversity, genetic structure, and feasibility of establishing a seedling seed orchard (SSO) for this species. A total of 71 progenies were collected from different locations and were used in our experiment in Ijaci - MG. We genotyped 92 individuals (nine families with eight individuals, two families with seven individuals, and one family with six individuals), specifically selecting those with the highest predicted genetic values, using ten ISSR primers. The molecular markers employed effectively detected polymorphism (PIC = 0.44). The population exhibited moderate to high genetic diversity, as evidenced by observed (AO = 2.00) and effective alleles (AE = 1.61), Nei's diversity index (H* = 0.35), and Shannon's diversity index (I* = 0.52). Molecular variance analysis indicated significant genetic differentiation between the progenies (Φst = 0.19), yet the majority of the variation was observed within them (80.1%). Employing a Bayesian approach, we identified the formation of two distinct genetic groups, further confirming the non-genetic structure of the population. These findings affirm the potential of the Z. tuberculosa progenies to contribute to the establishment of a seedling seed orchard, supporting genetic improvement strategies and the conservation of the species' genetic diversity.

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ABSTRACT. The objective of this study was to identify the genetic, phenotypic and environmental parameters related to chemical compounds associated with beverage quality in a conilon coffee collection, grown in an irrigated system, in the Cerrado. The experiment was carried out at Embrapa Cerrados using green grains harvested in two years from 84 genotypes of the cultivar Robusta Tropical. Caffeine content, protein, ether extract, total soluble solids, pH and titratable acidity were evaluated. The data were subjected to analysis of variance. Significant differences were observed at 1% probability among accessions for all evaluated chemical characteristics in both harvest years. The high heritability, genetic coefficients of variation and selective accuracy reveal the potential for achieving genetic gains via the selection of genotypes adapted to the irrigated system in the Cerrado combined with high beverage quality.

Abstract in English:

ABSTRACT. Jangada is a municipality in the Baixada Cuiabana region, State of Mato Grosso, Brazil. This study aimed to evaluate the collection of local cassava conserved by four traditional communities of Jangada in terms of ethnobotanical/socioeconomic and genetic aspects. Socioeconomic and ethnobotanical analyses were carried out with 40 farmers using qualitative techniques and descriptive statistics. Seven microsatellite markers were used for genetic analysis. A total of 182 cassava citations were verified, 31 of which were different. The Broto Branco variety was the most frequent (94.3%), followed by Vermelha Gaiadeira and Liberata (82.9 and 77.1%, respectively). The calculated median age for farmers was 56 years. Spearman’s coefficient indicated a positive correlation between the increase in farmer’s age and the number of cultivated local varieties. Few varieties are planted by many farmers, and most are planted by few farmers. High genetic diversity was observed, and most of the variability occurred within communities (88%). Two groups were formed in the cluster analysis, with two communities in each group. The propagule circulation network helped to understand the genetic similarity of communities with the closest geographic location. Cassava cultivation plays an important role in the studied communities, which maintain a high ethnobotanical and genetic diversity and relevant knowledge about the cultivated varieties.

Abstract in English:

ABSTRACT. One of the domains of genetic enhancement that has extensively employed both simulation and authentic data is Biometrics. Selecting efficient models for the Genome-Wide Selection (GWS) process using molecular markers (SNPs) presents several challenges. Among these challenges is the effective identification of the optimal model for fitting a given dataset. To contribute to this endeavor, this paper's primary objective is to assess the predictive accuracy of nine (9) distinct models, each following different paradigms within the realm of Biometrics. The data employed in this study were generated through simulation, encompassing the primary issues encountered in this field of research, including high dimensionality, nonlinearity, and multicollinearity. As the primary findings, notable observations include the enhancement of predictive efficiency as data noise decreases, the predominance of the tree paradigm (for low noise levels, BOO), and the efficacy of the neural network paradigm (for high noise levels, RBF).

Abstract in English:

ABSTRACT. Lettuce (Lactuca sativa L.) is the most consumed leafy vegetable in Brazil. It is cultivated using at least four distinct systems, the most common of which are conventional and hydroponic systems. These systems provide different cultivation conditions for plants, causing physiological changes that are important for commercial production, such as nutrient uptake and biomass accumulation. However, only a few studies have compared the physiological aspects of these two cultivation systems. The objective of this study was to evaluate the physiological behavior of ‘Rubinela’ lettuce plants grown in hydroponic and conventional pot systems, by comparing dry mass (DM) and fresh mass (FM) production, number of leaves (NF), stomatal density, and contents of chlorophyll, carotenoids, anthocyanin, sugars, and starch. Plants cultivated in hydroponic systems presented significant differences in chlorophyll content, producing more biomass than plants cultivated in conventional pot systems, probably because of better nutritional conditions, primarily with respect to macronutrients, provided by the nutrient solution of the hydroponic system. The lower water availability encountered by plants cultivated in conventional pot systems influenced the increased sugar and starch concentrations, as well as the anthocyanin content, which may be a strategy to mitigate the possible damage caused by hydric stress conditions.

Abstract in English:

ABSTRACT. Bahiagrass (Paspalum notatum Flügge) is an important forage in South America and the United States because of its high palatability, resistance to trampling and grazing, and tolerance to cold, but it exhibits low seed yield and poor seed quality. Previous studies reported improvements in forage production and nutritive value in hybrids and ecotypes; however, information about seed yield and quality in forage bahiagrass is limited. This study aimed to characterize the seed yield and quality of nine P. notatum intraspecific hybrids and three controls: P. notatum ecotypes V4 and Bagual and cultivar Pensacola. Inflorescence density, 1,000-seed weight, seed yield and germination rate decreased in year 2 influenced by weather conditions and ergot. Seed yield ranged from 139 (Pensacola) to 1,158 (Bagual) kg ha-1 among all entries, where Bagual, C18, and V4 produced more than 974 kg ha-1, which was approximately seven times more than Pensacola. Bagual, C18, V4, 336, C15, 225, and D3 showed germination rates greater than 83%. In conclusion, Bagual had the highest seed yield and germination rate, whereas hybrids C18 and 336 showed high seed yield, 1,000-seed weight, and germination rate in both years. Bagual, C18, and 336 should be used in future breeding programs to improve seed production traits. Our study revealed that selection for seed production traits can result in improvements in seed yield and quality in bahiagrass.

