Resumo em Inglês:

ABSTRACT Planting is considered one of the most essential steps in coffee growing. Lack of uniformity in planting may compromise future operations. Therefore, verifying planting operations quality is fundamental to optimizing production processes and reducing costs. This study aimed to investigate planting techniques through Statistical Process Control (SPC) and aerial images. Carried out in two areas, managed manually and semi-mechanized in the Bom Jardim Farm (MG - Brazil). Data were collected through Remotely Piloted Aircraft (RPA). Quality control charts and density maps were used to identify variations in distribution and spacing between plants and planting rows. It was found that the planting carried out manually was 4.7% wider than projected due to spacing reduction from 0.5 m to 0.48 m. The semi-mechanized system displayed a deficit of 7% compared to the projected planting system, using 0.55 m between plants. The density map showed the most significant planting alignment variations. Despite displaying lower results than the manual system, the semi-mechanized system improvements are valid for their minimal average variations. Thus, correcting points found outside the limits can increase the efficiency of semi-mechanized planting.

Resumo em Inglês:

ABSTRACT Currently with a more demanding market, is necessary to produce better and high physiological quality cultivars of soybeans. In front of this new challenge, our objective was to evaluate the physiological quality of 11 soybean cultivars: CD201, SYN1263, SYN1279, BMX, UFLA1, CA115, CD215, CD202, Conquista, Savana, and BRS820 storage for 12 months. Evaluations were conducted through physiological like germination and vigor (accelerated aging and controlled deterioration) and isoenzymes analysis. The seeds were stored under controlled conditions at 10 °C and 10% relative humidity. It was assessed every four months (0, 4, 8, and 12). 200 seeds per treatment were used for each test, divided into 4 replications of 50 seeds. The number of normal plants was evaluated on the fifth and seventh days, expressed as a percentage value. Isoenzyme analysis of MDH, ADH, Esterase, and Catalase was made. The results were interpreted from the presence or absence of bands in the gel. An experimental design in randomized complete blocks, interpreting data using analysis of variance in a factorial scheme 11 x 4 (11 cultivars and 4 times of storage and averages compared by the test Scott-Knott 5% of probability and regression analysis. The statistical program used was Sisvar®. We found that cultivars Savana and Conquista showed low physiological quality, and the cultivars CD 215 and BMX showed high physiological quality during storage.

Resumo em Inglês:

ABSTRACT The cowpea is a legume that is widely grown in the north-east of Brazil, and which has been gaining ground in other regions of the country. The main producer is the state of Ceará, with a large planted-area, albeit low productivity due to a lack of producer technology and adapted cultivars. The aim of this study was to identify and recommend superior genotypes in terms of adaptability and stability under rainfed and irrigated conditions, in addition to genotypes with reduced grain darkening. To this end, six experiments were conducted in different districts of Ceará (Crato, Pentecoste, Crateús, Madalena, Bela Cruz and Limoeiro do Norte) and one laboratory experiment, to evaluate grain darkening. The experimental design of the field trials was of randomised blocks, with 14 genotypes and 4 replications. The analysis of variance showed a significant effect from the genotypes and environments and their interaction, so GGE Biplot analysis was carried out to evaluate adaptability and stability. To evaluate grain darkening, a completely randomised design was used in a simple factorial scheme with six previously selected genotypes and five different storage times (0, 2, 4, 6 and 8 months). There was a significant effect from the genotypes and storage time. Genotype 1 showed the least darkening, and can be recommended for environments to which it is best adapted (Crato and Crateús). Genotype 9 was considered the most stable for grain yield, and can be more broadly recommended for the semi-arid region of the state of Ceará.

Resumo em Inglês:

ABSTRACT Biochar can promote crop production and soil quality. However, its characteristics depend on the waste used in its production and its effects may vary according to the species being cultivated and the management adopted. The aim of this study was to evaluate the application of biochar from animal waste on soil quality and the agronomic characteristics of the cowpea. An experiment was set up to test three types of biochar (bovine-BB, swine-SB and poultry-BP), with added fertiliser (BBF, SBF and BPF) and two control treatments, including the addition of calcium magnesium oxide (CT) and calcium magnesium oxide with fertiliser (CTF), giving a total of eight treatments with four replications. There was a respective increase of up to 102.94%, 1048%, 1560% and 360.22% in stem diameter, number of pods, number of grains per pod and stem dry matter from adding the biochar. The poultry biochar increased each of the above parameters even with no added fertiliser. There was no difference in basal soil respiration or β-glucosidase enzyme activity, whereas organic carbon (TOC), total nitrogen (TN), microbial carbon and soil labile carbon were greater with biochar. BBF gave the highest TOC content (24.40 g kg-1), while BP and BPF increased TN by around 61%. The application of biochar + fertiliser contributed to an average reduction of 56% in the soil metabolic quotient. Poultry biochar favoured both the agronomic characteristics of the cowpea and soil quality, while bovine biochar showed more marked results with the addition of fertiliser.

Resumo em Inglês:

ABSTRACT Moringa oleifera Lam. is an arboreal forest species of great economic potential, adapted to the climatic conditions of the Brazilian semi-arid region, whose multiplication is mainly by seeds. Rapid viability and vigor tests help in the choice of lots. Thus, the objective of this study was to assess the efficiency of the pH of exudate and primary root protrusion tests in the evaluation of viability and vigor, respectively. Two seed lots were initially evaluated for moisture content, germination, first count, germination speed index, seedling length, seedling dry mass and electrical conductivity. For the pH of exudate test, phenolphthalein (1%) and sodium carbonate (2 and 4 g L-1) solutions were prepared, with three soaking periods (1, 3 and 5 h) and three temperatures (25, 30 and 35 °C). Exudate solution in strong to light pink color indicated viable seeds, whereas very light pink color to colorless indicated non-viable seeds. The primary root protrusion test was performed under 25, 30 and 35 °C, evaluating the primary root protrusion of at least 2 mm, every 12 h until 196 h. The experimental design was completely randomized, with four replicates. pH of exudate test with 1 h of soaking at 25 or 30 °C with 2 g L-1 sodium carbonate solution was promising, but further studies are needed before it is indicated as routine use for the species. Primary root protrusion test is efficient and can be conducted at 35 °C with evaluation after 48 h.

Resumo em Inglês:

ABSTRACT The development of aquaculture through the cultivation of what are considered unconventional species is an option with the potential to solve the problem of food scarcity. The aim of the present study was to evaluate the zootechnical performance of juvenile Pomacea haustrum fed different commercial diets, and subjected to different levels of salinity. After seven P. haustrum spawn had hatched in the laboratory, the juveniles were randomly selected and transferred to the rearing containers. Two different commercial diets were offered: rabbit feed with a high proportion of ingredients rich in crude vegetable protein (VP), and dog food containing balanced levels of ingredients rich in crude vegetable and animal protein (MP). The selected juveniles were randomly stocked at different salinities (0, 2 and 4 parts per thousand - ppt). The experiment lasted 65 days. Twenty-one hours after the start of the experiment, 100% of the individuals reared at a salinity of 4 ppt had died. There was a significant difference (p ≤ 0.05) between the results for zootechnical performance (average final weight, weight gain, average final growth, specific growth rate, protein efficiency and apparent feed conversion) for animals reared in fresh water or at a salinity of 2 ppt, regardless of the type of diet. The origin of the protein in the diet had no significant effect on the zootechnical performance of the individuals; however, the salinity of the water impaired development of the animals in direct proportion to its concentration.

Resumo em Inglês:

ABSTRACT Desertification is the degradation process caused by climatic conditions and human activities that results in loss of soil productivity and decline in vegetation growth in the long term. Several indices related to vegetation, soil and climate are used to monitor desertification, but few studies explore qualitative and quantitative aspects of indices on desertification on spatial and hierarchical scale. This study aims to identify and measure indices related to increased risk of desertification on global, local and hierarchical scales using multinomial logistic regression models. Images from TM, ETM+ and OLI sensor from 1997 to 2018 in the end of dry and rainy seasons were used to quantify NDVI, TGSI, albedo, temperature, aridity index, evapotranspiration and precipitation on global spatial scale (Irauçuba Centro Norte) and local spatial scale (Miraíma, Canindé, Irauçuba and Santa Quitéria). GISD was calculated by geometric mean of weighted indices and segmented into 8 classes of susceptibility to desertification (hierarchical scale). The results showed that the best models were obtained on local scale and for the end of the rainy season. Temperature proved to be the most important variable for increased risk of desertification on global, local and hierarchical scales. Therefore, the increase in the risk of desertification in the studied areas is due to human activities of deforestation, overgrazing and fire. These factors contributed to reduction of vegetation cover and increase in temperature, changing the microclimatic, which led to decline in precipitation and worsening of desertification.

Resumo em Inglês:

ABSTRACT The correct use of tyres on agricultural tractors, in respect of the terrain and the type and internal pressure of the tyre, are factors that influence the performance of the tractor. The aim of the present study was to evaluate the operating performance of an agricultural tractor fitted with two types of traction device (radial and diagonal tyres) at different pressures, and operating on soil with two levels of moisture. The experiment was conducted on a dystrophic Red Yellow Argisol, with tests to evaluate the performance of the tyres under specific working conditions. Tractive power and tractive force, wheel slip and fuel consumption were evaluated. For each of the conditions under evaluation, the radial configuration showed better performance than the diagonal configuration, the effect being more significant at the lower pressure and under low soil moisture. The use of radial tyres led to an increase in traction capacity and drawbar power, with a reduction in fuel consumption, especially at higher slip rates.

Resumo em Inglês:

ABSTRACT Deformation intensity analysis for mechanical parts are very important data for machine design. For farm machines, these parameters present difficulties for determination due to its particularities. The Machinery industry searches for advanced technologies to determine the mechanical behavior of parts. This article shows the analysis of the reliability in the application of the laser triangulation technique (LTT) to determine the deformation of the mechanical elements of farm machines. A flat cutting disc with standardized dimension was selected as the object of study, as it is commonly used in farm machines, exhibiting a simple geometry made of steel, making the analysis procedure easier both for experimental execution and for data validation. Displacements of 1.0 mm to 10 mm were applied on the specimen. The theoretical behavior of specimen displacement was defined by finite element modelling with same condition of loading and dimension to compare the generated data by the experimental tests. Results indicated a displacement with maximum variation of 2.56% between experimental data and theoretical results and were considered satisfactory. LTT was able to determine deformation curve behavior of machine elements. It was concluded that Laser Triangulation Technique (LTT) was satisfactory to determine the deformation of a specimen.

Resumo em Inglês:

ABSTRACT The characterisation and evaluation of accessions are important steps in both the management of a germplasm collection and in a plant genetic improvement program. Carrying out characterisation and evaluation, whether morphological or molecular, requires observing the overall features of plants in the field, or collecting leaves for DNA extraction, which is time consuming and costly; whereas DNA extracted directly from the seeds allows access to the genome without the need for planting the seeds, which speeds up the selection of genotypes of interest and information on genetic variability. The aim was to develop a non-destructive method for extracting DNA from cashew seeds. The seeds were mechanically perforated using a mini-grinder, and a sample of the endosperm was removed. Various protocols and commercial kits for DNA extraction were tested, as well as materials to seal the opening made in the seed. It is possible to extract cashew tree DNA from the endosperm, preferably using commercial kits with cementitious adhesive as the sealing material, offering a germination percentage of 60% of the perforated seeds.

