ABSTRACT Bean is among the most consumed and produced crops in Brazil. Given the high demand for food, the search for technologies and controllers to increase the efficiency of agricultural systems has grown. This study aimed to model artificial neural network (ANN) architectures to predict mechanical efficiencies in the semi-mechanized bean harvest. We used a multilayer perceptron network with three inputs (harvest moisture, threshing rotor rotation, and feed rate), two hidden layers of neurons, and one output (efficiency). We evaluated the efficiency in the header, separation on the threshing rotor, cleaning of sieves, and the total efficiency of the machine. ANN was processed by a scripted algorithm to model the network, alternate the number of neurons in hidden layers, as well as to select, test, and validate ANN with less error. ANN was validated by comparing its results with the experimental data. The architectures selected to predict efficiencies were 3-8-15-1 for the header, 3-9-7-1 for the thresher and separation, 3-5-11-1 for cleaning, and 3-15-10-1 for the total operation. ANN predicted satisfactory results with errors below 1% and a high hit rate, thus being valid to predict the efficiencies in the semi-mechanized bean harvest.

RESUMO O controle da ferrugem asiática da soja depende da eficácia do fungicida e da tecnologia de aplicação empregada, entretanto, a arquitetura foliar de cada cultivar de soja também pode ser um fator a interferir no controle da doença. O objetivo do estudo foi avaliar a deposição de calda fungicida e o controle da ferrugem asiática da soja utilizando pontas de pulverização em três cultivares de soja. O delineamento experimental utilizado foi em blocos ao acaso, com tratamentos arranjados no esquema de parcelas subdivididas, em que as parcelas eram três cultivares de soja (SYN 1561 IPRO, M6410 IPRO e M6210 IPRO) e as subparcelas três pontas de pulverização (11002 BD, AIXR 110015 e TTJ60 11002), e uma testemunha sem aplicação, com quatro repetições. Foram avaliados o diâmetro mediano volumétrico, cobertura de gotas, índice de área foliar (IAF), área abaixo da curva de progresso da doença, massa de 1000 grãos e produtividade da soja. Os bicos 11002BD e AIXR11005 fornecem melhor deposição de calda naquelas cultivares com menores índices de área de foliar, no estágio fenológico da soja R1. Os bicos 11002BD, AIXR110015 e TTJ60 fornecem controle da ferrugem asiática comparada ao tratamento controle, independentemente do índice de área de folha da cultivar. A cultivar SYN1561 apresentou a maior produção de grãos e o maior índice de área de folha, independentemente do bico de pulverização utilizado, na época com a maior precipitação pluviométrica.

ABSTRACT The control of Asian soybean rust depends on fungicide efficacy and the application technology; however, the leaf architecture of soybean cultivars may also interfere in disease control. This study aimed to evaluate Asian rust control and fungicide deposition using spray nozzles in three soybean cultivars. A randomized block design was used, with treatments arranged in a split-plot scheme; the plots were three soybean cultivars (SYN 1561 IPRO, M6410 IPRO, and M6210 IPRO) and the subplots three spray nozzles (11002 BD, AIXR 110015 and TTJ60 11002), in addition to a control with no fungicide application, and four replicates. The volume median diameter, droplet coverage, leaf area index, area under the disease progress curve, 1,000-grain weight and crop yield were evaluated. The 11002BD and AIXR11005 nozzles provided better spray deposition in cultivars with lower leaf area indexes at the R1 phenological stage. Nozzles 11002BD, AIXR110015 and TTJ60 ensured better management of Asian rust than that of the control treatment, regardless of leaf area index. Cultivar SYN1561 obtained the largest grain yield and highest leaf area index in the season with the highest rainfall, regardless of the spray nozzle used.