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ABSTRACT. Invasive species threaten crops and ecosystems worldwide. Therefore, we sought to understand the relationship between the geographic distribution of species populations and the characteristics of seeds using new techniques such as seed image analysis, multivariate analysis, and machine learning. This study aimed to characterize Leucaena leucocephala (Lam.) de Wit. seeds from spatially dispersed populations using digital images and analyzed their implications for genetic studies. Seed size and shape descriptors were obtained using image analysis of the five populations. Several analyses were performed including descriptive statistics, principal components, Euclidean distance, Mantel correlation test, and supervised machine learning. This image analysis technique proved to be efficient in detecting biometric differences in L. leucocephala seeds from spatially dispersed populations. This method revealed that spatially dispersed L. leucocephala populations had different biometric seed patterns that can be used in studies of population genetic divergence. We observed that it is possible to identify the origin of the seeds from the biometric characters with 80.4% accuracy (Kappa statistic 0.755) when we applied the decision tree algorithm. Digital imaging analysis associated with machine learning is promising for discriminating forest tree populations, supporting management activities, and studying population genetic divergence. This technique contributes to the understanding of genotype-environment interactions and consequently identifies the ability of an invasive species to spread in a new area, making it possible to track and monitor the flow of seeds between populations and other sites.

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ABSTRACT. Fig orchard expansion requires knowledge of the thermal requirements of genotypes available in different climatic regions. The budburst of fig cultivars was assessed by biological single-node cutting and exposure to artificial chilling. Cuttings from five cultivars were collected during two crop seasons, subsequently packaged in a horizontal position in a cold chamber (8 ± 0.5ºC), and artificially chilled for 0, 40, 80, 120, and 160h. Cuttings were preserved under controlled conditions (23 ± 1°C, RH 85%, and 16h photoperiod). The variables evaluated were the budding velocity, average time and final rate of sprouting, vigorous shoot rate, and average time to leaf opening. The single-node cutting test allowed the assessment of dormancy, which is influenced by the accumulation of chilling in each crop season. The average time and final budding rate varied depending on the temperature requirements for budding. The cultivars were classified on an increasing scale according to their chilling requirements as follows: Pingo de Mel < Roxo de Valinhos < Brown Turkey < White Genova < Troyano. The traditional cultivar in Brazil is Roxo de Valinhos, but all of the cultivars studied had the potential to diversify the fig orchards in this region.

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ABSTRACT. Conservation practices such as no-tillage are necessary to maintain, and/or improve agricultural soil quality. However, straw formation and maintenance in tropical regions is a limiting factor to adopting this system. In this sense, this research aimed to study the effect of cover crops on straw formation, soil quality indicators, and cowpea yield under no-tillage in the Amazon savanna. Two experiments were carried out in consecutive years, on a Latossolo Amarelo. The treatments consisted of the straw of cover crops in a single (S) and intercrop (I) system, as follows: Urochloa brizantha (UBS), Pennisetum glaucum (PGS), Crotalaria juncea (CJS), Canavalia ensiformis (CES), Mucuna aterrima (MAS), U. brizantha and C. juncea (UBCJI), U. brizantha and C. ensiformis (UBCEI), P. glaucum and C. juncea (PGCJI), P. glaucum and C. ensiformis (PGCEI), and spontaneous vegetation (SV). Cowpea was cultivated after desiccation of the cover crops. Most of the straw favored soil particle aggregation, except for C. juncea and SV, which negatively influenced this variable. Basal soil respiration, organic carbon content, potassium, base saturation, geometric mean diameter, macroaggregates, and macroporosity at layer of 0-0.10 m were the most sensitive indicators for improving soil quality in a savanna environment. UBS, UBCJI, and UBCEI were superior to the other treatments in improving soil quality. Almost all treatments increased cowpea yield by up to 29%, except for CJS and SV.

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ABSTRACT. Determining the number of replicates required to produce statistically testable results based on previously conducted tests is important to minimize labor costs via the use of existing information. The objective of this work was to determine the number of repetitions necessary to evaluate the characters of productivity and soluble solids in hybrids of two types of Inodorus melons. The study consisted of 20 experiments: 12 evaluated 10 hybrids of honeydew melons and 8 evaluated 13 hybrids of yellow melons. The experimental design consisted of randomized blocks with three replicates. Analysis of variance was performed to estimate the repeatability and genotypic determination coefficients. Variability in accurately predicting the genotype was observed for different number of repetitions between the evaluated characters and melon types. In the yellow melon, experiments with three repetitions allowed the accurate identification of superior genotypes with 81.1 and 61.9% certainty for productivity and soluble solids, respectively. In the honeydew melon, 62.4 and 71.2% accuracy was obtained for productivity and soluble solids, respectively.

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ABSTRACT. Popcorn (Zea mays L. everta) is a specialty crop with a higher aggregate economic value than that of common maize. In Brazil, national literature is still incipient and contradictory in terms of plant population management and water requirements. Furthermore, the interaction between these factors has not been reported, despite the increasing cultivation of popcorn. The objective of this trial was to determine whether agricultural traits and popping expansion from hybrid IAC 125 could be affected by plant density and levels of irrigation water, in addition to determining the significance level of the interaction between both factors. We investigated five plant populations (40,000, 55,000, 70,000, 85,000, and 100,000 plants ha-1) and five different levels of water depth in 2014/2015 [574.86 (without supplementary irrigation), 609.86, 644.86, 679.86 (control), and 714.86 mm] and 2015/2016 [857.4 (without supplementary irrigation), 867.26, 886.60, 916.78 (control), and 959.81 mm] using a complete block design with split-plot, comprising a main plot (for plant populations) and subplot (for water depth), with six replicates for each set. We found increasing linear effects from grain yield under population density and levels of water depth, but this interaction was not significant. Moreover, the popping expansion for the main effects and the interaction between plant populations and water depth, were not significant.