Resumo em Inglês:

ABSTRACT Cobalt (Co) and molybdenum (Mo) are essential elements with a fundamental role in biological nitrogen fixation in legumes. Vitamins such as thiamine, despite being required in small quantities, influence plant growth. This study aimed to assess the efficiency of different doses of thiamine applied as seed treatment, combined or not with Co and Mo, in enhancing the development of soybean crops. The experiment was conducted in a greenhouse according to a randomized block design with a 6 × 2 factorial arrangement, comprising six thiamine doses (0, 10, 25, 50, 100, and 200 mg kg-1) in the presence or absence of Co and Mo at the recommended rate of 100 mL ha-1. At 40 days after sowing, plants were analyzed for root length, root dry weight, shoot length, shoot dry weight, nodule number, and nodule dry weight. Principal component analysis showed that combined application of Co and Mo with thiamine was negatively associated with all variables and that the thiamine doses most positively associated with the analyzed variables were 50 and 200 mg kg-1. In treatments containing thiamine alone, there was a linear direct relationship between thiamine dose and nodule dry weight. Root and shoot lengths and dry weights were highest in plants treated with thiamine only at a dose of 122 mg kg-1. Application of Co and Mo combined with thiamine via seed treatment does not promote the development of soybean crops. Thiamine application is a promising treatment to increase shoot length, root dry weight, and nodule dry weight in soybean.

Resumo em Inglês:

ABSTRACT There is great interest in varieties with greater competitive ability against weeds. This can be facilitated by path analysis, which involves the statistical evaluation and interpretation of the relationship between yield and its components. In this analysis, the occurrence of multicollinearity results in inconsistent estimates of the coefficients, and overestimates of the direct effects of the explanatory variables on the response variable. The aim of this study was to identify the characteristics with the greatest direct effect on pod yield and green and dry bean yields in traditional cowpea varieties, evaluated in competition with weeds in two experiments. In addition, the presence of multicollinearity was investigated in the analyses. In Experiment-1, twelve varieties with the highest bean yields in a preliminary evaluation were assessed in a randomized block design with five replications. In Experiment-2, six varieties, selected in the preliminary evaluation, were assessed using two methods of weed management: three of the most productive and three of the least productive. Randomized blocks and split plots were used, with five replications. Multicollinearity, indicated by the number of conditions and the variance inflation values, was greater in Experiment-2. In the six cases under study (three yields x two experiments), the number of pods per plant had the greatest direct effect on yield.

Resumo em Inglês:

ABSTRACT Given the large differences in the results of inoculation and co-inoculation in the bean crop, an experiment in cultivating winter beans was carried out in 2019 under greenhouse conditions with the aim of evaluating the performance of the beans and a possible increase in plant growth and grain production, using seeds inoculated or co-inoculated with Rhizobium tropici and Azospirillum brasilense, with and without fungicide and/or insecticide, in sandy and clayey soils. A total of 112 pots were used, and 14 treatments were applied in a completely randomised experimental design, with four replications. The Scott-Knott test was used to analyse the results, and showed that whether using untreated seeds or carrying out complete chemical treatment with fungicide and insecticide plus co-inoculation with R. tropici and A. brasilense, winter bean production was reduced in clayey soil, while the joint use of fungicide and insecticide, fungicide and R. tropici, or fungicide, insecticide and R. tropici, favoured shoot development. Inoculating with A. brasilense, without R. tropici and with insecticide, or insecticide and fungicide, favoured greater root growth in clayey soil. In sandy soil, grain production was higher using seeds treated solely with insecticide, solely with R. tropici, or with a combination of both. Production was lower in the joint treatment with fungicide, insecticide and the co-inoculation of bacteria, or when using insecticide together with A. brasilense.

Resumo em Inglês:

ABSTRACT Due to the importance of grain production, and the need to work the soil under limited moisture, the aim of this study was to develop computer software to predict the tractive capacity of wheeled tractors for two types of tyre, the effect of different inflation pressures and levels of soil moisture. A mathematical model was developed to predict the tractive capacity of a 4 x 2 AFT tractor. Software was developed and tested by comparing the computational data with those from tests of a working tractor in the field. The parameters under evaluation were drawbar force and front and rear drive wheel slip. At both moisture levels, the bias tyres had the lowest front to rear slip ratio at the lower pressure; the ratios were similar when equipped with radial tyres. The bias tyres show maximum force at a slip ratio of 1.09 at the higher pressure and 1.03 at the lower, while for the radial tyres the ratio was 1.05 at the higher pressure and 1.07 at the lower. Software was developed to process data from the model, with the results used for estimating the tractive force of the tractor. The tractive force was overestimated by the model, which needs further adjustment for direct application in the field.

Resumo em Inglês:

ABSTRACT The estimation of evapotranspiration (ET) and crop water requirements are crucial for the proper management and allocation of water resources in terms of quantity, quality, and timeliness. Therefore, remote sensing estimation of ET using the SEBAL algorithm (Surface Energy Balance Algorithm for Land) can provide spatio-temporal, non-punctual data, unlike traditional calculations relying on the nearest meteorological station. This research analyzed ET using SEBAL, based on ten Landsat 8 satellite images processed with a program developed in the Model Builder of ArcGis® version 10.2. The analysis was conducted during the vegetative period of starchy corn from May to October 2016. Validation of the results happened with a drainage lysimeter installed in a monitoring plot. Additionally, the statistical indices - such as percentage relative error (PRE) (0,09), root mean square error (RMSE) (0,30), R2 (0,92), and Nash-Sutcliffe efficiency (NASH) (0,91) - indicated a good correlation of ET for starchy corn in the central highlands of Peru. The ET identified at ten monitoring points ranged from 1,05 to 7,79 mm d-1.

Resumo em Inglês:

ABSTRACT Exposing seeds to agents that elicit tolerance to abiotic stress, such as phytohormones and organic acids, during hydration and dehydration cycles can determine their response to later stimuli, e.g. exposure to salt stress. The aim of this study was to evaluate the action of priming cycles with different eliciting agents of salt stress tolerance on seeds of the cowpea varieties Sempre Verde and Pingo de Ouro. The seeds were subjected to the following treatments: 0.0 mM NaCl (control); 100 mM NaCl (salt stress); salt stress + three seed-priming cycles (PC) in water; salt stress + PC in gibberellic acid; salt stress + PC in hydrogen peroxide; salt stress + PC in salicylic acid; salt stress + PC in ascorbic acid. The following variables were analysed: germination, growth, dry weight, salt tolerance index, total soluble sugars, total free amino acids and proline. Salt stress (100 mM NaCl) reduced germination, length and biomass accumulation in the Sempre Verde and Pingo de Ouro varieties. These showed the best response to the priming cycles with gibberellic and salicylic acids, which promoted greater germination potential, length and biomass under a salt stress of 100 mM NaCl, affording greater tolerance via osmotic regulation, especially in the Sempre Verde variety.

Resumo em Inglês:

ABSTRACT Chia (Salvia hispanica L.) seeds have attracted great economic interest for their high levels of linoleic and α-linolenic acids. In Brazil, there is a lack of studies on the agronomic characteristics and physiological quality of chia, necessitating research on germination processes and strategies to enhance yield under field conditions. There are no studies assessing the development of seeds with different coat colors in the presence of fungicides. This study aimed to assess the physiological quality of chia seeds as a function of coat color and fungicide treatment. The experiment followed a completely randomized design with a 2 × 2 factorial arrangement and six replications. For this, seeds were divided into two groups according to coat color (black and white) and subjected or not to treatment with carboxin + thiram. Germination speed index, germination rate, and shoot length were evaluated in plants sown at 0, 90, and 180 days after seed treatment. Germination rate and speed index differed significantly between coat colors, with white seeds having higher vigor than black seeds. Shoot length, however, differed only for seeds sown on the day of treatment, indicating that treated seeds were more vigorous.

Resumo em Inglês:

ABSTRACT Proper waste management is a major worldwide concern; waste is disposed of directly into the environment, affecting water, soil and air quality. The development and production of green energy sources is strongly encouraged in modern society. The aim of this study, in accordance with Sustainable Development Goals (SDGs) 1, 2 and 7 of the 2030 Agenda of the UN, is to combine the correct disposal of animal waste with the generation of energy to mitigate the energy insecurity of families in an extremely vulnerable semi-arid region in the north-east of the country using biodigesters. To this end, a conceptual proposal was drawn up for a low-cost, easy-to-maintain and easy-to-use biodigester. A small-scale prototype was used to assess its operation by evaluating the main factors that affect biogas production (pH, temperature and the biomass properties: total solids, fixed solids, volatile solids, concentration of volatile fatty acids and C/N ratio). Evaluation of the test prototype gave satisfactory results that corroborate other studies and make it possible to propose an economically viable and efficient full-scale biodigester for biogas production.

Resumo em Inglês:

ABSTRACT The aim of this study was to verify the response of the melon accessions MR1 and C14 to gamma radiation in terms of germination and morphology.The melon accessions came from the germplasm collection of the Federal Rural University of the Semi-arid Region, and were submitted to five doses of gamma radiation (0, 100, 200, 300, 400 Gy) in four replications, each comprising 25 seeds, at the Center for Nuclear Energy in Agriculture of the University of São Paulo. The seeds were grown in a greenhouse at UFERSA employing a completely randomised design. The germination potential, rate and index were evaluated during the first stage of the trial. During the second stage, the germinated plants were transplanted into eight-litre buckets containing substrate and sand, in four replications of 15 plants each. The inflorescence, leaf blade and fruit were evaluated. The IMAGE J image analysis software was used to obtain the leaf and fruit data. The germination potential varied for the gamma-ray doses being tested, while the germination rate and index were not affected; phenotypic variations were seen in the leaves. The gamma-ray doses had no effect on the germination process.

Resumo em Inglês:

ABSTRACT The aim of this study was to characterise the lignocellulosic fractions of pruning waste from tree species showing potential for furniture production in Acaraú, Ceará. The experiment was conducted in a completely randomised, split-plot design, with the plots corresponding to two water regimes (irrigated for one year and irrigated for three years) and the sub-plots to eight tree species, with three replications. The chemical attributes were determined after seven years. Except for the insoluble lignin content, there was a significant effect from the different species in terms of the chemical properties of the wood. The results for the lignocellulosic fractions show the possibility of developing technological ways of adding value to these waste products, especially considering their lignin content. The different species also showed potential for use in producing cellulose pulp, with the exception of Handroanthus impetiginosus due to its high ash content. The results of this study offer new perspectives for future research into the use of forestry waste.

