ABSTRACT Statistical process control has been widely used in agricultural operations for monitoring and improving process quality. This study aims to evaluate the Shewhart and exponentially weighted moving average (EWMA) control charts to monitor the performance of an agricultural tractor–planter set. The design is completely randomized based on the assumptions of statistical process control and comprises two treatments: day and night shift treatments. The data to assess the performance of the tractor–planter set are collected during the day and night shifts and used to evaluate the operating speed, motor rotation, engine oil pressure and water temperature, and hourly fuel consumption. The dataset comprised 40 samples compiled from the frontal monitor column inside a tractor cab. It is concluded that both Shewhart and MMEP/EWMA control charts can be used to evaluate engine performance based on the quality indicator parameters investigated, regardless of the normality assumption of the datasets.

ABSTRACT Sugarcane mechanized harvesting can lead to serious risks to the longevity of plantations when improperly operated, and may cause damages and disturbances in the remaining ratoons in the field. In this sense, this study aimed to evaluate the damage and disturbance to the sugarcane ratoons by the base cutting quality of two-blade models through statistical process control. The experiment was carried out during the 2015/16 growing season in an agricultural area of the Moreno Mill, located in Cravinhos, São Paulo, Brazil. The sugarcane harvester models A8800 (Machine 1) and BE1035 (Machine 2). The sugarcane variety cultivated in both treatments was SP80-1816. Thirty points were sampled per harvester, with 10-minute intervals between them. Equations were used to calculate the indices, which were then evaluated through descriptive analysis and statistical process control. Machine 2 presented process instability for the index of damages, with lower data variability. On the other hand, Machine 1 presented instability during the process due to the quality indicator and index of disturbance, but with a lower operation variability.

ABSTRACT The mechanized sugarcane harvesting process is considered one of the major economic bottlenecks, with low operational efficiency and, mainly, high losses of stalks left in the field. In order to minimize these problems and assist in the improvement of processes, this study aimed to evaluate the losses in the mechanized sugarcane harvesting using statistical process control. The experimental design was completely randomized, based on the methodology of statistical process control with samples collected on five work fronts during the daytime and nighttime operation. The experiment was carried out in an agricultural area of a sugarcane mill in the municipality of Ribeirão Preto, SP, Brazil, on five sugarcane harvest fronts. Losses were measured using a 3.0 × 3.33-m frame, being divided into stump, loose piece + fixed piece, whole sugarcane, fragment, and total losses for each harvest front. The data were grouped into 50 weeks over the sugarcane-growing season, and statistical analyses were performed using the Minitab 16® software. Losses of loose piece + fixed piece were higher than the losses of stump, whole sugarcane, and fragment. The total losses showed higher and lower losses for the fronts F5 and F4, respectively, compared to the others.

ABSTRACT The mechanized harvesting of sugarcane has increased exponentially in recent years because of the gradual prohibition of burning on the cane fields in mechanizable and non-mechanizable areas. This study aimed to evaluate the wear of the basal cutting knives in two different mechanized sugarcane harvesters, through statistical process control. The experiment was conducted in Cravinhos, São Paulo, in an agricultural area, on July 25, 26, and 27, 2016. Two harvesters with different basal cutting mechanisms were evaluated: harvester A—Model BE1035e (conventional type knife), and harvester B—Model A8800 (racket type knife). The experimental design was completely randomized with two treatments. The wear was quantified by measuring the thickness increase and width losses of each knife, and it was evaluated for each harvester every 2 hours, during 3 days of operation. Data were evaluated using descriptive statistics and statistical process control. The harvester B model (racket knife) presented lower variability in the cutting width and stability in the cutting width of the knives. The harvester A model (conventional knife) presented greater wear in the width, but less variability in the thickness of the cutting wire.