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ABSTRACT. Climate change and the expansion of agricultural lands to low-fertility soils have prompted studies on the effects of water and nutritional stress on nutrient uptake and use. This study aimed to evaluate the efficiency of absorption, translocation, and use of N in coffee cultivars under water stress (WS) and different N doses. The experiment was performed hydroponically and arranged in a 4 × 2 × 4 factorial randomized block design with three replications. These factors consisted of four coffee varieties, two N doses, and four levels of WS. At the end of the experiment, the dry matter production, N concentration, and N accumulation of plants, as well as nutritional efficiency indices were evaluated. The data were subjected to analysis of variance and regression. The results showed that in plants previously well-supplied with N, N stress induces greater allocation of dry matter in roots, mitigating the effects of subsequent water deficits on shoot dry matter production. Young Mundo Novo plants subjected to N stress followed by increasing water stress maintained a high utilization efficiency (UE). Young Acauã plants well-supplied with N, maintained their N utilization efficiency up to -1.6 MPa of water stress; however, when they were N starved, they underwent a drastic reduction in UE at potentials below -0.22 MPa.

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ABSTRACT. Most coffee (Coffea arabica) phytosanitary management techniques are performed using ground-based equipment, and remotely piloted aircraft are a recent alternative. Therefore, this study evaluates the effect of different application rates and hydraulic tips used for spreading phytosanitary products on coffee crops using a remotely piloted aircraft, assisted by artificial targets and dye tracing. The experiment was a 4 × 3 factorial randomized block design with four tips (XR 110-01, TT 110-01, AIXR 110-015, and TTJ60 110-02) and three application rates (8, 12, and 16 L ha-1). Hydrosensitive paper was used to analyze the droplet spectrum, and the Brilliant Blue tracer was used to detect spray deposition. The DJI Agras T20 remotely piloted aircraft was used to apply the phytosanitary product. Speed, flight height, and application range were maintained at 5.56 m s-1, 2 m, and 5 m, respectively. The flight direction was perpendicular to the crop planting lines. The application rate and hydraulic tip jointly controlled the accumulation of droplets on the target according to its position in the plant canopy. Therefore, remotely piloted aircraft can be used in coffee phytosanitary management, particularly to control targets that predominately occur in the upper third of the plant canopy.

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ABSTRACT. Combinations between crop intercropping and forage production in a no-tillage system are not well established for environments under low water retention and soil fertility conditions. Our study aimed to evaluate the potential interactions between soybean-grass intercropping with residual nitrogen in a no-tillage system. The experimental design was a randomized block with four replications in a subdivided plot scheme. The main plots in the summer season were: 1) soybean monoculture; 2) soybean - Aruana Guinea grass (Megathyrsus maximus cv. Aruana) intercropping, and 3) soybean - Congo grass (Urochloa ruziziensis cv. Comum) intercropping. The subplots were the nitrogen rates of 0, 50, 100, and 150 kg ha-1, applied as side-dressing in maize and grasses during the autumn-winter season. Here, the results of the summer seasons are shown. To do so, the parameters evaluated were soybean agronomic traits, dry biomass production, and macronutrient concentrations of plants intercropped. The main effects and interactions were studied. Our findings showed that soybean-Aruana Guinea grass intercropping is an alternative to no-tillage system implementation. Moreover, residual nitrogen from the autumn-winter season directly interfered with the dry biomass production of grasses intercropped with soybeans in the summer season. In short, the systems studied seem suitable for implementing a no-tillage system, which aims to neutralize degraded pastures and produce forage for ensilage. Despite the changes in macronutrient concentrations within the intercropping system and residual nitrogen, and among intercropped crops over the years, Congo grass intercropped with soybeans in the summer season showed great capacity for phosphorus, potassium, and magnesium cycling.

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ABSTRACT. Citrus represents one of the main fruit crops grown in the world, highlighting the ‘Tahiti’ acid lime tree. The objective was to compare rootstock varieties combined with this scion to identify those with the best agronomic performance and precocity of production, in addition to Phytophthora gummosis resistance. The experiment was carried out in Capitão Poço, northeast region of Pará, and the following seven rootstock genotypes were evaluated: ‘Sunki Tropical’, ‘BRS O S Passos’, ‘BRS Bravo’, ‘BRS Donadio’, ‘Citrandarin Indio’, ‘BRS Matta’, and ‘LVK x LCR-038’. A randomized block experimental design was used, with three replications and 10 plants per plot. The evaluated characteristics were: plant height (m); crown volume (m3); number of ripe fruit per plant; total yield of ripened fruit per plant (kg plant-1); cumulative fruit yield (fruit kg plant-1); and average productive efficiency (fruit kg m-3 of crown). The average productive efficiency was high. For early selection, the best rootstocks in terms of yield, stability and adaptability were Sunki Tropical, BRS O S Passos, and Cintradarin Indio. The fruit number had the greatest direct effect on fruit yield, and crown pruning was directly harmful. Further studies to understand the complex interaction of G x E for BRS Donadio and Sunki Tropical should be carried out.

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ABSTRACT. Macrospora leaf spot (MLS), caused by the fungus Stenocarpella macrospora, is one of the most important diseases affecting maize in Brazil. However, there are no MLS-resistant cultivars commercially available. Therefore, this study aimed to investigate the lesion expansion rate of MLS in four maize genotypes, leaf wetness duration (0-, 6-, 12-, 18-, 24-, 30-, 36-, 42-, and 54-hour post-inoculation), disease development severity in three maize genotypes, and resistance/tolerance levels to MLS in 141 maize genotypes commercially grown in Brazil. The estimates were performed using logistic models adjusted to the parameters analyzed, except for resistance/tolerance levels, which were analyzed using proposed severity and resistance scales. The experiment was carried out at the Laboratory of Plant Phytopathology of the Epagri/Cepaf, Santa Catarina State, Brazil, from 2016 to 2020. Disease resistance was significantly different among genotypes and fungal isolates. However, none of the genotypes showed resistance or high tolerance levels to MLS. Leaf wetness duration influenced maximum disease severity, and lesion expansion rate differed significantly among the genotypes tested. All information generated in this study is essential for breeding programs of maize for MLS resistance.