Resumo em Inglês:

ABSTRACT The search for more sustainable systems of rice cultivation, especially in relation to water use, has included the evaluation of more-efficient irrigation systems in addition to alternative water sources. The aim of this study was to conduct a phytosociological survey of weeds in rice crops irrigated by subsurface drip with different concentrations of treated dairy effluent, maintaining the soil moisture at saturation or field capacity. A pilot scale experiment was carried out in a protected environment using a randomised block design in a 5 x 2 factorial scheme, with four replications. The IAC 301 cultivar (Arborio rice) was chosen. The phytosociological surveys were carried out on four different dates, and considered the composition as well as the distribution of plant species in each of the applied treatments, using the importance value index (IVI) to evaluate the influence of each treatment. The results showed that cultivating irrigated rice, giving priority to water management, altered the ecology of invasive plants. Fourteen weed species were identified, distributed over 10 families. The effluent dose did not alter the incidence of invasive plants, and only at the final evaluation was there a reduction in the IVI value at effluent concentrations of 50% and 75%. For soil moisture, the highest IVI values occurred on the first two days of the survey under saturated conditions; this result was reversed closer to plant maturity, when the IVI values were higher at field capacity.

Resumo em Inglês:

ABSTRACT The physiological quality of soya bean seeds is a determining factor in establishing the crop in the field. The aim of the present study was to evaluate the physiological quality of soya bean seeds produced by plants grown from seeds of different sizes in two crop seasons. The BS 2606 SOYTECH, NS 6700 IPRO, NA 5909 RR, BS IRGA 1642 IPRO and LANÇA 58i60 IPRO cultivars were used, sown in 2019/2020 and 2020/2021. The experimental design was of randomised blocks, with treatments comprising seeds from plants grown from seeds of three sieve sizes (5.5, 6.0 and 6.5 mm for cultivars BS2606, NS 6700 IPRO, NA 5909 RR, LANÇA; and 6.0, 6.5 and 7.0 mm for the BS IRGA 1642 IPRO cultivar). The following tests were conducted: germination, first germination count, shoot and root length, total seedling dry weight, seedling emergence, accelerated ageing and electrical conductivity. The results were subjected to analysis of variance, and the mean values were compared using Tukey’s test at 5% probability. The size classification of the soya bean seeds has no effect on the germination of the seeds that are produced. Higher seed vigour in the NA 5909 RR cultivar, determined by the seedling emergence test, and accelerated ageing in NS 6700 IPRO, were obtained from seeds produced by plants grown from seeds classified as a sieve size of 6.5 mm. For the other cultivars, the size classification of the seeds had no effect on the vigour of the produced seeds.

Resumo em Inglês:

ABSTRACT The spatial variability of soil attributes in terraced areas is poorly studied in the semi-arid region. Considering that multivariate analysis enhances the diagnosis of spatial variability from geostatistics, soil attributes were studied in different zones between terrace channels in semi-arid region, more precisely in a retention terrace area in Canindé (Ceará, Brazil). Soil samples (n = 100) were collected at depths of 0.0 - 0.1 and 0.1 - 0.2 m for descriptive and geostatistical analysis. For multivariate analysis, samples from three zones relative to the terrace channel (Upper, Middle, and Lower) in the 0.0 - 0.2 m layer were considered, with 30 replicates. There was spatial dependence of soil attributes in the two layers studied. Near the channel, in the respective layers, there was higher clay content (13.7% and 14.7%) and higher degree of flocculation (61.3% and 71.7%) compared to the other zones. Water-dispersible clay was higher in the Upper zone (6.5% and 7.7% in the respective layers), while the Middle zone showed higher potential acidity in the evaluated layers (4.8 and 4.5 cmolc dm-3, respectively) compared to the other zones. In the multivariate analysis, there were highlights for the higher sum of bases in the Upper zone (18.9 ± 0.8 cmolc dm-3), higher sand content in the Middle zone (72.6 ± 0.6%), lower potential acidity (2.1 ± 0.2 cmolc dm-3) and higher phosphorus content (12.8 ± 3.0 mg kg-1) in the Low zone. The zone above the terrace channel loses mainly clay and requires practices to increase water and nutrient retention.

Resumo em Inglês:

ABSTRACT Arbuscular mycorrhizal fungi increase water and nutrient absorption from the soil by plants. However, its benefits to plants vary depending on the inoculated species. This study aimed to determine the influence of different species of mycorrhizal fungi on the development and productivity of grain sorghum cultivars. The experiment was conducted in a greenhouse in a completely randomized design in a 2 x 5 factorial scheme, consisting of two sorghum cultivars (BRS 310 and BRS 330) and five treatments (control without inoculation and four species of arbuscular mycorrhizal fungi: Gigaspora margarita, Glomus formosanum, Acaulospora scrobiculata, and Scutellospora pellucida), with four replications. Plant height, stem diameter, leaf area, length, volume, specific surface area, root diameter, shoot dry mass, root dry mass, thousand-grain weight, grain productivity, colonization, dependence, and mycorrhizal efficiency were evaluated. The results showed that inoculation with the species S. pellucida induced higher root and shoot development of plants of the cultivar BRS 310, as well as higher productivity of sorghum grains. The cultivar BRS 330 showed higher root development when inoculated with the species G. formosanum and a higher shoot development when inoculated with the species A. scrobiculata. Mycorrhizal dependence for grain productivity was low and varied with the inoculated species of mycorrhizal fungi. The mycorrhizal efficiency for shoot dry mass was higher with the inoculation of A. scrobiculata and S. pellucida in the cultivar BRS 310 and A. scrobiculata and G. margarita in the cultivar BRS 330.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate development in the following tree species: Acacia mangium Willd, Anadenanthera colubrina var. cebil (Griseb.) Altschu, Casuarina equisetifolia L. ex J. R. Forst. & G. Forst, Handroanthus impetiginosus (Mart. Ex DC.) Mattos, and Colubrina glandulosa subsp. reitzii (M.C.Johnst.) Borhidi under two water regimes in the Irrigated Perimeter of Baixo Acaraú, in the state of Ceará. The experiment was conducted over seven years, with the factors represented by water regimes, species and periods in an arrangement of split-split plots in a completely randomised design repeated over time with four replications of two plants each. The response variables were total height, diameter at breast height, volume, absolute growth rate in height and diameter, and current and average annual increase in volume. After seven years, the species Acacia mangium, Casuarina equisetifolia, Handroanthus impetiginosus, Anadenanthera colubrina and Colubrina glandulosa presented the following respective mean volumes: 0.62, 0.47, 0.45, 0.31 and 0.29 m3 irrespective of the water regime. Despite a reduction in the growth rates of the species during each period, they remained positive, and growth did not stop. The mean values for volume confirm that the species showed similar growth for the water regimes under study. An irrigated regime of up to one year is therefore suggested for cultivating these species in the Irrigated Perimeter of Baixo Acaraú, Ceará.

Resumo em Inglês:

ABSTRACT Maize sowing is crucial for farm production and food security. Technological advancements, such as electric-pneumatic seed metering and integrated software, have been developed to promote economic and environmental sustainability. However, a limited understanding of the physical processes involved in sowing may compromise the effectiveness and reliability of these mechanisms. Besides uneven terrains, slope conditions require scientific investigation to assess their impact on corn-sowing operations. This study aimed to examine corn seed deposition on longitudinal and transverse slopes using a pneumatic seed metering system. The experiment was conducted on a static sowing bench, simulating various inclination angles. Results indicated that longitudinal inclination did not affect seed spacing consistency, while transverse slopes led to a higher incidence of unsatisfactory spacing. The study concluded that longitudinal slopes decrease corn seed deposition precision, which can be mitigated by level cultivation. Conversely, transverse slopes negatively impacted acceptable, double, and missed seed spacing during sowing.

Resumo em Inglês:

ABSTRACT Maize is a demanding crop that is responsive to nitrogen fertilisation, and meeting its needs is essential to avoid a loss of productivity or environmental contamination. Monitoring nutrient status during crop development is fundamental for optimising nitrogen fertilisation, and using spectral sensors can help detect spatial variability in the field. Based on this premise, the aim of this study was to evaluate the effectiveness of three low-cost sensors in detecting variability in the spectral and agronomic characteristics of the maize cultivar, BM 3066 PRO2®, induced by different N doses (0, 100, 200 and 300 kg ha-1) under two cropping systems, no-tillage and conventional. The study employed a camera with a sensor in the visible region of the spectrum (RGB), a camera in the visible-infrared region (OCN), both mounted on a drone, and a portable chlorophyll meter. Spatial variability was assessed during the crop cycle using the normalised difference vegetation index (NDVI) and chlorophyll index. The results showed that the NDVI(ON) vegetation index from the OCN sensor was more effective at differentiating the treatments than was the NGR vegetation index from the RGB sensor. Furthermore, the chlorophyll b index was better at detecting variations induced by different nitrogen doses, outperforming the vegetation indices obtained by means of aerial images. The airborne sensors under test are more suitable for detecting early spatial macro-variability, while the chlorophyll meter is more effective at assessing the degree of nitrogen deficiency.

Resumo em Inglês:

ABSTRACT Several species of harmful grass weeds were voluntarily brought in by man, mainly with the specific purpose of produce forage. These species compete with crops for physical area and environmental resources, can host pests and diseases, and interfere on harvesting. This work aimed to evaluate in field conditions, the effects of different specific seed weight and sowing depths on the emergence of the species Urochloa brizantha cv. marandú. It was adopted a randomized blocks design with four replications and the treatments arranged in a 6 x 3 factorial scheme, with six sowing depths (1.0, 2.0, 4.0, 8.0, 12.0 and 16.0 cm) and three specific seed weight (low, medium, and high). The treatment effects were evaluated by seedling emergence in field. The marandu-grass seedlings emerged until 12 cm depth, regardless of specific seed weight and year. Sowing depths between 1.0 and 4.0 cm depth have promoted the greater percentage of emergence, and the lowest average time and speed index for emergence of seedlings on field, regardless of the specific seed weight. High-specific weight seeds resulted in greater percentage of emergence on field, speed and synchronicity index of emergence of marandú-grass seedlings. Sowing depths higher than 1.0 cm induces a delay on marandú-grass propagation.

Resumo em Inglês:

ABSTRACT During the germination process, seeds are susceptible to abiotic and biotic stresses, such as attacks by pests and pathogens. In this context, chemical treatment of seeds can promote physiological and morphological changes in seeds and seedlings, in addition to protecting seeds. Two experiments were conducted with the following objectives: (I) assess the effect of soybean seed water content on seedling emergence under different water availability conditions; (II) assess the effect of chemical treatment of soybean seeds on seedling emergence under water stress conditions. In the first experiment, seeds of four cultivars had their water content adjusted to 8, 11, and 14% and were sown in soil under four water potential levels (-0.01; -0.02; -0.10 and -0.40 MPa). In the second experiment, seeds of the same cultivars were treated using metalaxyl, fludioxonil and thiamethoxam, and untreated seeds were used as controls. Sowing was carried out in soil under four water potentials, and seed quality parameters were evaluated in both experiments. The data subjected to analysis of variance, and the means were compared using the Tukey test at 5% probability level. There is no restriction on sowing soybean seeds with water content between 8 and 14% when the soil is under full water availability. Under conditions of soil water restriction, it is recommended to use seeds with water content between 11 and 14%. Under water deficit conditions, treated soybean seeds show better membrane maintenance and superior performance in seedling emergence.