RESUMO A produção agrícola brasileira demanda novas construções rurais, mais sustentáveis, econômicas e adaptadas ao clima. Além disto, estas construções deixaram de ser simples alojamentos, mas também uma forma de valorização dos trabalhadores rurais. Portanto, o objetivo deste estudo foi a criação de um modelo de programação linear de otimização para auxiliar a tomada de decisão na combinação de diferentes técnicas e materiais construtivos, visando avaliar combinações de custo e conforto para unidades habitacionais rurais. O estudo utilizou a problemática de localização de instalações em redes, para através de analogias adaptar uma matriz orçamentária, aplicando três critérios de escolha, sendo custo, tempo de execução e condições de conforto ambiental proporcionado. O modelo foi composto por seis sistemas construtivos, três tipos de alvenaria de fechamento, dois tipos de estrutura de cobertura e quatro tipos de telhas. Foram realizadas simulações para dois Estados brasileiros, com a mesma data base para validação e comparação. Cada variável de entrada resultou em um modelo construtivo diferente. Verificou-se viabilidade de novas tecnologias construtivas baseadas na industrialização, por possuirem agilidade de execução, preços competitivos e matéria-prima sustentável, e na combinação dos critérios ao sistema tradicional de concreto armado. A programação linear permitiu ao usuário atender suas necessidades sobre tomadas de decisão do sistema construtivo, otimizando tempo e recurso.

ABSTRACT Brazilian agriculture production requires new types of rural buildings that are more sustainable, economical, and well adapted to their environment. Furthermore, these buildings are no longer simple living quarters, but a way of valuing rural workers. Thus, this study aimed to create a linear programming model for optimizing decision-making when different techniques and construction materials are combined to build rural housing dwellings, thereby enabling an assessment of both the cost and comfort of such buildings. The research considered localizing network facilities via analogies in order to adapt a budget matrix. Three main criteria were applied: cost, runtime, and the environmental comfort provided. The model comprised six construction systems, three types of sealing masonry, two types of roofing, and four types of tiles. Simulations were performed for two Brazilian states, considering the same reference date of validation and comparison. Each input variable resulted in a different construction model. It was demonstrated that the new industrialized construction technologies are advantageous since they provide faster execution, competitive prices, and sustainable raw materials, whilst the application of the criteria to the traditional system of reinforced concrete is also feasible. The linear programming model offers its users an additional decision-making tool for construction systems, enabling time and resource optimization.

ABSTRACT Machinery traffic intensification has been recurrent in intensive agriculture in annual crops, which may lead to structural soil degradation and, consequently, a reduction of its productive capacity. Therefore, this study aimed to assess the influence of tractor traffic intensification on soil physical attributes and soybean yield components. The study was performed in an Oxisol under no-tillage for 10 years, using a randomized block design with five tractor traffic intensities (0, 2, 4, 6, 8, and 12 passes) and five replications. Density, porosity, macroporosity, microporosity, and penetration resistance were assessed in the soil and stem diameter, number of pods per plant, number of grains per pod, grain weight per plant, thousand-grain weight, and grain yield were assessed in the soybean crop. Tractor traffic intensification changed soil physical attributes, which were not limiting factors to soybean yield under the no-tillage system, providing higher stem diameter, number of pods per plant, grain weight per plant, and grain yield after 12 passes.

ABSTRACT Machine traffic and conventional tillage can cause structural degradation of the soil, affecting the physical attributes and, consequently, the production and longevity of the sugarcane field. The objective of this study was to evaluate the production components of sugarcane cultivars (RB965902, RB985476, RB966928, RB855156, RB975201, RB975242, RB036066 and RB855536) and physical attributes of a Dystroferric Red Latosol (Oxisol) under no-tillage and reduced-tillage systems. The experiment was conducted using a completely randomized experimental design in an 8 × 2 factorial arrangement, with four replicates. The soil attributes evaluated were density, total porosity, macroporosity, microporosity and penetration resistance. The production components evaluated were stalk length and diameter, number of tillers (NT), tons of cane per hectare (TCH), sucrose content (Pol), tons of sucrose per hectare (TPH), soluble solids content (Brix), total recoverable sugars (TRS) and plant fiber. Cultivars RB965902, RB966928, RB855156 and RB985476 have productivity and technological attributes that are superior to the other cultivars, whereas these are lower for RB036066 in both soil tillage systems. Cultivars RB966928, RB855156, RB975242 and RB855536 exhibited higher TCH and TPH in the no-tillage system, and all cultivars displayed equal or higher performances than those observed in the reduced-tillage system. In the no-tillage system, which exhibits lower penetration resistance values between wheel tracks and in the subsurface layer of the planting row (0.20–0.40 m), cultivars RB985476 and RB975242 had a higher NT, and RB855156 had higher stalk lengths and NT.