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ABSTRACT. Tomato is a demanding crop in terms of handling, mainly because irrigation has a strong influence on fruit production and quality. Salinity changes the absorption, transport, assimilation, and distribution of nutrients in the plant. In general, such effects are analyzed using statistical tests. However, fuzzy models allow simulations between points that are not verified in agricultural experimentation. Currently, systems with artificial intelligence have excelled in the field of applied sciences, particularly fuzzy systems applied to mathematical modeling. The objective of this research was to use fuzzy modeling to analyze the biometric variables during the development of hybrid tomatoes under two different conditions: the first concerning different water tensions in the soil and the second concerning different salinity doses in irrigation. To this end, two models were developed based on an experiment carried out at São Paulo State University (UNESP), School of Agriculture, Botucatu, São Paulo State, Brazil. Both models sought to estimate the values of biometric variables of the tomato crop. Thus, two models were developed: Model 1 regarded water tensions and days after sowing (DAS), while Model 2 featured salinity and DAS. Fuzzy models provided results that verified the effects of irrigation and salinity layers. Two Fuzzy Rule-Based Systems (FRBS), an input processor with two variables, a set of linguistic rules defined from statistical procedures with percentiles, the Mamdani fuzzy inference method, and the center of gravity method to defuzzification were elaborated for this purpose. The range between −25 and −10 kPa (for Model 1) and between 0.08 and 3 dS m−1 (for Model 2) provided the development within the ideal parameters for the complete development of the plant cycle. The use of fuzzy logic has shown effectiveness in evaluating the development of tomato crops, thus showing potential for use in agricultural sciences. Moreover, the created fuzzy models showed the same characteristics of the experiment, allowing their use as an automatic technique to estimate ideal parameters for the complete development of the plant cycle. The development of applications (software) that provide the results generated by the artificial intelligence models of the present study is the aim of future research.

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ABSTRACT. This study aimed to evaluate the effect of the summer pruning time in ‘Fuji’ apple trees on the quality of fruit at harvest and after storage in controlled atmosphere with extremely low O2 (CA-ELO) (0.5 kPa O2). The treatments evaluated were summer pruning in December, January, and February, in addition to a control treatment (without summer pruning). The experiment was carried out in the 2018/2019 and 2019/2020 growing seasons. The fruit were evaluated at harvest and after eight months of CA-ELO (0.5 kPa O2 + <0.5 kPa CO2/1.5 ± 0.2°C/92 ± 2% RH) storage, at chamber opening, and after 7 days of shelf-life at 23 ± 3°C and 60 ± 5% RH. The quality of the fruit was evaluated through of soluble solids, flesh firmness, titratable acidity, fruit color, and physiological disorder incidence (sunburn and flesh browning), in addition to enzymatic activity and concentration of functional compounds. There was no significant effect of the summer pruning time on fruit flesh firmness, soluble solids, titratable acidity, and rot incidence after storage under CA-ELO plus 7 days of shelf life. Summer pruning in February resulted in fruit with higher peel red color development, which in general contains a higher concentration of functional compounds at harvest (total phenolic compounds and total antioxidant activity), and lower flesh browning incidence in ‘Fuji’ apples stored under CA-ELO. The nitrogen (N) concentration and nitrogen/calcium ratio (N/Ca) in the second growing season were lower in fruit from plants pruned in February, compared to no summer pruning or earlier pruning. The superoxide dismutase and peroxidase enzyme activity were lower in fruit from treatments with summer pruning in January and February, whereas the polyphenol oxidase enzyme activity was lower when summer pruning was conducted in February.

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ABSTRACT. In soybeans, the integument or seed coat is an important modulator between the external and internal environment. It plays a fundamental role in seed vitality, and its lignin content may influence the seed quality. The objective of this experiment was to evaluate the quality of soybean seeds from a partial diallel and their reciprocals and its relationship with lignin content, seed coat thickness, and deposition location. The seeds were also evaluated for physiological quality through germination and accelerated aging tests. The lignin content was quantified by absorbance, and the integument thickness was analyzed and measured using scanning electron microscopy. The most contrasting cultivars for lignin content were analyzed using fluorescence microscopy and histochemical techniques. Cultivars and their reciprocals differed in seed physiological quality. We found differences in the genotypes for integument thickness. Using histochemical techniques, autofluorescence was observed in the same regions identified as lignified. Positive staining for lignin was observed in the hilum region. Among the genotypes, we found variations in the physiological quality of seeds (germination and accelerated aging test), lignin content, and integument thickness.

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ABSTRACT. To consider the different characteristics of soybean seeds for designing and regulating the post-harvest equipment, we evaluated the similarities in the physical properties of soybean cultivars in this study. Two-hundred soybean seeds from 40 genetically modified cultivars were collected in packages to measure the physical properties of the seeds. First, principal component analysis was performed to verify the interrelationships between the variables and soybean cultivars. Next, a boxplot was constructed for each variable, considering the groups obtained after analyzing the main components. Finally, a scatterplot containing the Pearson's correlations between the variables was constructed. We identified two clusters of cultivars: C1 and C2. The unit-specific mass was the physical property that contributed the most to the formation of C1, whereas the other physical properties contributed to the formation of C2. Soybean cultivars comprising C1 were similar to each other only in unit specific mass, and the cultivars allocated to group C2 were similar according to all the other properties evaluated. These results can serve as a guideline for genotype selection for soybean genetic improvement to minimize variations in the physical characteristics of the seeds and obtain greater efficiency in the processing stages. Thus, the equipment manufacturing industry and seed processing units can implement projects and equipment adjustments to manage the post-harvest and seeding processes of soybean seeds efficiently.