Resumo em Inglês:

ABSTRACT The use of cold plasma is effective in overcoming seed dormancy. However, its effects, both in the long-term and during storage, is still not fully understood. The aim of this study, therefore, was to evaluate the immediate and post-storage effect of atmospheric plasma on the seeds of Pityrocarpa moniliformis in overcoming seed coat dormancy. The seeds were treated with plasma for 0, 1.0, 2.0, 3.0, 4.0 and 5.0 minutes. Following application, 50% of the seeds were stored for two years while the remainder were submitted to immediate analysis. The seeds were evaluated for germination and the germination speed index, in addition to seedling length and dry weight. The experimental design was completely randomised, and included regression analysis. The plasma treatment resulted in an increase in the germination rate and vigour of the seeds, both immediately after exposure and after two years of storage. In particular, the seeds treated for five minutes showed around 39% germination, which was outstanding compared to seeds from other exposure times. Plasma is effective in overcoming seed coat dormancy in seeds of P. moniliformis treated for five minutes and tested immediately. The effect of plasma on the seeds of P. moniliformis after storage was less for all the conditions under test.

Resumo em Inglês:

ABSTRACT Crop pollination is indispensable for global food security. Studies that summarize the knowledge about pollination of specific crops are relevant because they identify the distribution of pollinators, guide pollinator management and conservation policies, and highlight knowledge gaps. Zucchini is cultivated in several countries, and its production is essentially dependent on pollinators. We aimed to integrate global data on zucchini pollination and answer the following questions: (1) What are the topics addressed and what are the trends of the results? (2) Which organisms pollinate zucchini, and how are they globally distributed? (3) What are the knowledge gaps? We performed a systematic literature review, built a network of countries and pollinators, and compared data on the efficiency of specific pollinators. Studies were conducted in 16 countries. Most studies investigated the frequency and diversity of floral visitors. Other approaches were discussed. Zucchini flowers fed 116 species of pollinators, especially bees. Six countries had almost exclusive groups of native pollinators. Apis, Bombus, and Peponapis were the most frequently recorded bees. Areas with high habitat diversity improve pollination. There was a significant difference in productivity when pollination was carried out by bees compared with pollination by Syrphidae. The main knowledge gaps are (1) the determination of which native, manageable pollinators are efficient for maximum zucchini production, (2) the investigation of how pollination influence fruit nutritional composition and seed quality, and (3) the identification of pollinators to the species level.

Resumo em Inglês:

ABSTRACT Despite having a vast area for agricultural production, Brazil is highly dependent on mineral sources for phosphate fertilisers, making their use unsustainable and highly dependent on the international market. The aim of the present study was to evaluate the effect of different sources of phosphate fertiliser and the depth of application on the development and productivity of maize over two crop seasons. A randomised block design was used in a 3 × 4 factorial scheme comprising 12 treatments, with four replications. Three sources of phosphorus were tested: single superphosphate (SSP), Top-Phos® (TOP-PHOS) and reactive natural phosphate (RNP), in addition to four methods of application (broadcast application [0.00 m] and in-furrow application at three depths [0.05 m, 0.08 m and 0.11 m]). The following parameters were evaluated: final plant stand, plant height, stalk diameter, ear insertion height, number of rows per ear, number of grains per row, 1000-grain weight, and grain productivity. The data were submitted to analysis of variance using the F-test at a level of 5%, and to principal component analysis (PCA) with biplot graphical analysis. The use of SSP and Top-Phos® increased productivity and the ear insertion height compared to the use of RNP. Applications made at a depth of 0.11 m were the most efficient. Seasonal variables affected productivity, with Top-Phos® showing a greater correlation with the yield metrics at greater depths.

Resumo em Inglês:

ABSTRACT Successive applications of phosphate fertilisers can exceed the phosphorus (P) requirements of plants and soil, resulting in surface accumulation and loss to aquatic systems, and therefore require monitoring. The aim of this study was to determine a mathematical model for the critical limit for phosphorus in the environment (CLPE) in a Red Latosol of the Cerrado, and to monitor the amount of P in the soil of 46 rural properties in the micro watershed of the Ribeirão Abóbora River. Sand was added to a dystroferric Red Latosol to simulate soils with textures of 10%, 20%, 30%, 40% and 50% clay, in order to quantify the maximum P adsorption capacity (MPAC) and determine the CLPE. Soil from 46 rural properties that make up the micro watershed of the Ribeirão Abóbora River was collected, and the P and clay content was determined. The MPAC decreased proportionally to the reduction in clay content. Th e estimating equation to determine the CLPE for the Red Latosol of the Cerrado is CLPE = 16.64 + 0.432* (% clay), which can be simplified to CLPE = 20 + 0.5* (% clay). The P content on four of the properties in the micro watershed of the Ribeirão Abóbora River is greater than the CLPE. It is therefore recommended that the use of phosphate sources be suspended until appropriate P levels return, and that close attention be paid to these properties so that P values again reach acceptable levels, and no P is transferred to the water sources.

Resumo em Inglês:

ABSTRACT Delays in soybean harvesting can limit seed viability and vigor. In this study, soybean cultivar seeds’ physiological and sanitary quality was evaluated in response to harvest delay. The experimental design used was completely randomized blocks, arranged in a split-plot scheme, with three replicates. The plots were represented by the cultivation of two soybean cultivars (BMX Bônus IPRO and BMX Olimpo IPRO), while the subplots were represented by three harvest times [0, 7, 14 days after the seed’s full maturity (stage R8)]. The following characteristics of the physiological and sanitary quality of the seeds were measured: water content, plant emergence, total dry matter, germination, accelerated aging, electrical conductivity, and seed health. The delay in the soybean harvest affects the seeds’ physiological and sanitary quality. Seeds harvested seven days after full maturity have a higher incidence of Aspergillus flavus and Macrophomina sp. In comparison, seeds harvested 14 days after full maturity have a higher incidence of Phomopsis sp. and Fusarium sp.

Resumo em Inglês:

ABSTRACT The cultivation and consumption of lentils has been gaining importance in recent years due to the high nutritional value of the grain. Research related to seed technology is therefore important in providing high-quality seeds for the market. The aim o f this study was to adapt the accelerated ageing test and evaluate the potential of FT-NIR spectroscopy for classifying lentil seeds based on physiological potential. Seven batches of lentil seeds were subjected to tests to characterise their physiological potential. The accelerated ageing test included the traditional method (100% RH) with an alternative method using saturated saline solution (76% RH) at 41 °C for 24, 36, 48 and 72 hours. NIR spectra were also obtained, taking 200 spectral readings from each batch that were individually processed for 30 seconds. Following the spectral analysis, the seeds were submitted to tests of germination and accelerated ageing to validate the technique. The PLS-DA technique was employed, using 70% of the data for training and 30% for validation. Different pre-processing methods were used, including the standard normal variate (SNV), multiplicative scatter correction (MSC), and the 1st and 2nd Savitzky-Golay (SG) derivatives. It was concluded that the accelerated ageing test at 41 °C for 48 hours using the traditional method (100% RH) was the most efficient way of evaluating the physiological potential of the lentil seeds. The models derived from the FT-NIR spectral data were 99% accurate in predicting the class of physiological potential of the batches.

Resumo em Inglês:

ABSTRACT One of the main phytosanitary problems in major crops are phytonematodes, which are characterised as difficult to control. In view of this, biocontrol, through the use of biological agents, has become a driving force in controlling these pathogens. The aim of this study was to evaluate the compatibility of microorganisms, and detect the possibility of antagonistic effects, influence on growth, or synergistic action when microorganisms are jointly applied to crops. Microbiological analyses were carried out to observe the interaction of the fungus Trichoderma asperellum with the bacteria Bacillus subtilis and Bacillus methylotrophicus. It was found that the interaction between the genera Bacillus and Trichoderma did not promote any increase in the fresh or dry weight of the roots or shoots of the soya plants; however, based on the results of the microbiological analysis of the fungi and bacteria, the interaction was found to be promising, particularly in the evaluation carried out on the seventh day. Considering the number of viable spores, the interaction between B. subtilis + T. asperellum showed better results than B. methylotrophicus + T. asperellum. The Interaction between the genera Bacillus and Trichoderma showed the potential for joint use in the biological control of the soya bean.

Resumo em Inglês:

ABSTRACT The search for cropping systems that aim to have the best area use, optimize production, and guarantee financial profitability to the producer and their establishment in the field are challenges of modern research. Thus, the objective of this study was to evaluate the productive and monetary viability of intercropping radish and coriander fertilized with equitable amounts of hairy woodrose and roostertree biomass from the Caatinga ecosystem at different coriander population densities in two cropping seasons. The experimental design used was randomized blocks, with treatments arranged in a 4 × 4 factorial scheme with four replications. The first factor was constituted by four equitable amounts of hairy woodrose and roostertree biomass (20, 35, 50 and 65 t ha-1 on a dry basis), and the second factor was constituted by coriander population densities (40, 60, 80 and 100% of the recommended density for monocropping, RDM). The greatest agronomic and monetary advantages of intercropping radish with coriander were obtained with a land equivalent coefficient and a monetary equivalence ratio of 0.42 and 0.76, respectively, in the amounts of hairy woodrose and roostertree biomass of 20 and 39 t ha-1 added to the soil, in the coriander population density of 100% of the RDM. The coriander green mass yield and commercial productivity of radish roots optimized in the intercropping were 1.25 and 14.90 t ha-1 when fertilized with 65 t ha-1 of green manures biomass in the coriander population density of 100% RDM.

Resumo em Inglês:

ABSTRACT The chickpea (Cicer arietinum L.) is the third most cultivated legume in the world and the second most consumed. One of the main problems in producing seed of this species is the mechanical damage generated when harvesting or during post-harvest. With the aim of developing a protocol for rapid iodine testing, the aim of this study was to determine the most suitable exposure time for chickpea seeds in iodine solution, and the most appropriate concentration for staining naturally or artificially damaged seeds. Concentrations of 5%, 10% and 15% (commercial product containing 2% iodine) were tested on both intact and artificially damaged seeds for an immersion time of 2.5, 5.0, 10.0, 15.0 and 20.0 minutes. The correlation between the colour and the physical and physiological properties of ten seed batches exposed to 10% iodine for 10 and 15 minutes was also evaluated. The data were submitted to univariate and multivariate analysis. The iodine test, at a concentration of 10% of the commercial product (iodine concentration of 2%) for 15 minutes, is effective in evaluating the level of mechanical damage in chickpea seeds, due to the negative correlation between the colour of the seeds in the test and the physical and physiological qualities of the seeds.

Resumo em Inglês:

ABSTRACT The recognition of oocytes, in their maturational stages, allow estimate the ovarian development and the type of spawning of a species. Although, distinguishing oocytes on histological images requires a visual and subjective interpretation by the specialist. With the development of deep learning techniques, automatic object detection has become an important mechanism for this task. However, studies that use deep learning techniques have not been widely explored for the analysis of fish oocyte samples so far. In this paper, we propose the use of YOLO, a family of convolutional neural networks, for oocyte morphology detection of Centropomus undecimalis fish. The research uses an image database with 5,680 oocytes with different maturation stadiums (PV - pre-vitellogenesis, VI - early vitellogenesis and VF - late vitellogenesis), in histological images, divided into training, testing and validation, and detection performed by YOLOv3, YOLOv4, and YOLOv5 architectures. The results obtained were promising, highlighting that the YOLOv5l model, in the detection of oocytes of the VF class, reached the best values in the metrics precision, recall, mAP@.5 and mAP@.95 with 85.4%, 95.3%, 95.7%, and 75.9%, respectively. When considering all classes, YOLOv5l was the model that obtained the best results in the analyzed metrics.