ABSTRACT Application technology factors may be influenced by changes in plant architecture, such as height and leaf area. This study aimed to evaluate which angle of sprayer displacement in the application of pesticides in relation to the direction of cotton sowing, cultivated in the ultra-narrow row, narrow row, and conventional systems, provides the best application quality characteristics in the different thirds of plants. The experiment was installed in a split-plot design with four replications in the 3 × 4 factorial scheme, composed of three cotton cultivation systems and four angles of sprayer displacement in relation to the direction of the sowing rows. The evaluated characteristics were mean volumetric diameter, density and coverage of droplets, number of droplets, and open area in the interrows without leaf. The upper third presented the highest values of mean volumetric diameter, number of droplets, and density and coverage of droplets for all interrow spacing and application angles. The angle of displacement of 30° in relation to the sowing row presented the best results in relation to the number and density of droplets. The spacing of 0.90 m in the interrows increased the number of droplets, droplet density, and coverage in the lower third of plants.

ABSTRACT With the short period of the sowing process, we observed an increase in the seeder speed set in several soil management systems that may result in decreased soybean yield and problems with penetration resistance. We aimed to assess the penetration resistance (PR) and agronomic characteristics of soybean on soil tillage and sowing speed. The randomized block design in split plot with four replications was used. The treatments consisted of six management systems, applied to the plots: no tillage (NT), no tillage and chiseling (NTc), no tillage and cross chiseling (NTcc), conventional tillage (CT), reduced tillage (RT) and conservation tillage (CsT) and four speeds, (4.6; 5.5; 7,3 and 7.8 km h-1) applied in the subplot at the time of soybean seeding. We observed in the deep layers 0.0 – 0.10; 0.10 – 0.20 and 0.20 – 0.30 m significant effect of tillage systems on the PR of the soil. The NT system showed the highest value of PR compared to other management systems studied. In the NT should be used sowing speeds above 5.5 km h-1 to decrease the compression. Low speeds favor higher yield by improving pods per plant. Speeds in the working range (5-7 km h-1) promote higher productivity by improving the number of pods per plant, and provide better stand.

Objetivou-se, com este estudo, avaliar a influência de diferentes grades amostrais na recomendação de aplicação de calcário em um Latossolo. O trabalho foi desenvolvido em uma propriedade rural localizada em Sidrolândia/MS, região do cerrado brasileiro. No mapeamento dos atributos do solo utilizou-se uma grade amostral regular composta por 99 pontos, distribuídos em uma área de 90 ha. Da grade amostral inicial outras duas foram originadas por meio da exclusão de pontos ou linhas, uma com 51 e outra com 27 pontos. Calculou-se, com base nos resultados das análises de solo, a recomendação de aplicação de calcário em cada ponto amostral. Utilizando técnicas de geoestatística estudou-se a variabilidade espacial da recomendação de aplicação de calcário para cada configuração de grade amostral testada. Por meio de krigagem, mapas de aplicação de calcário foram confeccionados. Após as análises concluiu-se que com a redução do número de pontos amostrais 11% da área de estudo apresentaram superestimativa e 8% subestimativa na dose de calcário recomendada, quando comparada com a recomendação feita utilizando grade com maior número de pontos.