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ABSTRACT. The objective of this work was to study the biomass production and chemical composition of the different parts of the cassava plant during the first and second vegetative cycles, with the aim of providing data that can contribute to the understanding of the response of cassava cultivars to different harvest ages. The experimental design consisted of randomized blocks in split plot scheme. Plots were represented by cultivars IAC 90 and IAC 118-95 and subplots by crop age (2, 4, 6, 8, 10, 12, 14, 16, and 18 months after planting). Our results showed that the ‘IAC 90’ allocated a higher proportion of assimilates to the leaves, stem and planted cutting than the ‘IAC 118-95’, which was more efficient in allocating dry matter to the storage roots. Storage roots showed an increase of more than 50% in starch content 14 months after planting. The cultivar IAC 118-95 is distinguished by the higher harvest index, allowing earlier harvesting, with possible valorisation of the leaves as industrial raw material. Variables showed different degrees of inter-relationships amongst themselves. Total plant fresh matter and dry matter yields were positively correlated with growth parameters and root starch for both cultivars. Harvest time and cultivar are key factors that should be considered to increase profits in the cassava agro-industrial chain.

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ABSTRACT. Native to the Brazilian Atlantic Rainforest, cambuci fruits can be consumed either in natura or in the processed form, and cambuci trees can be used to recover degraded areas. However, studies regarding cambuci germination and seedling development are scarce. The main aim of this study was to understand how different substrates and containers influence the growth of cambuci seedlings. To this end, two experiments were conducted: five different substrates were tested in the first experiment, and based on the multivariate analysis of the first experiment, the effect of combination of the best-performing substrates and three commonly employed plant growth containers on seedling development was investigated. Overall, good quality cambuci seedlings were obtained when they were grown in the commercial pine bark substrate and peat and perlite mixture in a 260 cm3 container.

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ABSTRACT. This study aimed to carry out the extraction and chemical characterization of oil from crambe treated with resistance inducers during its cultivation to promote greater efficiency in the defense system of plants. For this purpose, Agromos® and Ecolife® inducers were applied at rates of 0.5 and 1.0 L hectare−1 during crambe cultivation. Crambe seed oil was obtained in a Soxhlet extractor using n-hexane as a solvent and the oils were characterized in terms of fatty acid composition and minority compound contents (phytosterol and tocopherol). The oil obtained from seeds without the application of inducers (control) was also characterized. We determine the oxidative stability of oils with inducer application that presented higher minority compound contents. Crambe seeds that received the treatment with the Agromos® resistance inducer had higher oil content. However, in general, the fatty acid profile of the obtained oils was similar and showed a predominance of erucic and oleic acids (which represent ~82% of the composition). The application of the Agromos® inducer allowed obtaining seeds that provided oil with higher contents of phytosterols and tocopherols and higher oxidative stability.

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ABSTRACT. Sunflower growth is adversely impacted by both excess and insufficient water. Research on root growth in this crop under water stress conditions remains limited and does not fully elucidate the plant's response to varying soil and climatic conditions. This study aimed to determine root growth, depth, and distribution of sunflower plants under different water stress conditions, such as deficit or excess, in two soil classes and sown during two distinct periods. Experiments were conducted after sowing at the beginning of September (first crop season) and at the beginning of January (second crop season) in an Ultisol (Santa Maria, Rio Grande do Sul State, Brazil) and an Oxisol (Panambi, Rio Grande do Sul State, Brazil). Water condition treatments applied from stage V6 included control, water deficit, and water excess. Roots were collected using an auger drill during the first crop season. The variables analyzed comprised root length density and accumulated root within the soil profile. During the second crop season, sunflower roots were visually assessed in the soil profile after trench excavation. Root system depth and root dry mass were evaluated during both sowing periods. Results indicated that sunflower root penetration is deeper in Ultisol than in Oxisol. Water deficit promotes root depth, while water excess promotes root growth near the surface. Sowing during the first crop season results in deeper root penetration and higher root dry mass production compared to the second crop season.

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ABSTRACT. Proper potassium (K) fertilization management is crucial for optimizing yield and minimizing environmental impacts in colored fiber cotton cultivars, particularly in semiarid regions. This study aimed to assess the efficiency of K use by colored cotton cultivars under K fertilization in a semiarid region. Two experiments were conducted in 2019 and 2021, representing two agricultural seasons. The experimental design employed randomized blocks with split plots and four replications. The main plots consisted of five randomized K doses (0, 60, 120, 180, and 240 kg ha-1 of K2O), while subplots included four cultivars of colored cotton (BRS Rubi, BRS Safira, BRS Topázio, and BRS Verde). The results revealed that BRS Rubi exhibited superior agronomic efficiency with a dose of 60 kg ha-1 of K2O in both agricultural seasons. The maximum efficiency of K use by colored cotton cultivars was achieved with a dose of 240 kg ha-1 of K2O in the semiarid region of Brazil. The cultivars BRS Rubi and BRS Topázio demonstrated the highest use efficiency. Furthermore, BRS Topázio displayed the highest K accumulation in plant shoots during both seasons.

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ABSTRACT. Agroforestry systems may show low CO2 efflux, and CO2 efflux contributes to sustainability. This work aimed to evaluate the soil CO2 efflux in coffee plantations cultivated in agroforestry and full-sun systems during the winter in high-altitude tropical climate regions. The work was carried out at three family farms (RO, GI, and PA) in Minas Gerais, Brazil. Two treatments were established: coffee with and without trees, and 20 sampling spots for soil and gases. The air and soil temperatures in the agroforestry systems were lower than in the full-sun systems. The soil moisture content in agroforestry systems was higher than full-sun only on the GI. Except for the agroforestry systems in PA, all the other systems showed an increase in CO2 efflux with increasing soil moisture. This increase was more pronounced in agroforestry systems (RO), followed by full sun (RO). On the GI farm, this correlation was lower in the agroforestry system. Soil CO2 efflux was positively correlated with soil temperature and negatively correlated with total nitrogen, labile carbon and total organic carbon. Therefore, despite the microclimate stability promoted by the agroforestry systems in the winter, no decrease in the soil CO2 efflux was observed when compared to full sun systems.

