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 Although peanut harvesting results in significant losses, it has rarely been investigated. Thus, this study aimed to analyze the interference of different pod moisture contents on peanut harvesting and their influence on the process quality based on losses and impurities. An experiment was performed in a peanut seed producing area, in Luzitânia, district of Jaboticabal - SP, using average moisture contents of 15% and 20% in the pods; 16 and 14 data points were collected for the 20% and 15% treatments, respectively. The experimental design used statistical process control (SPC) to analyze the collected variables. The results indicated higher losses in the platform than in the machine. In addition, the harvest quality was not affected by the pod moisture content. However, the correct adjustment of machines can restrict total losses to approximately 1% of the yield. Pods with moisture contents of 15% and 20% can be used for peanut harvesting. However, although a pod moisture content of 15% reduced the amount of mineral and vegetal impurities inside the bulk tank, the number of open pods increased, whereas a pod moisture content of 20% provided a greater number of whole pods.

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.

RESUMO Os erros de posicionamento pelo GNSS são inevitáveis, independentemente do tipo de posicionamento adotado. Na agricultura esses erros podem representar maior ou menor taxa de sobreposição entre as passadas dos conjuntos mecanizados, o que afeta, consequentemente, a qualidade da operação. Objetivou-se, neste sentido, avaliar os principais erros ocasionados durante a operação de semeadura de amendoim utilizando direcionamento automático com sinal RTX, por meio da análise do Controle Estatístico de Processo. Foram avaliados o erro de deslocamento do trator, o erro de execução do projeto, em quatro passadas, além do erro de paralelismo entre as passadas do conjunto trator-semeadora. O erro médio de execução ficou, em todas as passadas, dentro do estipulado pelo fornecedor do sinal, com valores menores que 3,8 cm. O erro médio do conjunto trator-semeadora encontrou-se no limite do aceitável. Já para o deslocamento lateral do trator, pela análise das cartas de controle, houve interferência da declividade na ocorrência de erros acima do estipulado. Com base na análise das cartas de controle constata-se que houve precisão para o erro de execução de projeto e que é possível utilizar o sinal RTX em operações agrícolas que requerem precisão menor que 3,8 cm, como a semeadura de amendoim.

ABSTRACT GNSS positioning errors are certain, regardless of the adopted positioning method. In agriculture, these errors may represent higher or lower overlapping rates between passes of a mechanical assembly, affecting operation quality. Therefore, this study evaluated the main errors arising from peanut sowing operation performed with an auto-steer guidance system by an RTX signal, using the Statistical Process Control techniques. The errors evaluated were: in tractor lateral displacement, project execution, and parallelism between passes of tractor-seeder set. The average errors of project execution in all passes were within the range specified by the manufacturer, i.e. lower than 3.8 cm. The average error of tractor-seeder set was also within the accepted range. However, as shown in control charts, lateral tractor displacement had interference of terrain slope, causing average errors higher than the accepted range. Based on the control charts, project execution accuracy was satisfactory, and it is possible to use the RTX signal in agricultural operations that require accuracy lower than 3.8 cm, such as peanut sowing.

ABSTRACT The digging of peanut, which has the pod production in the subsurface, is directly affected by soil conditions, physical or environmental characteristics, at the time of operation and may be the cause of unwanted losses. Therefore, the quality of the operation is very important for minimizing these losses. Thus, this study aimed to evaluate the quality of mechanized digging operation of peanut according to three soil textural classes (Sandy, Medium and Loamy) and their water content conditions at operation through statistical process control. The experiment was conducted at three locations in the state of São Paulo, Brazil, under sampling scheme arranged in tracks and 40 sampling points for each textural class of soil, using the mechanical digging variables as indicators of quality. We found that the mechanized digging operation in Sandy soil was the most critical, just meeting the specifications of quality indicators, reflecting higher losses and lower quality of the operation. Medium soil showed at the digging good and homogeneous conditions in relation to water content in soil and pods, and because it has favorable characteristics it obtained the lower total losses and higher quality of operation. Loamy soil showed satisfactory quality, meeting the specifications as well, but with poorer quality than the Medium Soil.

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.