The objective of this study was to evaluate the influence of different sampling grids density in the lime requirements in an Oxisol. The experiment was conducted at a rural property located in Sidrolândia city, Mato Grosso do Sul state, in the Brazilian ‘Cerrado’. In the soil attributes mapping, regular sampling grid was used consisting of 99 points, spread over an area of 90 ha. Other two grids (51 and 27 points) were derived by deleting lines or lines and points from the original one. Based on the results of soil analysis, the lime requirement at each sample point was calculated. Using geostatistical techniques the spatial variability of lime requirement was studied and grid configuration for each sample was tested. By kriging, maps were made. By reducing the number of sampling points, 11% of the experimental area showed an overestimation and 8% underestimation comparing with the lime requirement made using the highest sampling grid density.

Práticas de manejo e semeadura mal conduzidas podem comprometer o meio ambiente e a rentabilidade da atividade agrícola. O objetivo deste trabalho foi estudar a ação de mecanismos sulcadores e a pressão da roda compactadora de uma semeadora-adubadora em plantio direto, na resistência de um Latossolo Vermelho distroférrico à penetração (RP), durante a semeadura da soja, sob três teores de água do solo. O experimento foi desenvolvido em esquema de blocos casualizados, arranjado em esquema de parcelas subsubdivididas, sendo as parcelas constituídas de três teores de água do solo (23,8; 25,5 e 27,5% b.s.), as subparcelas de dois mecanismos sulcadores (discos duplos e haste sulcadora) e as subsubparcelas de três pressões da roda compactadora (12,2; 18,5 e 24,1 kPa), com três repetições. O teor de água do solo promoveu diferença na RP com a profundidade, no leito de semeadura, independentemente do sulcador e da pressão da roda compactadora. O uso de haste sulcadora proporcionou menor RP comparada com o sulcador disco duplo, no leito de semeadura, independentemente do teor de água e da pressão da roda compactadora. A pressão aplicada pela roda compactadora de 18,5 kPa proporcionou as menores resistências do solo à penetração, quando a haste sulcadora foi usado. A RP foi menor na linha de semeadura do que na entrefileiras, até 20 cm de profundidade.

If inappropriately conducted, management and sowing practices may compromise the environment and the profitability of the agricultural activity. The aim of this study was to analyze the furrow opener mechanisms action and the level of load applied to soil firming mechanism in no-till, on the Oxisol resistance to penetration during soybean sowing, under three soil moistures. The experiment was arranged in split-split plot design, in which the plots were composed by three soil moistures (23.8; 25.5 and 27.5% b.s.), two furrow opener mechanisms sub-plots (double disks and furrow plough) and the split-split plot of three levels of load applied to soil firming mechanism (12.2; 18.5 and 24.1 kPa), according to randomized blocks design, with three replications. The soil moisture provided different resistance behavior to penetration with the depth, on the seedbed, independently of the furrow opener and the level of load applied to soil firming mechanism. The furrow plough use provided less soil resistance to penetration when compared to the double disk furrow opener, on the seedbed, independently of the soil moisture and the level of load applied to soil firming mechanism. The pressure applied by soil firming mechanism of 18.5 kPa provided the lower resistance to penetration, when the furrow plough was used. The soil resistance to penetration was less on the sowing line than on between rows, with 20 cm deep.