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ABSTRACT. Salt stress is a major abiotic factor limiting plant growth worldwide, particularly in arid and semiarid regions where excessive groundwater use in irrigation leads to high salt concentrations. To address this issue, this study investigated the efficacy of silicon, either alone or in combination with Trichoderma harzianum and organic matter, in mitigating salt stress in forage sorghum. The experiment took place in a saline Fluvisol in Parnamirim, a semiarid region of Pernambuco, Brazil, and followed a randomized block design with five treatments and four replicates: sorghum (control); sorghum + Si; sorghum + Si + OM (organic matter); sorghum + Si + T (T. harzianum); and sorghum + Si + T + OM. Sorghum plants were assessed over three cycles (initial cut and two regrowths) from June 2021 to April 2022. The combined treatments of Si + OM, Si + T, and Si + T + OM increased plant growth by 42.17, 35.49, and 27.51%, respectively, compared to the control. Similarly, these treatments led to biomass accumulation gains of 39.42, 40.44, and 31.77% in sorghum plants relative to the control. Silicon alone did not yield significant growth or biomass accumulation improvements. The application of silicon in conjunction with T. harzianum and/or organic matter shows promise in enhancing forage sorghum growth under saline stress conditions in semiarid regions.

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ABSTRACT. The furrow-ridge system was designed to allow the cultivation of dryland crop species in lowlands, enabling rotation with rice. After harvesting the dryland species, farmers usually return with rice in the following cropping season, with costs associated with dismantling ridges before sowing rice. The possibility of sowing rice directly on residual ridges should be investigated to avoid these costs. The objective was to verify the ecophysiological adaptability of rice sown on residual ridges from the previous dryland crop in lowlands, and to identify possible factors impacting the physiological performance of rice plants in this new production system. The experiment was installed in the field in a randomized block design with 5 treatments and 12 replications. The treatments considered the plant’s position in the field and in the irrigation furrow. The parameters of the growth analysis were calculated using the classical method. There was no significant damage to rice plants in any part of the field, and there was no difference between plants at the top or bottom of the furrow. Therefore, there is no need to dismantle residual ridges from previous dryland crops before planting rice in the succeeding cropping season in the lowlands of Rio Grande do Sul State, Brazil.

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ABSTRACT. For a banana tree to reach its productive potential, plants must be nutritionally balanced. Therefore, it is important to use methods that diagnose the nutritional status of plants through chemical leaf analysis, considering the relationships between nutrients and taking advantage of productivity and nutritional monitoring data from orchards. This study aimed to establish norms and ranges of nutrient sufficiency for ‘Nanica’ banana trees in Vale do Ribeira, São Paulo state, using the Diagnosis and Recommendation Integrated System (DRIS) method. Productivity data and chemical analysis of the leaf tissue of 291 commercial plots of Nanica banana trees, collected between 2015 and 2020 in Vale do Ribeira, were used. The DRIS method was used to establish norms and sufficiency ranges for N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn. Fruit yield did not correlate with the average nutritional balance index (NBIa), indicating that its variation was affected by non-nutritional factors. The contents of K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn showed high correlations with their respective nutritional indices. The sufficiency ranges and adequate nutrient contents differed from the values established for bananas in the literature.

Abstract in English:

ABSTRACT. It is common to observe conventional methods for estimating soybean crop yields, making the process slow and susceptible to human error. Therefore, the objective was to develop a model based on deep learning to estimate soybean yield using digital images obtained through a smartphone. To do this, the ability of the proposed model to correctly classify pods that have different numbers of grains, count the number of pods and grains, and then estimate the soybean crop yield was analyzed. As part of the study, two types of image acquisition were performed for the same plant. Image acquisition 1 (IA1) included capturing the images of the entire plant, pods, leaves, and branches. Image acquisition 2 (IA2) included capturing the images of the pods removed from the plant and deposited in a white container. In both acquisition methods, two soybean cultivars, TMG 7063 Ipro and TMG 7363 RR, were used. In total, combining samples from both cultivars, 495 images were captured, with each image corresponding to a sample (plant) obtained through methods AI1 and AI2. With these images, the total number of pods in the entire dataset was 46,385 pods. For the training and validation of the model, the data was divided into subsets of training, validation, and testing, representing, respectively, 80, 10, and 10% of the total dataset. In general, when using the data from IA2, the model presented errors of 7.50 and 5.32% for pods and grains, respectively. These values are considerably lower than when the model used the IA1 data, where it presented errors of 34.69 and 35.25% for pod and grain counts, respectively. Therefore, the data used from IA2 provide better results to the model.

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ABSTRACT. Strawberry cultivation possesses unique features, including the need for high-quality seedlings adapted to the cultivation environment and proper fertigation management. These elements influence plant growth and production. This study evaluated the growth and dry matter partitioning of strawberry plants of the cultivar "Albion" at different seedling ages (0, 14, 28... 196 DAT) using two fertigation methods: open-loop and closed-loop systems. Fifteen evaluations occurred throughout the cultivation cycle, spanning from planting to 196 days after transplanting (DAT), with the study replicated over two consecutive years. We evaluated dry matter partitioning among roots, stems, leaves, senescent leaves, flowers, commercial fruits, and non-commercial fruits. We also measured root volume and length, besides counts of leaves, flowers, and both commercial and non-commercial fruits. Despite no significant differences between fertigation systems for most variables, the closed-loop system shows promise, contingent on proper nutrient solution management. The partitioning analysis revealed that fruits, followed by leaves, were the primary consumers of photoassimilates.

