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.

A colheita mecanizada de cana-de-açúcar é uma tendência crescente e irreversível ao setor canavieiro, devido à sua maior operacionalidade durante os turnos diurno e noturno, em razão das leis ambientais e trabalhistas ligadas a esta operação. Entretanto, o grande desafio deste sistema é a melhoria do mecanismo de corte de base, uma vez que esse mecanismo é capaz de causar elevados índices de danos e abalos nas soqueiras quando associado ao desgaste das facas do mecanismo de corte basal. Diante do exposto, objetivou-se, neste trabalho, avaliar a qualidade do corte basal por meio dos índices de danos e abalos causados às soqueiras, bem como o desgaste de três modelos de facas do mecanismo de corte basal de cana-de-açúcar, em função do tempo de uso. O delineamento estatístico utilizado foi o inteiramente casualizado, utilizando-se de três malhas amostrais, com espaçamentos de 50,0 x 1,50 m entre si, para cada modelo de faca, em diferentes glebas no mesmo talhão e repetições. As avaliações realizadas foram: perda de massa, desgaste do comprimento, largura e espessura do fio de corte das facas, bem como altura de corte, índice de danos e de abalos às soqueiras. A qualidade do corte basal é afetada pelo modelo de faca utilizado e pelo tempo de uso. A faca B apresenta menor variação e maior qualidade do corte basal para os índices de danos e de abalos às soqueiras de cana-de-açúcar.

Sugarcane mechanized harvesting is a growing and irreversible trend towards sugarcane industry because of the increased workability during night and day shifts besides requirements of environmental and labor laws related to this operation. However, a major challenge is to improve basal cutting mechanism, since it may increase sugarcane stool damages and jolts combined with knife wear. Given the above, we aimed to evaluate basal cut quality through damage and jolt indexes in sugarcane stool, as well as wear of three knife models that are used in basal cut mechanism along run time. The experimental design was completely randomized, using three sample meshes with spacing of 50.0 x 1.50 m for each knife type at different plots over the same field stand with replications. We assessed weight loss, wear length, width and thickness of the cutting knives and cutting height, stool damage and jolt rates. It was found that basal cut quality is affected by knife model and run time. The knife B showed less variation and higher cut quality for damage and jolt rates in sugarcane stool.

As maiores perdas na colheita mecanizada ocorrem na operação do arranquio sendo que sua avaliação ainda é incipiente no Brasil. Objetivou-se, portanto, neste trabalho, avaliar as perdas quantitativas e o desempenho do conjunto trator-arrancador-invertedor em função de teores de água do solo e populações de plantas. O experimento foi conduzido em delineamento experimental em blocos casualizados com esquema fatorial 2 x 3 em que os tratamentos foram constituídos de dois teores de água no solo (19,3 e 24,8%) e três populações de plantas (86.111, 127.603 e 141.144 plantas ha-1), com quatro repetições. Avaliaram-se as perdas quantitativas no arranquio e o desempenho do conjunto mecanizado. A maior quantidade de perdas visíveis e totais foi encontrada na população de 141.144 plantas ha-1 para o teor de água do solo de 19,3%. O fluxo de material colhido e o desempenho do conjunto trator-arrancador-invertedor não foram influenciados pelos teores de água do solo e populações de plantas. O teor de água das vagens foi maior no teor de água do solo de 24,8% somente para a população de 86.111 plantas ha-1; a produtividade foi maior nas populações de 141.144 e 127.603, nos teores de água de 19,3 e 24,8%, respectivamente.

The largest losses in mechanical harvesting of peanuts occur during the stage of digging, and its assessment is still incipient in Brazil. Therefore, the aim of this study was to evaluate the quantitative losses and the performance of the tractor-digger-inverter, according to soil water content and plant populations. The experiment was conducted in a completely randomized block design with a factorial scheme 2 x 3, in which the treatments consisted of two soil, water content (19.3 and 24.8%) and three populations of plants (86,111, 127,603 and 141,144 plants ha-1), with four replications. The quantitative digging losses and the set mechanized performance were evaluated. The largest amount of visible and total losses was found in the population of 141.144 plants ha-1 for the 19.3% soil water content. The harvested material flow and the tractor-digger-inverter performance were not influenced by soil water content and plant population. The water content in the pods was higher in 24.8% soil water content only for the population of 86,111 plants ha-1; the yield was higher in the populations of 141.144 and 127.603 plants ha-1, in the 19.3 e 24.8% soil water content, respectively.