As técnicas de colheita da cultura de cana nem sempre seguem preceitos conservacionistas, fato que pode influenciar atributos físicos do solo com consequente alteração da velocidade de infiltração de água no solo. O trabalho realizado teve como objetivo avaliar o efeito de diferentes sistemas de colheita (manual e mecanizada) da cana-de-açúcar (crua e queimada), sobre as características de infiltração e verificar a adequação de modelos matemáticos para a estimativa da taxa de infiltração de água no solo. Foi utilizado um simulador de chuva portátil calibrado para aplicar uma precipitação de 60 mm h-1. Os testes de infiltração de água no solo foram realizados em três sistemas de colheita: colheita manual de cana queimada, colheita mecanizada de cana crua e colheita mecanizada de cana queimada. A qualidade do ajuste dos modelos foi avaliada por meio de regressões não lineares entre os valores estimados e os valores médios observados em cada tratamento estudado. Nos tratamentos onde foi empregada a colheita mecânica, observou-se uma redução da taxa de infiltração final em relação à área sob colheita manual de cana queimada. A equação de Horton foi a mais adequada para a estimativa da taxa de infiltração de água no solo estudado.

The sugarcane harvesting techniques do not always follow the precepts of soil conservation, which may influence soil physical properties with consequent change in the rate of soil water infiltration. The study aimed to evaluate the effect of different cropping systems (manual cutting and automated cutting) of sugarcanes (green and burned), on water infiltration in the soil and to determine the adequacy of mathematical models to estimate the rate of water infiltration in the soil profile. It was used a portable rainfall simulator calibrated to apply rainfall of 60 mm h-1. Tests of water infiltration in the soil were carried out in three cropping systems: manual harvesting of burnt cane, mechanical harvest of green cane and mechanical harvesting of burnt cane. The quality of the adjustment of models was evaluated by non-linear regression between the estimated values and the mean observed for each treatment. In the treatment where mechanical harvesting was applied it was observed a decreasing in the final infiltration rate compared to the area under manual harvesting of burnt cane. The equation of Horton was the most suitable to estimate the water infiltration rate in soil.

Este trabalho teve por objetivo avaliar as qualidades física e fisiológica de sementes de feijão-carioca Iapar 81, colhidas em sistema semimecanizado, utilizando-se de colhedora autopropelida. Foi avaliada a influência da velocidade de deslocamento (6,5; 8,8; 10,2 e 10,8 km h-1), da rotação do cilindro trilhador (430 e 480 rpm) e do efeito latente dos danos mecânicos durante o armazenamento das sementes (0; 60; 120 e 180 dias). Foram determinados a impureza, o índice de danos mecânicos, o vigor e a germinação das sementes. O efeito latente dos danos mecânicos foi avaliado pelo teste de vigor, pela germinação e pela condutividade elétrica. Os menores valores de impureza foram obtidos nas velocidades de 10,2 e 10,8 km h-1 e na rotação do cilindro trilhador de 430 rpm, enquanto não houve efeito da velocidade quando foram usados 480 rpm no cilindro trilhador. Os maiores valores de dano mecânico visível, vigor e germinação foram obtidos nas velocidades de 8,8; 9,9 e 9,2 km h-1, respectivamente. O menor valor de condutividade elétrica da solução de embebição das sementes de feijão foi obtido na velocidade de 7,7 km h-1, independentemente da rotação do cilindro trilhador. Trabalhando com rotação de 480 rpm no cilindro trilhador, obtiveram-se os menores valores de percentagem de impurezas, vigor e germinação, e maiores valores de dano mecânico e condutividade elétrica. O período de armazenamento por 180 dias não provocou queda na germinação e no vigor.

The objective of this work was to analyze the physic and physiologic quality of bean seeds. The bean seeds variety was the Iapar 81. The system of harvesting used was the semi-mechanized. The seeds were harvested by a combine, model Axial Flow 2388. The quality analysis that considered the influence of four operation speeds (6.5; 8.8; 10.2 and 10.8 km h-1), two threshing cylinder velocity (430 and 480 rpm) and latent effect of mechanical damages during seeds storage (0; 60; 120 and 180 days) was studied. The impurity content, the mechanical damage, the electrical conductivity, the vigor and the seed germination were determined. The smallest values of impurity content were obtained in the displacement speeds of 10.2 and 10.8 km h-1, on the threshing cylinder velocity of 430 rpm, while there was not any effect of the speed when 480 rpm was used. The largest values of mechanical damage, vigor and germination were obtained in the displacement speeds of 8.8; 9.9 and 9.2 km h-1, respectively. The smallest value of electric conductivity was obtained in the speed of 7.7 km h-1, regardless of the threshing cylinder velocity. By working with 480 rpm on the threshing cylinder velocity it was obtained the smallest values impurities content, vigor and germination, and larger values of mechanical damage and electric conductivity. The seed vigor and germination did not decrease with the storage time of 180 days.