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ABSTRACT. Rich in oil and protein, canola is a significantly promising crop and is widely explored as an alternative to grain cultivation in the winter period. Recently, canola oil has been largely consumed due to a variety of health benefits and low production costs. Nonetheless, impasses such as determining the correct sowing date and optimizing harvesting methods make it difficult to expand cultivation. Accordingly, the purpose of the study was to evaluate the performance of two canola hybrids on three sowing dates and distinct harvesting procedures. The study was conducted in Cachoeira do Sul, Rio Grande do Sul, Brazil, on three sowing dates (2019, 2020, and 2021), with two hybrids (Hyola 433 and Hyola 575 CL). The methods of direct harvesting, direct harvesting with the application of adjuvant, cut-row, and cut-row with the application of adjuvant were evaluated. The main yield components were determined, in addition to biochemical parameters, such as oil and protein content and determination of oil quality (acid, peroxide, iodine, extinction, and saponification indices). Appropriately, this study indicated that canola is significantly sensitive to climatic conditions, mainly to temperature and sowing time, reducing grain and biomass yield in late sowing and resulting in serious harvest losses. Oil and grain protein contents were affected by climatic conditions. Nevertheless, the protein content was not affected by late sowing. Canola oil presented significant chemical conditions, with a correlation between the crops with higher oil yield and better oil quality.

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ABSTRACT. Plant growth models, derived from reliable databases, enable development of software for recommending cultural practices, harvest predictions, and enhancing productivity. This study aimed to create, refine, and simulate reference models for pineapple growth and development, adapting them based on nitrogen supply per plant and plant density per hectare. We utilized a field test database with periodic assessments of root, stem, leaf, fruit, and stem diameter fresh and dry weight, along with climate data from meteorological stations in or near the experimental areas. These growth models were developed, considering significant correlations and high correlation coefficients, using both simple non-destructive (stem diameter) and destructive (fresh or dry weight of D leaf) plant evaluations, either separately or in combination. The resulting models can provide estimated predictions for pineapple growth, adaptable to varying plant populations and nitrogen fertilization rates (measured in grams of N per plant).

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ABSTRACT. This study aimed to evaluate the effect of silicon and acibenzolar-S-methyl sources on the development of yellow melon (Cucumis melo L.) in the field and the occurrence of diseases in different years. The treatments consisted ofthe silicon sources Agrosilício® (3 g L−1), Rocksil® (3 g L−1), and Chelal® Si (2 L 100 L−1), the additional treatments acibenzolar-S-methyl (ASM) (2 mM) and the fungicide thiabendazole (400 mL 100 L−1), and a control (sterile distilled water). The following characteristics were evaluated: natural incidence of diseases; gas exchange: CO2 assimilation rate, transpiration, stomatal conductance, internal CO2 concentration, water use efficiency, instantaneous water use efficiency, and carboxylation; postharvest aspects: fruit weight, pulp thickness, pulp firmness, titratable acidity, pH, soluble solids, and vitamin C content; productivity; and the enzymatic activity of peroxidases, polyphenol oxidases, and phenylalanine ammonia-lyase. No significant response was observed for naturally occurring diseases. Treatments with Chelal®Si, Rocksil®, and Thiabendazole® increased photosynthetic and transpiration rates in the yellow melon. The silicon and ASM sources did not influence the physicochemical characteristics or the enzymatic activity of fruits. No effect was observed on the biometric characteristics, productivity, and chemical quality of fruits in both years of cultivation. Si sources increased photosynthetic rate and transpiration. However, no diseases were observed during the experimental period. Leaf spraying with silicon and acibenzolar-S-methyl sources did not influence the biometric characteristics and fruit production of yellow melon. The silicon and acibenzolar-S-methyl sources did not induce an increase in the enzymatic activity of peroxidases, polyphenol oxidase, and phenylalanine ammonia-lyase. Fruit production was higher in 2020.

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ABSTRACT. This study investigates the meteorological variables exerting the most significant influence on the growth and productivity of four tomato hybrids cultivated for industrial processing in the Brazilian Savannah of Goiás State. Data on morphological and meteorological variables were collected in five locations (Hidrolândia, Itaberaí, Palmeiras de Goiás, Piracanjuba, and Silvânia) during the year 2020. Morphological characteristics assessed included plant height, number of branches, and leaf area index (LAI). Meteorological variables considered were average air temperature, global solar irradiance, thermal sum, and soil water availability. Pearson correlations, canonical correlations, and multivariate Stepwise regression were employed to analyze the relationships between morphological and meteorological variables. The study revealed that soil water availability significantly impacts tomato crop development, indicating the need for improved irrigation management. Adequate irrigation management contributed to an 86.1% increase in plant height and a 79.7% boost in leaf area index, while average air temperature influenced a 34% increase in the number of branches. In conclusion, proper irrigation management is crucial for enhancing tomato crop growth and development and optimizing water use.

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ABSTRACT. Garlic cultivation holds significant importance in Brazil. However, research on garlic crops is currently limited and outdated, highlighting the necessity for new studies, particularly focused on enhancing weed management and optimizing the use of agricultural inputs. This study aimed to assess the extent of yield losses attributed to weed interference and the specific periods during which weed interference impacts garlic crop yields in the state of Santa Catarina, Brazil. The experiments were conducted in Curitibanos, Santa Catarina State, Brazil, during 2019 and 2020, using the garlic cultivars Chonan and Ito, respectively. A randomized block experimental design was employed, consisting of 16 treatment groups with four replications. The design incorporated a 2×8 factorial arrangement, involving two weed management strategies (coexistence and control) and eight crop-weed coexistence periods (0, 15, 30, 45, 60, 90, 120, and 130 days after crop emergence - DAE). The study evaluated the weed community and recorded data on the number of bulbs, bulb diameter, as well as total and commercial bulb yields of garlic crops. The results indicated average losses of 24.3% in total bulb yield and 28.9% in commercial bulb yield. Critical periods for effective weed control were identified as 6 to 126 DAE in 2019, 5 to 126 DAE in 2020 for total yield, 3 to 126 DAE in 2019, and 5 to 126 DAE in 2020 for commercial bulb yield. Consequently, it is imperative to maintain garlic crops weed-free throughout most of their growth cycle.