Resumo em Inglês:

ABSTRACT High soybean grain yield is based on adequate crop management, mainly on disease prevention and control, especially Asian soybean rust (ASR), which causes great crop damage. This study aimed to evaluate the ASR chemical control with different fungicide mixtures in three soybean-producing areas in Brazil during two consecutive crop seasons. Four fungicide treatments [T1: benzovindyflupyr + picoxystrobin, T2: benzovindyflupyr + azoxystrobin, T3: fluxapyroxad + pyraclostrobin, and T4: inpyrfluxam + tebuconazole] were evaluated with five replications. Phytotoxicity damage, ASR disease severity, plant defoliation, 1,000-grain weight, and grain yield were evaluated. The results were relatively consistent among all regions and between the crop seasons, indicating that the treatments have similar responses when applied in diverse conditions. The T3 and T4 treatments presented higher phytotoxicity, lower disease severity, lower plant defoliation, and higher 1,000-grain weight and grain yield. The presence and damage caused by ASR tend to increase after the second soybean crop season in the same area, suggesting a loss of efficiency of the evaluated fungicides.

Resumo em Inglês:

ABSTRACT The early seedling stage is one of the most vulnerable and critical growth stages in the plant life cycle and determines the final plant stand and yield. Corn hybrids have distinct degrees of drought tolerance, and exploiting this characteristic is important to enhance agricultural production in many tropical regions of the world. Fourteen corn hybrids commonly grown in the central-western region of Brazil, in Cassilândia, Mato Grosso do Sul, were assessed for drought tolerance during the early plant growth stage. Plants were grown in the Plant Ecophysiology Laboratory under non-stressful (control) and stressful (moderate drought) conditions for 28 days. Drought stress was induced with an -0.30 MPa iso-osmotic solution prepared with polyethylene glycol (PEG-6000). The emergence rate, seedling length, and seedling dry matter were measured, and then drought tolerance indexes were calculated. Our results showed that root length is an important morphological trait for plant adaptation to drought stress conditions. Therefore, plant breeding programs should select corn genotypes with longer roots to develop commercial hybrids with superior performance under limited soil water availability. The corn hybrids FS 575 PWU, GNZ 7757 VIP3, LG 36745 PRO4, and MG 545 PWU have greater tolerance to drought stress and are the most suitable genotypes to be grown in conditions of low soil water availability. The AG 8088 PRO2 corn hybrid has greater susceptibility to drought stress and should not be recommended for cultivation in conditions of reduced soil water availability.

Resumo em Inglês:

ABSTRACT Pineapple is a non-climacteric infructescence that needs to be harvested at the highest quality, and it is crucial to determine the ideal harvest point. This work evaluates changes in quality, bioactive compounds, expression and enzymatic activity and antioxidant metabolism during maturation of cv Vitória pineapple, recently introduced in commercial orchards, in order to define the harvest point. ‘Vitória’ pineapple infructescence were harvested from commercial planting in five maturity stages and five replications: 100% green (TG), break (B), 75% green and 25% orange (GO), 25% green and 75% orange (OG), 10% green and 90% orange (PO), and 100% orange (TO). In ‘Vitória’ pineapple during maturation, color evolution was clearly shown by the color index (CI) and firmness was higher in TG, G, BP stages. Soluble solids and titratable acidity increased as a function of the maturity stages. The ascorbic acid content was higher in the TG and G, while the yellow flavonoids, PET, and carotenoids higher from OG to PO maturity stages. Antioxidant activity by ABTS•+ and DDPH radicals were higher in the PO stage. The moleculr weight of the antioxidant enzymes regardless the maturity stages was estimated at 47 kDa POD, 28 kDa SOD, and 37 kDa APX. By gel electrophoresis, the SOD, APX, and POD accumulations were higher at earlier maturity stages, whereas the activities were higher at the TO maturity stage. Altogether, the highest quality and functional properties in ‘Vitória’ pineapple, as defined by the highest contents of bioactive compounds and higher antioxidant, activity, were found mainly in the maturity stage PO, which surely value fresh consumption.

Resumo em Inglês:

ABSTRACT Seeking strategies to promote acidity correction and increase the availability of Ca at depth in the soil are crucial to ensure the sustainability of areas managed under no-tillage practices. The objective of this study was to evaluate the soil chemical attributes and soybean performance after cover crops and acidity management through liming using the method of Ca and Mg saturation in the effective cation exchange capacity (ECEC), and gypsum application at variable rates to increase Ca saturation in the subsurface The experiment was carried out in Guarapuava, PR, Brazil in an Oxisol, assessing two factors, (1) cover crops: fallow, oat + turnip and polyculture; and (2) acidity management: without correction and areas with lime (calcitic + dolomitic) or lime + gypsum. The soil chemical attributes were evaluated: pHCaCl2; exchangeable Al3+; H+ + Al3+; Ca2+; Mg2+; S-SO42-; V%; Ca2+/ECEC and Mg2+/ECEC. The chlorophyll index and soybean performance were evaluated through yield components. The cover crops of oat + forage turnip and fallow contributed to the reduction of soil acidity in the 0.35 m layer, reaching the range considered ideal (pH = 5.0) for soybean cultivation. Oats + forage turnip accumulate more Mg2+ and increase base saturation in the 0.05 m layer compared to fallow and polyculture, while also reducing potential acidity in the 0.15 m layer compared to polyculture. When associated with gypsum, lime increased Ca2+ levels in the 0.15 m layer and Mg2+ levels in the 0.15 m and 0.35 m layers.

Resumo em Inglês:

ABSTRACT Genetic divergence for agronomic traits in common bean lines can be analyzed with and without multicollinearity and by different hierarchical methods, which can lead to errors in the interpretation of results obtained from dendrograms. The objectives of this study were to evaluate the variability and genetic divergence of common bean lines for agronomic traits and to analyze the clustering pattern of hierarchical methods obtained with and without multicollinearity. The study involved data from three experiments in which 12 Mesoamerican bean genotypes were evaluated for 17 agronomic traits. Genetic divergence was analyzed through four hierarchical methods, considering two degrees of multicollinearity: severe (with multicollinearity) and weak (without multicollinearity). Ten of the 17 agronomic traits showed a significant genotype × environment interaction effect, indicating response variability of the genotypes in different growing environments. When performed with and without multicollinearity, the hierarchical methods resulted in varied clustering patterns for the genotypes regarding agronomic traits. When analyzed with and without multicollinearity, the furthest neighbor and Ward methods revealed low cophenetic correlation coefficients (≤ 0.69), explaining why the generated dendrograms do not adequately represent the variation observed between common bean genotypes. The unweighted pair group method with arithmetic mean (UPGMA) and nearest neighbor methods implemented without multicollinearity provide a high cophenetic correlation coefficient (0.76). However, the nearest neighbor method is more discriminative in allocating the common bean genotypes into different groups, allowing for a better recognition of differences regarding agronomic traits.

Resumo em Inglês:

ABSTRACT Abrus precatorius L. has been the subject of research to develop drugs with improved therapeutic profiles for the treatment of infectious diseases such as visceral leishmaniasis, which has very high mortality. Commercial cultivation is necessary to meet the demands of the pharmaceutical industry; however, cultivation can be hampered by the presence of integumentary dormancy in the seeds. The aim of this study was to evaluate the effects of different pre-germination treatments and different temperatures on germination in seeds of A. precatorius. The experiment was completely randomised in a 4 x 3 factorial scheme corresponding to four methods for breaking dormancy (intact seeds - T1; immersion in sulphuric acid for 30 minutes - T2; immersion in sulphuric acid for 45 minutes - T3; immersion in 20% caustic soda for 60 minutes - T4) and three temperatures during the germination process (25 °C; 30 °C; 35 °C). At 25 °C and 30 °C, chemical scarification with caustic soda results in a lower rate of germination compared to scarification with sulphuric acid, while at 35 °C, germination was higher. The seeds of A. precatorius show higher germination at 30 °C when previously immersed in sulphuric acid for 30 or 45 minutes. This information is important for viable commercial cultivation.

Resumo em Inglês:

ABSTRACT The objective of this study was to assess the responses of sorghum hybrids to drought and select the most significant morphophysiological indicators to differentiate the hybrids grown under water deficit and well-watered conditions. Two field experiments were conducted simultaneously one under well-watered and the other under water deficit conditions after the pre-flowering stage, evaluating four contrasting grain sorghum hybrids (DKB 540, BRS 310, BRS 332, and 50A10), in a randomized block experimental design with four replications. Means were subjected to individual and joint analysis of variance, and the effects of water conditions and sorghum hybrids were compared using the F-test (p < 0.05) and the Tukey's test (p ≤ 0.05), respectively. Multivariate canonical variable analysis and Pearson correlation were also applied. Water deficit significantly reduced grain yield in 23.9%. The higher grain yields of the evaluated sorghum hybrids are associated with the higher relative chlorophyll content, photosynthetically active leaf area, panicle diameter and mass, grain mass per panicle, threshing index, and 100-grain mass, and the lower number of lodged plants. Grain mass per panicle, 100-grain mass, panicle mass, number of lodged plants, relative chlorophyll content, and leaf area are the most important indicators for explaining drought tolerance variations in grain sorghum hybrids grown under water deficit and well-watered conditions.

Resumo em Inglês:

ABSTRACT The possibility of producing animal bone ash from sources other than cattle, and the determining effect of prolonged calcination, has encouraged investigation into bio-based fertilisers. The aim of this study was to develop and characterise calcined bone ash using different animal sources and heat treatments. Femurs from cattle, pigs and sheep were subjected to heat treatments of 2 or 4 hours, and the ash (CBA1, CBA2 and CBA3) was compared to a commercial bone ash of unknown processing (CCBA-Unk). The data analysis included descriptive or inferential statistics with ANOVA and Tukey's post-hoc test or linear regression. Production analysis showed that CBA1 and CBA3 had higher yields than CBA2 after 2 h, while only CBA1 still differed from CBA2 after 4h (p < 0.05). In the physical and chemical analyses, the ash calcined for 4 h presented both a clearer and more uniform granular morphology than did the ash calcined for 2 h and CCBA-Unk, with a high concentration of minerals, reaching twice the levels of phosphorus and calcium compared to CCBA-Unk. In the ecotoxicological analysis with Artemia salina, all the ashes under test were non-toxic, with 4 h CBA1 and 4 h CBA3 proving safer than the other experimental ashes, reaching four times and twice the LC50 of CCBA-Unk, respectively. Bone ash from cattle or sheep bones calcined for 4 h proved to be more promising than from pig bones or when calcined for 2 h for generating nutritional products for acidic soils.