Este trabalho teve o objetivo de caracterizar sistemas de cultivo quanto à qualidade estrutural do solo para o desenvolvimento de plantas por meio da determinação do Intervalo Hídrico Ótimo (IHO). O estudo foi realizado com amostras indeformadas de um Latossolo Vermelho distroférrico, sob os sistemas de cultivo convencional, direto e integração lavoura-pecuária, no município de Dourados - MS. Em cada sistema de cultivo, foram amostrados 28 pontos, nas camadas de 0-0,05 m, 0,05-0,10 m, e 0,10-0,20 m, totalizando 84 amostras por sistema, que foram utilizadas para a determinação da curva de retenção de água no solo, da curva de resistência do solo à penetração e da porosidade. No sistema de cultivo convencional e no direto, a menor limitação ao desenvolvimento radicular foi na camada de 0-0,05 m, e na integração, a limitação foi menor na camada de 0,10-0,20 m. Na camada de 0-0,05 m do convencional, o IHO foi igual à capacidade de água disponível. Nos sistemas direto e integração, a resistência à penetração foi limitante. A resistência à penetração foi o principal fator limitante do IHO na maioria das situações estudadas.

The objective of this work was to characterize the growing systems related to the structural soil quality for plants development by the Least Limiting Water Range (LLWR). The study was developed using soil samples with preserved structure of a Distroferric Red Latossol under the conventional, no tillage and integrated growing systems in de county of Dourados-MS, Brazil. In each system 28 points were sampled, in 0-0.05, 0.05-0.10 and 0.10-0.20 m deep layers, ending up with 84 samples by system which was used to adjust the water retention curve in the soil, soil resistance to penetration curve and porosity determination, all of them necessary to the LLWR determination. In the conventional and no-tillage systems the smallest restriction to de roots development was in the 0-0.05 m layer, while in the integration system the smallest limiting was in 0.10-0.20 m layer. In the conventional system, in the 0-0.05 m layer, the LLWR was equal to the available water capacity, in the direct and integrated systems the resistance to penetration was the limiting factor. The resistance to penetration was the major limiting factor in most of the studied situations.

Neste estudo, desenvolveu-se um modelo de simulação para analisar a dinâmica de um sistema a fim de controlar automaticamente a altura de corte em colhedoras. Este modelo foi implementado com base nas equações diferenciais, que descrevem a dinâmica da plataforma de corte, o comportamento do sistema hidráulico e o controlador. O sistema de controle realimentado simulado foi constituído de uma célula de carga, destinada a medir a força de contato entre o solo e o mecanismo de corte, um controlador PID e um sistema hidráulico de atuação, composto de uma válvula proporcional direcional de quatro vias e um atuador. Analisou-se a influência da velocidade de deslocamento da máquina (1,0, 1,5 e 2,0 m s-1), da pressão de suprimento do sistema hidráulico (6,8, 13,7 e 20,6 MPa), da massa da plataforma (40, 60 e 80 kg) e da força de contato de referência do controlador (200, 400 e 800 N) no desempenho do sistema de controle. Os aumentos na pressão de suprimento, massa da plataforma e força de referência, proporcionaram melhores condições para o funcionamento do sistema de controle proposto.