ABSTRACT The use of automatic routing significantly increases the yield and quality of agricultural operations and reduces the overlap rates between the mechanized set passes during the operation. The objective of this study was to analyse the quality of peanut sowing using automatic routing in two paths, curved and rectilinear, based on the error of parallelism and execution error, through statistical process control. The maps used came from an area of peanut seed production, in the city of Luzitânia, São Paulo, Brazil. The sowing was carried out by the execution of a project elaborated in CAD software that, for its elaboration, was taken into consideration the working width of the seeder-fertilizer, as well as the spacing of the crop. The CenterPoint RTX signal was used on both routes. The errors were measured in the Agrocad® program, by means of the orthogonal difference between the lines, and the execution errors were calculated based on the difference between the previously projected lines and the lines executed by the tractor. In general, the sowing operation presented better quality in the rectilinear path, providing smaller parallelism and execution errors. The maximum errors of parallelism were 8.75 and 5.22 cm in the curved and rectilinear path, respectively. The RTX signal ensured good quality of operation in rectilinear path, with low probability of errors occurrence above 3.8 cm.

ABSTRACT The quality control is used for the evaluation of processes and products, and it is important to detect and reduce variability and in operations management can be applied in mechanized harvesting of sugarcane billets. In this sense, this study aimed to identify critical quality indicators and, if necessary, to develop a continuous improvement plan for harvest of sugarcane billets. For the survey and definition of critical quality indicators the FMEA (Failure Mode and Effect Analysis) was applied, after the formation of the quality technical team. Evaluations of the collected variables were through control charts of individual values and the process capability indexes. There are 8 critical quality indicators in the billets harvesting process; the cutting height, the damage index, the percentage of non-viable buds and operating speed have greater importance for analysis due to the risk priority index and the easiness of obtaining data for analysis. The development of the improvement plan aims to reduce the variability due to crop billets, thus, making it able to perform the operation within the required quality standards.

ABSTRACT: The intensive mechanization during the harvest operation and success of this operation depends on several factors, one of which is the length and format of the plots. The aim of this study was to evaluate the operating performance of a soybean harvester in different geometric plots shape, using as quality indicators performance parameters by means of statistical control tools of process. The experiment was conducted in March 2014 in the city of Uberaba - MG. Operational capacity was evaluated in the mechanical harvesting of soybeans in three plots: irregular, rectangular and trapezoidal. Performance evaluations of soybean harvester were made from the following parameters: displacement speed, engine rotation, cylinder rotation and concave opening. The grain water contents affect the quality indicators of the soybean harvester performance in all plots shapes. The harvester performance is considered able to maintain between the specification limits and close to the target, to speed quality indicators the irregular and the trapezoidal plots and for cylinder rotation the trapezoidal plot.

ABSTRACT: Information on harvester performance is important in the management and optimization of mechanized agricultural systems. In this sense, the aim of this study was to monitor the operation quality of soybean mechanical harvesting in different plot shapes by means of statistical process control. The harvest was carried out in an agricultural area of a farm located in Uberaba, MG, Brazil, with an experimental design based on the assumptions of statistical quality control and 18, 28, and 24 replications for irregular, rectangular, and trapezoidal plots, respectively. The variables and/or quality indicators of harvester performance were forward speed, engine speed, cylinder speed, and concave opening. The lowest variation occurred in the irregular plot for the quality indicators forward speed and engine speed of harvester. Engine speed and the concave opening of harvester were unstable for all plot shapes. Only the cylinder speed of the soybean harvester presented process stability during operation for the three plot shapes.

RESUMO A colheita mecanizada de soja é fundamental no processo produtivo desta cultura e, caso não seja realizada adequadamente, poderá resultar em danos mecânicos severos às sementes, acarretando prejuízos significativos na colheita, particularmente devido à redução da qualidade. Neste sentido se objetivou, neste trabalho, avaliar a qualidade física e fisiológica das sementes de soja em três velocidades da colhedora, por meio do controle estatístico de processo. O experimento foi realizado em área agrícola, no município de Conceição das Alagoas, MG, com três velocidades de deslocamento da colhedora (4,5; 5,0 e 5,5 km h-1). As amostras de sementes foram coletadas em intervalos de 20 min durante 3 h de operação, totalizando nove amostras para cada velocidade. As avaliações foram realizadas a partir dos seguintes parâmetros: temperatura das sementes, teor de água, abertura do côncavo, rotação do cilindro, danos mecânicos e condutividade elétrica. A qualidade física e fisiológica das sementes foi influenciada pela velocidade de deslocamento da máquina. A maior velocidade apresentou menor valor de dano mecânico e maior vigor das sementes de soja.