Resumo em Inglês:

ABSTRACT The application of pesticides is essential in modern agricultural production. The concept of drift refers to the undue displacement of a product, which moves to areas outside the intended target, usually due to air currents. The aim of this study was to evaluate the drift potential of conventional spray tips and those incorporating drift reduction technology, at wind speeds both suitable and unsuitable for application. The following spray tips were used: ConeJet TXVS12, Teejet TT 110-02, Teejet TTI 110-02, and Hypro GA110-03. A wind tunnel was used to generate and control the flow of air. The pressure used was 300 kPa. The wind speeds were 6 and 10 km h–1. The spray bar was mounted with the spray tip 50 cm from the ground. The spray solution included water and tracer dye. Polyethylene thread was used for the collectors, which were placed at four different distances (1, 2, 3, and 4 m) and five different heights (0.1, 0.2, 0.3, 0.4, and 0.5 m). The liquids were analysed in a spectrophotometer. At a wind speed of 10 km h–1, a distance of 1 m and a height of 0.1 m, the drift values were 13.41%, 7.15%, 3.13%, and 5.11% for the ConeJet TXVS12, TT 110-02, TTI 110-02, and GA110-03, respectively. It was found that drift potential increased with the increase in wind speed but was reduced with the increase in distance and height. Drift reduction technology using air induction proved to be the best strategy when choosing the correct spray tip for reducing drigt.

Resumo em Inglês:

ABSTRACT The species Porphyra, Pyropia, and Neopyropia are widely cultivated and consumed worldwide due their valuable nutraceutical properties. These red algae are rich in essential macronutrients, including carbohydrates, lipids, proteins, and minerals. They also contain bioproducts beneficial to human health, such as pigments (phycobiliproteins), phenolic compounds, polyunsaturated fatty acids (PUFAs), and polysaccharides, which exhibit antioxidant, anti-inflammatory, neuroprotective, and anti-obesity activities. These algae are particularly important as edible seaweeds, being most notably used in the production of Nori. This review examines recent research on the nutritional value of Nori species, based on 17 selected articles. The data were organized according to protein, carbohydrate, lipid, and ash content. Additionally, we explore the bioactive compounds found in these species, such as pigments, fatty acids, and phenolic compounds. Our discussion also emphasizes the economic potential of Nori in Brazil. Despite the country's rich biodiversity, Brazil remains a major importer of algae for human consumption. However, there is significant potential for expanding its presence in the aquaculture sector, creating opportunities for the cultivation of Nori species. These growing prospects could pave the way for the sustainable exploitation of this resource in both national and global markets.

Resumo em Inglês:

ABSTRACT Different growth regulators have been applied to several medicinal plant species to help increasing secondary metabolites’ production in them. The aim of the current study is to analyze the effect of growth regulators’ application, at different concentrations; on Melissa officinalis dry weight production, total phenol and soluble protein contents, and essential oil content and chemical composition. The study has followed a completely randomized design, at 3 × 3 + 1 factorial arrangement, which comprised three growth regulators [naphthalene acetic acid (NAA), benzylaminopurine (BAP) and gibberellic acid (GA3)] at three different concentrations (25, 50 and 100 mg L−1), as well as the additional treatment (control), with 4 replications. Growth regulators applied at different concentrations have significantly influenced Melissa officinalis growth. GA3 and NAA regulators’ application at 100 mg L−1 has favored the shoot length and total leaf area of the investigated species. BAP application on leaves, at the highest concentration, led to apical dominance loss; however, the lowest concentration of it has favored soluble protein concentrations in the leaves. BAP application at 25 mg L−1 has favored protein concentrations in the leaves. The highest total phenol contents were observed in plants sprayed with increasing GA3 and BAP doses; they did not differ from the control treatment, only. Essential oil compounds varied depending on the adopted growth regulator type and concentration. GA3 application at the lowest dose (25 mg L−1) resulted in citral content increase by 18% and in citronellal compound content gain ranging from 8% to 10%.

Resumo em Inglês:

ABSTRACT Silicate rocks derived from mining waste, particularly siltstone powder, have the potential to function as a nutrient source in agriculture. It is worth noting that their effectiveness can be enhanced when combined with limestone. This study aimed to assess the agronomic efficiency of using siltstone powder in controlled environments. The experiment utilized soils with different textures (Typic Quartzipsamment (TQ) and Oxisol (OX)). The soils were incubated with doses of rock dust (0, 4, 8, 16, and 32 t ha−1) for 60 days, followed by chemical attribute analysis. Subsequently, four separate pot experiments were conducted, involving maize and bean cultivation with four replications. During plant flowering, the production of dry mass and accumulation of macronutrients and micronutrients were evaluated. TQ soil with the highest dose of rock dust exhibited significantly higher levels of potassium, calcium, and magnesium compared to untreated samples: ten, twenty, and eight times higher, respectively. Ox samples with the highest dose showed double the levels of magnesium, and four times the levels of potassium and calcium compared to untreated soil. The highest dose of rock dust increased pH by 49% in sandy soil and 38% in medium soil. Maize plants showed 40% and 200% increases in shoot dry matter in TQ and OX, respectively, at the lowest rock dust dose. Similarly, bean plants showed 126% and 283% increases in shoot dry matter in TQ and OX, respectively, at the lowest rock dust dose. The rock dust shows promise as a nutritional management option for crop cultivation.

Resumo em Inglês:

ABSTRACT In Brazil, most summer crops are grown under no-tillage (NT), however machine traffic and the unplanned use of crop successions can lead to consolidation or compaction of the soil. The aim of this study was to determine the long-term effects of chiseling and cropping systems on the penetration resistance of an Oxisol. The experiment began in March 2015, and included the following tillage systems: (1) no-tillage; (2) no-tillage with chiseling at the start of the experiment using a five-shank chisel plow (A); (3) no-tillage with chiseling at the start of the experiment using a four-shank chisel plow (B); (4) no-tillage with annual chiseling (2015, 2016, and 2017) using chisel plow A; (5) no-tillage with annual chiseling using chisel plow B. The crops used in succession to the corn were black oats, common vetch, forage radish and mixed crops (black oats + common vetch + forage radish). The soil penetration resistance (PR) decreased in each of the treatments compared to the initial condition of the soil. The chiseling treatments had similar values for PR (Tukey’s test, p > 0.05), indicating ephemeral changes and reconsolidation of the soil in 6 to 12 months. The 0.10-0.20 m layer had the highest PR, close to the critical limit; however, the higher PR values under NT did not affect grain yield in the corn. In conclusion, there is no need for chiseling the soil under NT when a corn/winter cover-crop succession is adopted for three years.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the performance of white oat in the presence of phyllite and basalt dusts associated with Azospirillum brasilense inoculation. The experiment was conducted in a completely randomized design (n = 5) with the following treatments: FB, fertilizer + basalt dust; FP, fertilizer + phyllite dust; FA, fertilizer + Azospirillum brasilense; FBA, fertilizer + basalt dust + Azospirillum brasilense; FPA, fertilizer phyllite dust + Azospirillum brasilense; C, Control. The following variables were evaluated: plant variables - emergence speed index (ESI), Fresh matter (FM), dry mass (DM), root length (RL), plant height (H) and root dry mass (RDM); and soil variables - phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), aluminum (Al), potential soil acidity (PSA), base saturation (BS) and cation exchange capacity (CEC). Phyllite application resulted in lower RL, but promoted the highest H and FM. On the other hand, basalt application increased RDM production when associated with inoculation. In addition, there was an increase in the base content of the soil when phyllite dust and basalt dust were applied. It can be observed that, throughout the cuts, the association of rock dusts with inoculation allows more stability of FM and DM production, increasing the forage potential of oat in the third cut by up to 20%. It is concluded that the association of phyllite and basalt with Azospirillum brasilense affects the chemical properties of the soil, promoting benefits to white oat cultivation.

Resumo em Inglês:

ABSTRACT We aimed to assess pasture vegetation cover over two growing seasons using vegetation indices derived from RDB aerial images acquired by drones and multispectral satellite imagery. The study area was already divided into six grazing paddocks grown with forage grasses, three withMegathyrsus maximus cv. Mombaça and three with Urochloa brizantha cv. MG-4. Sampling was conducted during the January and July 2022/2023 growing season. The study adopted precision agriculture principles, generating customized sampling grids for each pasture, with an approximate density of four points per hectare. Field data were collected on pasture height, soil-exposed percentage, chlorophyll content, and pasture green biomass. RGB aerial imagery was acquired using a drone, while multispectral data was obtained from the Sentinel 2A satellite four times. Pasture vegetation cover (PVC) was estimated after calculating the vegetation indices Normalized Difference Vegetation Index (NDVI), Green-Red Vegetation Index (GRVI), and Green Leaf Index (GLI). PVC results indicate a slight degree of pasture degradation during the 2022/2023 growing season. Images captured by UAVs (unmanned aerial vehicles) enabled accurate identification of sparse areas prone to degradation, offering valuable insights to enhance pasture and forage management.

Resumo em Inglês:

ABSTRACT Soybean (Glycine max L.) is a globally important legume that is susceptible to a variety of pathogens throughout its development stages. One effective option for controlling these diseases is the use of biological products derived from fungi of the genus Trichoderma. This study aimed to select Trichoderma strains, maintained in culture collections, as control agents for the pathogens Sclerotinia sclerotiorum, Sclerotium rolfsii, and Fusarium spp. Additionally, it sought to identify strains among those selected that can enhance the agronomic characteristics of soybean plants in the field. Experiments were carried out in vitro, in a greenhouse, and in an experimental field. The T. koningiopsis CEN209 strain showed performance in vitro and in the greenhouse against S. sclerotiorum, S. rolfsii and Fusarium spp., while the T. afroharzianum CEN230 and T. rifaii CEN288 strains obtained better performances against S. sclerotiorum and S. rolfsii. The strains T. azevedoi CEN1242 and T. koningiopsis CEN1513 significantly increased the final soybean yield under field conditions without the occurrence of soil-borne diseases.

Resumo em Inglês:

ABSTRACT Diaphorina citri (Hemiptera: Liviidae) is a primary citrus pest associated with the transmission of pathogens that cause huanglongbing disease (HLB). Parameter estimation is a crucial step in the process of predicting and modelling biological systems. The reproductive and population parameters of D. citri in Citrus sinensis var. Valencia/Citrumelo, and the growth rate and load capacity of the shoots were determined from experimental data employing a logistic function. The sex ratio of D. citri was estimated at 0.49, with a standard deviation of 0.14. The number of immature and adult individuals per shoot per day was estimated at 24.7 eggs shoot−1, 19.2 NI shoot−1 and 13.6 adults shoot−1, with a standard deviation of 3.6, 2.3 and 2.3, respectively. During the nymphal stages NII, NIII, NIV and NV this value reached 15.1 nymphs shoot−1, with a standard deviation of 2.85. Longevity for the adult stage was 37.9, with a deviation of 7.2 days. The lifetime and effective oviposition rate per female were estimated at 7.36 and 10.97 eggs day−1, with a respective standard deviation of 1.99 and 2.5. Egg fertility was estimated at 70.6%, with a standard deviation of 9.4. The growth rate of the shoots was 0.12, with a standard deviation of 0.02. The values of these parameters are fundamental for adapting and correctly applying mathematical models when analysing biological systems and defining strategies of pest control.

