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.