ABSTRACT The mechanized harvesting of soybean is a fundamental tool in the production process of this crop and, if not performed properly, it can result in severe mechanical damage to the seeds, causing significant losses at harvest, particularly due to reduced quality. Thus, this study aimed to evaluate the physical and physiological quality of soybean seeds at three speeds of the harvester, using statistical process control. The experiment was carried out in the municipality of Conceição das Alagoas, MG, Brazil, with three travel speeds: 4.5, 5.0 and 5.5 km h-1. The seed samples were collected at 20 min intervals for 3 h of operation, with a total of 9 samples for each speed. The evaluations were performed based on the following parameters: grain temperature, water content, concave opening, cylinder rotation, mechanical damage and electrical conductivity. The physical and physiological quality of the seeds was dependent on the displacement speed of machine. The highest speed led to lower mechanical damage and higher vigor of soybean seeds.

ABSTRACT The knowledge of the operational quality of soybean harvester provides useful information to management in order to obtain the maximum performance of all available resources, with minimal expenses. The aimed of this study was to evaluate the quality of mechanized soybean harvesting operation in different formats of plots through statistical process control. Treatments were established from the formats of existing plots in the area (irregular, trapezoidal and rectangular). The activities carried out during the harvest were monitored (harvesting, unloading, handling, maneuvering and climate charts) and through these activities were made the calculation of capacity and harvesting operation efficiencies. In the determination of total losses were used 4 circular frames of 0.33 m2 each, the grain losses were considered below and above these frames. The statistical analysis was by means of statistical process control opting for the use of the type CUSUM charts. The rectangular plot showed greater management efficiency and harvesting efficiency. The trapezoidal shape facilitated the maneuvers relative to others. The rectangular plot has better quality of operation in relation to others. The CUSUM control chart showed to be effective in preventing instability and maintenance of process quality.

RESUMO O controle estatístico de processo aplicado em operações agrícolas mecanizadas representa uma nova maneira de avaliar a qualidade com que as operações são realizadas. Neste sentido, objetivou-se neste trabalho comparar três tipos de ferramentas do controle estatístico de processo aplicadas às perdas na colheita mecanizada de cana-de-açúcar, para determinar qual o melhor modelo de carta de controle a ser utilizado para este indicador de qualidade. O monitoramento das perdas na colheita mecanizada foi realizado diariamente nas áreas agrícolas, de uma unidade produtora na região do Triângulo Mineiro - MG, durante o período de 70 dias, na safra de 2014. Ao final do período de avaliação, foram coletados 194 pontos amostrais no total, para cada tipo de perda analisado. As cartas de controle utilizadas foram: carta de valores individuais, média móvel e média móvel exponencialmente ponderada. Os indicadores de qualidade avaliados durante a colheita de cana-de-açúcar foram as perdas do tipo: rebolo inteiro, tocos, pedaço fixo, cana inteira, lascas, pedaços soltos e totais. A carta de controle de valores individuais é a melhor opção para o monitoramento das perdas na colheita mecanizada de cana-de-açúcar, por apresentar maior facilidade na interpretação dos resultados, em relação às demais.

ABSTRACT Statistical process control in mechanized farming is a new way to assess operation quality. In this sense, we aimed to compare three statistical process control tools applied to losses in sugarcane mechanical harvesting to determine the best control chart template for this quality indicator. Losses were daily monitored in farms located within Triângulo Mineiro region, in Minas Gerais state, Brazil. They were carried over a period of 70 days in the 2014 harvest. At the end of the evaluation period, 194 samples were collected in total for each type of loss. The control charts used were individual values chart, moving average and exponentially weighted moving average. The quality indicators assessed during sugarcane harvest were the following loss types: full grinding wheel, stumps, fixed piece, whole cane, chips, loose piece and total losses. The control chart of individual values is the best option for monitoring losses in sugarcane mechanical harvesting, as it is of easier result interpretation, in comparison to the others.