Resumo em Inglês:

ABSTRACT Intercropping maize with tropical forages is common in production systems but must be correctly managed during the early stages to avoid a loss in crop yield due to interspecific competition. Applying subdoses of selective herbicides to the maize is a possible way of suppressing forage growth and avoiding this competition. The aim of this study was to evaluate the effects of subdoses of nicosulfuron herbicide on the development of Megathyrsus maximus ‘BRS Zuri’ when intercropped with maize, and how this simultaneous cultivation affects the weed population and the biometric and production variables of the maize and forage. The design was of randomised blocks with four replications and treatments consisting of six subdoses of nicosulfuron herbicide (0, 2.5, 5, 12.5, 25 and 50 g ha−1) in addition to a single crop of maize. The results show that the forage, BRS Zuri, suppressed the growth and development of the weeds. The dose of 50 g ha−1 caused phytotoxicity in the B2360PW maize hybrid. The presence of the forage had a negative effect on grain yield. The herbicide did not suppress the growth of the forage since both its height and biomass were significant. The results show the need for adjusting the dose, the choice of maize hybrid and the time of herbicide application, with a view to minimising possible interference from the forage in the performance of the maize crop.

Resumo em Inglês:

ABSTRACT This research evaluated the efficiency of ethanolic extracts from yerba mate leaves (Ilex paraguariensis), coffee leaves (coffea arabica), and jambolan pulp (Syzygium cumini Lamarck) through the application of the simplex-centroid mixture design, the super modified simplex optimization algorithm, and the functions of desirability, using the induction period (IP) and the rate constant (k) of the biodiesel oxidation reaction at 110 °C as responses. Antioxidant activity was observed in all extracts, manifesting either by reducing the rate constant or extending the biodiesel induction period in comparison to the control sample. The mathematical models derived from the simplex-centroid design exhibited adjusted determination coefficients of 0.990 for the IP model and 0.960 for the k model. Analysis of variance indicated the significance of both models at the 5% significance level for IP and k, with p1 = 7.382 × 10−4 and p2 = 1.177 × 10−3, respectively. The lack of fit was not significant at the same level with p1 = 0.132 and p2 = 0.653, showing that they can be used for predictive purposes. The analysis of the response surface and optimization using the super modified simplex method revealed that higher proportions of coffee leaves extract in the mixture yielded superior IP values and lower k values.

Resumo em Inglês:

ABSTRACT To solve the low recognition accuracy and slow recognition efficiency in traditional rice disease and pest recognition technology, this study adopts a bidirectional encoder representation pre-training model from a transformer for preliminary recognition of rice diseases and pests. At the same time, a bidirectional long short-term memory network is introduced for further recognition, and the model is optimized using conditional random fields to design a fusion algorithm for rice disease and pest recognition. The outcomes denoted that when the learning rate was 0.0001, the loss of the fusion algorithm was 0.04, indicating its high accuracy. In the identification of 6 types of rice diseases and pests, the average training time of the fusion algorithm was 31.4 seconds, the central processing unit occupancy rate was 94.3%, and the memory occupancy rate was 66.4%, proving that the algorithm had high efficiency in disease and pest identification. On the PlantVillage dataset, the accuracy of the fusion algorithm was 94.3%, higher than other algorithms, indicating its good recognition performance. The fusion algorithm effectively improves the rice disease and pest identification accuracy and efficiency, providing strong technical support for preventing and controlling other agricultural diseases and pests.

Resumo em Inglês:

ABSTRACT Leaf analysis is an important instrument that assists in the fertilization management of agricultural crops. However, the delay and high cost of conventional methods make its execution difficult. In this context, vis-NIR-SWIR (visible - near infrared - shortwave infrared) spectroscopy emerges as an analysis tool that is faster, more affordable and without major environmental impacts. Thus, the objective of this study was to quantify leaf macro and micronutrients in mango cv. Tommy Atkins cultivated under irrigation in the Brazilian semi-arid region with the use of vis-NIR-SWIR spectroscopy. 159 leaf samples of mango cv. Tommy Atkins coming from three distinct commercial areas were used. For these samples, the reflectance spectra were obtained for a spectral range from 350 to 2500 nm, and the contents of N, P, K, Ca, Mg, B, Zn, Fe, Mn and Cu were determined by the reference methods. Spectral data were initially subjected to preprocessing techniques. Then, multivariate regression models were developed. For all calibrated models, cross-validation was performed and for the models with better performance, external validation was performed. Regressive models had strong predictive performance for P and Ca (R2 > 0.70), moderate for N and Zn (0.50 < R2 < 0.70), weak for Fe (0.30 < R2 < 0.50) and very weak for K, Mg, B, Cu and Mn (R2 < 0.30). Therefore, vis-NIR-SWIR spectroscopy is a potential complementary tool to quantify the contents of these nutrients in mango cv. Tommy Atkins.

Resumo em Inglês:

ABSTRACT Soaking seeds in gibberellic acid can alter seedling performance by directly affecting reserve mobilization and the formation of vigorous seedlings. The aim of this study was to assess whether common bean seeds with contrasting vigor pre-soaked in different doses of exogenous gibberellic acid (GA3) exhibited changes in reserve mobilization and seedling development. The experimental design was completely randomized, with a 2 x 5 factorial scheme (two cultivars and five GA3 concentrations). The BAF55 and BAF44 cultivars were characterized as high and low vigor, respectively. The parameters assessed exhibited cultivar-dose interaction, demonstrating genetic variability for sensitivity to the hormone. An increase in GA3 doses compromised reserve mobilization in BAF55, with the larger amount of remaining dry mass in the cotyledons indicating that the reserves were not used during seedling development, resulting in lower dry mass. On the other hand, higher hormone doses favored seed reserve use, promoting greater seedling length. GA3 doses up to 0.10 mM L-1 resulted in greater hypocotyl, epicotyl and seedling length and lower cotyledon mass, demonstrating use of the energy reserves previously synthesized in the cotyledon. Thus, while applying the hormone to seeds directly influences seedling architecture, it promotes more efficient use of cotyledon reserves in cultivar BAF44, producing taller, more vigorous seedlings with higher dry mass.

Resumo em Inglês:

ABSTRACT The use of soybeans for human consumption is primarily attributed to their high protein content and diverse phytochemical composition, which are key for improving human nutrition. Given the growing interest in biofortification to enhance the nutritional value of crops, this study aimed to assess the agronomic performance, nutritional, functional and physicochemical composition of soybean lines with both brown and yellow seed coats, with a particular focus on their biofortification potential. To achieve this, we evaluated ten F6 generation soybean genotypes (G1M, G2M, G3A, G4A, G5A, G6A, G7A, G8A, G9A, and G10A), along with a commercial control (G11T), using a randomized block design. Sowing occurred in the second half of November 2020, and after harvesting, grain samples were analyzed for agronomic and biochemical traits, including fatty acids, neutral and acid detergent fibers, minerals (Na and K), proteins, lipids, total flavonoids, total phenolic content, and antioxidant activity (ABTS and FRAP). A previous experiment with extractive conditions related to temperature and extraction method was carried out to evaluate the antioxidant properties. Significant variation in agronomic and proximate traits was observed among the genotypes, and the interaction between genotypes and extraction methods notably influenced antioxidant properties. Genotypes with brown seed coats, particularly G2M, showed high potential for protein and oleic acid content, making them suitable for biofortification and food product applications. The Ultrasonic Bath extraction method proved more effective in extracting ABTS and total flavonoids. These findings suggest that both the seed coat color and extraction method play crucial roles in determining the bioactive and nutritional potential of soybeans, supporting their use in biofortification strategies for enhanced human nutrition.

Resumo em Inglês:

ABSTRACT Seed quality is critical to agricultural yield, and traditional testing can be time-consuming and subjective. Therefore, the use of machine learning can provide an efficient approach for predicting germination. The aim of this work was to investigate algorithms that, together with tetrazolium test data, lead to efficient prediction of soybean seed germination. The experiment was based on the collection and transcription of a database of thousand soybean seed analysis samples containing information on germination and tetrazolium tests (vigor and viability). The algorithms tested were REPTree, M5P, random forest, logistic regression, artificial neural networks and support vector machine, and the inputs tested were viability, vigor and vigor + viability (tetrazolium test) data. The data analysis used the correlation coefficient and mean absolute error as accuracy parameters of the algorithms. The results highlighted the support vector machine as the most effective algorithm for predicting germination, with the viability and vigor + viability inputs showing the best results. This study suggests that the integration of computational intelligence techniques with the tetrazolium test can make the assessment of soybean seed quality more efficient and contribute to fast and efficient decision making in agriculture.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate control of the species Commelina benghalensis and Commelina diffusa using post-emergent herbicides applied alone and in mixture. Two replicated experiments (EI and EII) were conducted to evaluate two species of Commelina, with four to six leaves (EI) and six to ten leaves (EII). The experiments included 27 treatments with the following post-emergent herbicides that were applied alone or in mixture: glyphosate; 2,4-D; triclopyr; dicamba; carfentrazone; saflufenacil; flumioxazine; chlorimuron; cloransulam and diclosulam+halauxifen. Plant control and the transient fluorescence of chlorophyll-a were visually analysed 21 and 42 days after application (DAA). At 42 DAA, plants were collected to determine the shoot dry weight. The data were submitted to ANOVA (p ≤ 0.05) and compared using the Scott-Knott test. The triple mixtures were effective in controlling both species. The triple mixtures that included carfentrazone afforded faster effective control compared to mixtures containing saflufenacil and flumioxazine. Triclopyr gave faster control of both species compared to the other auxinic herbicides. Both species respond differently to auxinic herbicides, and are more difficult to control when they have between six and ten leaves.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate the agronomic traits of soya bean cultivars as well as the physiological quality of the produced seeds based on the initial vigour of seeds from different cultivars subjected to waterlogging stress at different phenological stages. Soya beans of mixed vigour were used, obtained under controlled conditions from the NA5909RG, NS6209RR, TMG7363RR and TECIRGA6070RR cultivars. The study comprised three factors: four cultivars, two levels of seed vigour (high and low), and three cultivation regimes (no waterlogging, five days temporary waterlogging from stage V6, and five days temporary waterlogging from stage R2). The following parameters were determined: number of pods per plant, number of seeds per pod, number of seeds per plant, 1000-seed weight, plant height, number of productive nodes on the main stem, height of the first pod insertion, seed yield per plant, and centesimal protein and oil content. Waterlogging stress results in a reduction in the number of pods per plant, number of seeds per plant, number of productive nodes on the main stem, number of secondary branches, seed yield per plant, oil content, and the physiological quality of the produced seeds. The high vigour of the seeds affords an increase in seed yield per plant, in the 1000-seed weight, number of nodes on the main stem, height of the first pod insertion, and oil content of the seeds.