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ABSTRACT. The grain production area in the Brazilian agricultural region known as SEALBA, especially in Alagoas State, has seen significant growth in recent years. This study aims to contribute to sustainable regional development by evaluating the effects of inoculation, co-inoculation, and the application of starter mineral nitrogen (N), either individually or in combination, on soybean growth and yield. Eight field experiments were conducted from 2018 to 2021 in two municipalities within Alagoas, covering soybean cultivation areas ranging from the first to the fourth year. The experiments followed a randomized complete block design with four replications, employing a factorial arrangement of treatments. The first factor encompassed five levels related to inoculation technologies and N management: 1) Inoculation with Bradyrhizobium; 2) Inoculation with Bradyrhizobium combined with N basal fertilization; 3) Co-inoculation of Bradyrhizobium + Azospirillum; 4) Co-inoculation of Bradyrhizobium + Azospirillum + N fertilization at the base; and 5) Control treatment without microbiological inputs or nitrogen fertilizers. The second factor involved the evaluation of different soybean cultivars, with two materials assessed in 2018 and three cultivars in 2019, 2020, and 2021. Results demonstrated that seed inoculation with Bradyrhizobium led to increased soybean grain yield in first-year cultivation areas. However, N basal fertilization, commonly known as starter fertilization, did not result in yield improvements compared to the use of microbiological inputs alone. Soybean cultivars BRS 9383 IPRO and FTR 3191 IPRO exhibited greater responsiveness to seed inoculation with Bradyrhizobium.

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ABSTRACT. Management systems that include trees tend to provide higher amounts of plant biomass to the soil, contributing to the increase in carbon (C) and nitrogen (N) stocks. This study simulated C and N stocks and their compartments in a crop-livestock-forest integration system in the edafoclimatic conditions of the Maranhão Cerrado using the Century 4.5 model. The evaluated areas were native Cerrado vegetation (NV) and crop-livestock-forest integration (CLFI). The calibration process gradually modified the model parameters to better fit the simulated and observed soil C and N stocks. The best fit between the data was obtained after changes in the main parameters (DEC3(2), DEC4, and DEC5) that controlled the rate of decomposition of soil organic matter. C and N stocks increased by 14% and 15%, respectively, over 14 years after replacing NV with CLFI. The slow compartment of C presented greater sensitivity to changes in management, with an increase of 47% compared with that of NV. The active compartment increased by 31% and the passive compartment remained constant for over 14 years. Future scenarios, where pasture was maintained between the eucalyptus trees and the scenario that allowed the soybean, corn, and Brachiaria rotation between the trees, were more effective, accumulating approximately 37 Mg C ha-1. The continuous contribution of residues from the trees and pasture increased C and N stocks in the long-term in the slow fraction, where the total organic carbon increased from 32 to 36 Mg ha-1 when NV was replaced with CLFI. The model predicted the C and N stocks with accuracies ranging from 1 to 11% of the observed values.

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ABSTRACT. Brazil has high soil loss rates due to its tropical and subtropical climate characteristics. In this sense, soil use and management practices may minimize such losses. In this study, experimental plots were monitored for eight years in southern Brazil during natural rainfall events. Treatments were as follows: I) bare soil under conventional tillage, II) barley-oat/ soybeans succession under conventional tillage, III) oat-lupine-vetch/ maize succession under conventional tillage, IV) barley-oat/ soybeans succession under no-tillage, and V) oat-lupine-vetch/ maize succession under no-tillage. Data on rainfall amount and erosivity indices (EI30, EI20, and EI10) were subjected to regression analyses, evaluating the effects of climatic variables on soil and water losses. We could also analyze crop species, conventional and no-tillage systems, and winter and summer seasons. The highest soil and water losses occurred in treatments under conventional tillage. In addition, soybeans treatments increased soil and water losses. Maize under no-tillage was the most efficient practice, as it had soil losses (3.4 times) and water losses (1.5 times) lower than soybeans under conventional tillage. Rainfall amounts and EI30 were better correlated with soil and water losses in conventional tillage treatments. However, EI10 could better explain the soil losses from the conservationist treatment.

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ABSTRACT. Integrated agricultural production systems can increase soil organic carbon stocks over time and contribute to the mitigation of climate change. The present study aimed to evaluate soil carbon stocks, accumulation rates (TOC), total nitrogen (TN), and the quality of soil organic matter (SOM) after the transition of a low-productivity pasture into agrosilvopastoral systems in the Cerrado biome. We evaluated an 11-year-old experiment, and the treatments studied were: Eucalyptus + buffel grass; Eucalyptus + cowpea; Eucalyptus + pigeon pea; eucalyptus + buffel grass + cowpea; Eucalyptus + buffel grass + pigeon pea; Eucalyptus in monoculture (with a 20 × 3 m tree arrangement and no cultivation between rows but with a history of forage and grain crop production); and a low-productivity pasture as additional treatment and reference to the soil condition previously the land-use change. In this study, TOC and TN stocks and accumulation, labile (LC) and non-labile carbon (NLC), and SOM humic fractions were evaluated at 0-10, 10-20, 20-40, and 0-40 cm depth layers. Integrated farming systems have increased TOC and TN, NLC, carbon contents and stocks in SOM chemical fractions in all depths and TOC and TN accumulation of 5.22 Mg ha-1 year-1 and 0.23 Mg ha-1 year-1, respectively, at the 0-40 cm depth layer. The integration of Eucalyptus with legumes or buffel grass increased the LC content in the surface layer of the soil. The transition from low-productivity pasture into integrated farming systems can promote the recovery of SOM and soil quality. Hence, our results suggest that agrosilvopastoral systems can be used as sustainable farming systems in the Cerrado biome.