A simulation model to analyze the dynamics of a system to control automatically the cutting height in harvesters was developed. The model was developed using the differential equations that describe the dynamics of the cuttig platform, the behavior of the hydraulic system and the controller. The simulated feedback control system was composed by a load cell that measures the contact force between the soil and the cutting device, a feedback controller (PID) and a hydraulic system with proportional directional four-way valve and actuator. The effect of the following variables in the controller performance was analyzed: speed of the cutting device (1.0, 1.5 and 2.0 m s-1); pressure in the supply line of the hydraulic system (6.8, 13.7 and 20.6 MPa); ballast added in the cutting mechanism (40, 60 and 80 kg) and the contact force between the cutting device and the soil (200, 400 and 800 N). The developed model showed to be a useful tool for analyzing the dynamics of the controller. The increase in the supply pressure, mass of the cut platform and reference force provided better performance of the control system.

Este trabalho avaliou o desempenho de uma derriçadora portátil para cafeicultura de montanha durante a colheita de frutos de cafeeiros Catucaí e Catuaí, em vários estádios de desenvolvimento. Foram determinados as características dos cafeeiros, as curvas características do motor da derriçadora, a capacidade e a eficiência de derriça, o consumo de energia, a desfolha e o nível de ruído emitido pela máquina. A derriçadora portátil teve desempenho satisfatório por apresentar baixa desfolha e número de galhos quebrados, capacidade de derriça regular, baixo consumo específico de energia e elevada eficiência de derriça. O nível de ruído aumentou com o aumento da potência requerida na derriça.

The portable harvester performance was evaluated for mountain coffee during the detachment of the fruits in different ages of the plants. The performance evaluation of the portable harvester was accomplished with four ages of plants and two coffee varieties. The coffee plant characteristics, the curve characteristics of the portable harvester engine, the detachment capacity and efficiency, the specific energy consumption, the mechanical damage and the noise level emitted by the machine were evaluated. The portable harvester held out a satisfactory performance by presenting less mechanical damage and number of broken branches, a regular detachment capacity, low specific energy consumption and high detachment efficiency. The noise level increased with the increasing of the power requirement.

Estudou-se o desempenho operacional de dois equipamentos na colheita da mandioca. Um afofador do solo e um arrancador de mandioca foram avaliados. Analisaram-se a patinagem das rodas motoras, as perdas de produto, os danos mecânicos provocados às raízes e a capacidade de campo dos conjuntos trator-equipamento. Depois da passagem dos conjuntos, as raízes inteiras colhidas e que permaneceram no solo e com danos mecânicos, foram separadas e pesadas. O conjunto trator-arrancador apresentou melhor dinâmica de corte, penetração no solo e menor patinagem das rodas. Não foram observadas perdas de raízes para os conjuntos avaliados. Os equipamentos apresentaram semelhantes danos mecânicos às raízes. O conjunto trator-afofador apresentou capacidade de campo 25% superior ao conjunto trator-arrancador. Entretanto, como o conjunto trator-afofador não deixa as raízes expostas e não possui dispositivo de corte frontal da parte aérea das plantas, foi observado aumento de 32% no tempo necessário para as operações de corte e separação das raízes. O desempenho operacional do conjunto trator-arrancador foi superior ao conjunto trator-afofador.

The operational performance of two equipments for the cassava harvest was studied. A soil disaggregating implement and an up root implement were evaluated. The wheel slip, the losses, the mechanical damage caused in roots and the field capacity of the tractor-implement systems were analyzed. In each test, the whole roots and the roots with mechanical damages were separated and their mass were obtained. Tractor-up root system showed the best dynamic of cut and soil penetration, which was considered the smallest wheel slip. No root losses were observed for the two systems. Between implements there was not difference for mechanical damages caused in roots. The tractor-disaggregating implement system presented field capacity of 25% upper than tractor-up root system. However, as tractor-disaggregating implement system did not leave roots exposed and it did not have a frontal device of plant pruning, it was observed an increase of 32% on necessary time for cutting and roots separation. The tractor-up root system provided higher operational performance.