Resumo em Inglês:

ABSTRACT Evaluating the availability of potassium (K) in soils of the semi-arid region of Brazil is complex, as it varies greatly between soils, especially soils with larger amounts of 2:1 minerals. The aim of this study was to evaluate the efficiency of ammonium acetate, ammonium chloride, Mehlich-1 and mixed ion-exchange resin as extractants in quantifying the K content available to maize plants in soils of the semi-arid region of Brazil. The treatments were distributed in randomised blocks, and included six types of soil (a Red Yellow Argisol, a Fluvic Neosol, two Haplic Cambisols, a Rendzic Chernosol and a Haplic Vertisol) and five levels of K, with three replications. Each plot consisted of a plastic pot containing 3.0 dm3 soil, where two maize plants were grown for 35 days. There was a good correlation between the extractants under evaluation and the amount of K accumulated by the plants. The ion-exchange resin presented a lower K extraction capacity in the more-clayey soils with a higher CEC and greater quantity of 2:1 minerals, and is not recommended for soils with these characteristics. The extraction capacity of Mehlich-1 may be reduced in alkaline soils with high levels of CaCO3 equivalent, and should not be used in these soils. Ammonium acetate extracted the greatest amounts of K from the soils and showed no limitations in any of the soils under evaluation, making it the most recommended for assessing potassium availability in semi-arid soils.

Resumo em Inglês:

ABSTRACT Canonical correlations estimate important relationships between sets of variables, making it easier to manage studies of a large number of characteristics. The aim of this study was to identify the canonical correlations between the seeds, physiological and plant characteristics of soybean, as well as the Pearson linear correlations within each set of characteristics. A randomised block design was used in the field and a completely randomised design in the laboratory, with four and three replications respectively. Canonical groups were defined between the set of plant characteristics (weight and number of nodules, shoot dry weight, number of pods, 1000-grain weight, and grain yield) and the set of seed variables (shoot and root length, plant dry weight, accelerated ageing, electrical conductivity, first count and germination), the set of physiological variables (protein, carotenoid and guaiacol peroxidase content of the grains and leaves) and the plant variables, and the physiological variables and the seeds. Electrical conductivity has a negative correlation with first count and germination. Grain yields are higher when the weight of the plants, the 1000-grain weight, and the number of vegetable parts per plant are greater, while carotenoids are correlated with the chlorophyll levels. Higher levels of protein in the grains and leaves are associated with a higher 1000-grain weight and higher grain yield. The canonical correlation analysis shows that the sets of plant, seed and physiological variables are not independent, and defines the characteristics that should be given priority in the evaluations.

Resumo em Inglês:

ABSTRACT Although the use of alternative substrates in seedling production is still uncommon, the aim of this study was to evaluate the effect of different particle sizes and concentrations of shell powder from Anomalocardia flexuosa on emergence and initial biomass production in seedlings of Crotalaria juncea, varying the composition of the basic substrate components. The experimental design was of randomised blocks in a factorial scheme that included three particle sizes (3 mm, 2 mm and 250 μm), five concentrations (0%, 20%, 40%, 60% and 80%) of shell powder, and three basic substrate constituents (soil, vermiculite and organic compost), giving a total of 45 treatments, with four replications per treatment, in which each experimental plot consisted of 25 seedlings. The following variables were evaluated: seedling emergence, emergence speed index, plant height, number of leaves, collar diameter, dry matter accumulation, H/CD ratio (shoot height to collar diameter), SDW/RDW ratio (shoot dry weight to root dry weight) and H/SDW ratio (shoot height to shoot dry weight). The particle size of the shell powder and the basic constituents of the substrates had no significant effect on the variables under analysis. Regardless of particle size or concentration, the shell powder enhanced the emergence, shoot length (SL), root length (RL), shoot dry weight (SDW) and root dry weight (RDW) of the C. juncea seedlings

Resumo em Inglês:

ABSTRACT Aluminum (Al3+) inhibits plant growth and limits agricultural production in acidic soils with pH ≤ 5.5. However, high-yielding corn hybrids have distinct degrees of Al3+ tolerance. Exploring this trait may be useful to improve the sustainable use of acidic tropical soils. Fifteen corn hybrids commonly grown in the central-western region of Brazil were assessed for Al3+ stress tolerance during the early plant growth stage. Plants were grown under laboratory conditions with solutions containing 1,000 μmol L–1 Ca2+ (control) or 200 μmol L–1 Al3+ combined with 1,000 μmol L–1 Ca2+ (Al stress). Plant emergence and morphological traits were measured to calculate Al3+ toxicity tolerance indices. The results showed that the corn hybrids AG 8701 PRO4, DKB 390 PRO4, and B2800 VYHR had a greater tolerance to Al3+ toxicity. These findings offer preliminary insights for agricultural cultivation of corn in acidic soil conditions. However, the mechanisms of tolerance to Al3+ toxicity of these corn hybrids still remain unknown. Additionally, the greater stability and tolerance of the corn hybrids AG 8701 PRO4 and DKB 390 PRO4 indicate that these genotypes can be used as genitors in breeding programs to obtain offspring with higher tolerance to Al3+ toxicity. On the other hand, the corn hybrids AG 8088 PRO2, AS 1868 PRO4 and BP 2201 VIP3 are more sensitive to Al3+ toxicity and should not be recommended for cultivation in acidic soils. Therefore, greater attention to soil corrective practices should be given when using these corn hybrids in agricultural areas.

Resumo em Inglês:

ABSTRACT Gelatin coatings obtained from fish are a renewable technology with excellent benefits for the preservation of fish products and with high nutritional value, however they are very perishable. This study evaluated the shelf life of Pacific white shrimp (Penaeus vannamei) coated with gelatin extracted from Nile tilapia (Oreochromis niloticus) scales and glycerol, stored frozen at -18 °C for 180 days. For this, the gelatin was extracted and applied at a concentration of 1.5% with 0.2% glycerol in peeled and headless shrimp (treatment G). This group was compared with uncoated shrimp (control group – C), peeled and headless, regarding psychrotrophic bacterial count (PBC), pH, total volatile bases nitrogen, trimethylamine nitrogen, and thiobarbituric acid-reactive substances (TBARS) every 30 days. As a result, the obtained gelatin extraction yield rate was 24.64% and the Total Bacterial Count (TBC) range for control group was 0.70 to 2.32 log CFU/g/estimated, while for treatment G was 0.70 to 1.48 log CFU/g/estimated. The shelf life evaluation showed that the gelatin-glycerol coating solution was effective in the preservation of P. vannamei in PBC, pH, TVB-N, TMA-N, and TBARS parameters. It was concluded that the use of this coating combined with frozen storage can be an excellent alternative to maintain the quality of Pacific white shrimp in the long term.

Resumo em Inglês:

ABSTRACT The soya bean/maize double-crop is seen as the principal grain production system in Brazil; it is, however, vulnerable to competition and infestation by volunteer plants. In crop rotation systems which include different species, cultural weed control can be effective, improving phytosociological indices and reducing costs. The aim of this study was to evaluate the phytosociology and cost of weed control in a soya bean/maize double-crop and in crop rotation systems with different species, between the 2014/2015 and 2022/2023 crop years. Six treatments were used, with four replications. Phytosociological indices were calculated and analysed following the soybean harvest in 03/2014, 03/2017, 03/2020 and 03/2023. The ground cover was evaluated in 03/2023. The costs of weed control were calculated based on the cost of the active ingredients and the agricultural operations. The treatment that included cereal crops in the winter and grain crops in the summer (T2) showed less weed diversity and greater control of Commelina benghalensis and Euphorbia heterophylla compared to the soya bean/maize double-crop. Each of the treatments had adequate ground cover. Costs in the soya bean/maize double-crop were 22.72% higher for the treatment with cereal crops in the winter and grain crops in the summer (USD 162.32 ha⁻1 yr-1). It was found that winter cereals are effective in controlling C. benghalensis and E. heterophylla, and that the soya bean/maize double-crop results in higher costs for weed control.

Resumo em Inglês:

ABSTRACT In melon, characterizing germplasm allows identification of genotypes resistant to leafminers; knowing the genetic control of this resistance is indispensable for use in breeding. In this study, the genetic inheritance of resistance to L. sativae by antixenosis was investigated in the melon accession CNPH 94-244 (PR) in crosses with the susceptible hybrids ‘Goldex’ (PS) and ‘Iracema’ (PS’), generating two populations. The plants were infested by the insect in screened plant enclosures and in the field. In the enclosures, the number of leaf mines and pupae per plant were evaluated; and in the field, a subjective score was attributed and the number of mines per leaf were counted. The genetic studies were based on the mean values and variances in the different generations (PR, PS or PS’, F1, F2, BC1, and BC2), in each population. In the F₁ generation of the CNPH 94-244 × ‘Goldex’ and CNPH 94-244 × ‘Iracema’ populations, non-additive allelic interactions were observed in the genetic control of the evaluated traits. The full model explained the inheritance of the variables, with additive effects being the most significant. Narrow-sense heritability was high for mines per plant (in cages) and number of mines (in the field) in the F₂ generation of the CNPH 94-244 × ‘Goldex’ and CNPH 94-244 × ‘Iracema’ crosses, respectively. The genetic inheritance of antixenosis resistance to Liriomyza sativae in the CNPH 94-244 accession is predominantly additive, being oligogenic for subjective scores and polygenic for mines and pupae per plant in both populations. For the number of mines, inheritance was polygenic in the CNPH 94-244 × ‘Goldex’ population and oligogenic in the CNPH 94-244 × ‘Iracema’ population. Therefore, the CNPH 94-244 accession can be used as a resistant parent in breeding programs targeting leafminer resistance in melon.

Resumo em Inglês:

ABSTRACT Salinity can impair seed germination and seedling development. Understanding plant tolerance to salinity and exploring alternatives to mitigate its adverse effects, such as the use of salicylic acid (SA), may enhance plant establishment in saline environments. This study aimed to evaluate seed germination and seedling development of the 'Biquinho’ and ‘Bode’ cultivars of Capsicum chinense Jacquin under different sodium chloride (NaCl) concentrations, with SA tested as a potential alleviator of salt stress. Treatments followed a 5 × 2 factorial design, with five salinity levels (0, 30, 60, 90, and 120 mM NaCl, corresponding to 0, 3.31, 5.71, 7.84, and 9.68 dS m⁻1, respectively) combined with the presence or absence of SA. Evaluated parameters included the number of normal and abnormal seedlings, ungerminated seeds, root and shoot length, and total dry mass. Salinity reduced seed germination and seedling development in both cultivars. The 'Biquinho' pepper exhibited tolerance up to 30 mM NaCl, as shown by stable total dry mass and greater root growth in the presence of SA up to 60 mM NaCl. In contrast, the 'Bode' pepper was not tolerant to salinity during germination or seedling development, and SA did not mitigate its reduced germination percentage or shorter shoot length.

Resumo em Inglês:

ABSTRACT Vegetative tissues are viscoelastic materials and suffer from internal and external interferences to obtain data for the characterization of their mechanical properties. Quality control tools are likely to detect internal and external problems in processes and indicate anomalies in the system or sampling points analyzed. This research aims to analyze the use of quality control tools to detect problems in experimental procedures and in sampling data to determine mechanical properties of plant tissues. Uniaxial compression tests were performed to determine the modulus of elasticity and tensile strength under three compression ratios of 0.2 mm/s, 0.4 mm/s, and 0.6 mm/s. Shewart individual and moving range charts were used to analyze internal and external problems, respectively, obtained in the MINITAB software. The results showed that the quality control charts were able to detect sample points that negatively impacted the characterization data.