The correct choice of modern power transmissions can help farmers decrease production costs. The following research aimed to assess fuel consumption efficiency of an agricultural tractor equipped with continuously variable transmission, at different travel speed and load levels applied on the tractor drawbar. Standard procedure has been applied considering six load levels (30; 40; 50; 60; 70 and 80% of Q0) by means of breaking with a dynamometer car instrumented in a concrete test track, at three travel speeds (5.16; 7.29 and 10.48km h-1). Throughout the experiment, engine speed, traction force and hourly fuel consumption were monitored. The results indicated that there was an average increase of 2.67; 2.82; and 2.61L h-1 in the hourly fuel consumption for each 10% increase in the load level on the tractor, for travel speed of 5.16; 7.29 and 10.48km h-1, respectively. In general, the specific fuel consumption of the tractor decreased as the load levels and the travel speeds were increased.

Considering the need to reduce environmental contamination and uplift the effectiveness and quality of pesticide application, this work had the goal to determine the conditions of use and conservation of agricultural sprayers used in the Central and Western border of the state of Rio Grande do Sul, and to identify the most frequent problems in agricultural sprayers. Fifty-six sprayers connected to a three-point hydraulic system and the tractor drawbar were inspected, evaluating the safety and operation items using the methodology described in the Standard ISO 16122. After the evaluations, the collected data were submitted to an exploratory analysis by using descriptive statistics with the use of percentage frequency. Based on the obtained results, it is possible to observe that the most serious problems are mainly related to the safety of the operator and the environment, since 41.07% of the sprayers did not have the protection of the cardan transmission and 33.93% did not have the protection of straps and pulleys. In addition, static leaks were present in 46.43% of the samples and 87.50% presented dynamic leaks. In 71.43% of the cases, there was no presence of a clean water reservoir to wash the rigid packagings. Therefore, it is possible to conclude that the state of use and conservation of the inspected sprayers is serious, justifying the need for inspections on agricultural sprayers to become mandatory in Brazil, also requiring government policies for the renewal of these equipments, as well as, the homologation of research centers to conduct tests on agricultural machinery and implements before their commercialization. In addition is also necessary to invest in training of operators by conducting technical courses about the importance of equipment knowledge, available technologies and necessary maintenance, as the level of knowledge is low about the basics of operational safety, maintenance and use of the sprayers which contributes to the high percentages of nonconformity with ISO 16122.

RESUMO Nos últimos anos, a oferta de pulverizadores autopropelidos no mercado brasileiro aumentou, principalmente para suprir a demanda de agricultores que possuem grandes extensões de áreas, nas quaisOs pulverizadores são utilizados para aplicar agrotóxicos e fazer com que estes produtos atinjam o alvo desejado. No mercado brasileiro, existem diversos tipos, desde os mais simples, do tipo costal, utilizados para atender pequenas áreas, até os pulverizadores autopropelidos, os quais possuem alta tecnologia e elevada capacidade operacional, capazes de atender grandes áreas com qualidade na pulverização (CASALI et al., 2011).A escolha da máquina e sua correta utilização são fatores fundamentais para se obter qualidade na aplicação e eficiência dos agrotóxicos. Para se obter qualidade nas aplicações, deve-se possuir o maior conhecimento sobre quatro fatores: máquina agrícola, alvo biológico, fatores climáticos e agrotóxicos (SCHLOSSER, 2002).O motor e a transmissão tornam os pulverizadores autopropelidos autônomos na sua operação. Para o deslocamento da máquina e o acionamento de mecanismos internos do circuito hidráulico, utiliza-se a potência do motor, declarada pelos fabricantes e conhecida como potência nominal, conforme a norma ABNT NBR ISO 3046/1 (1995).Muitos fatores associados com os pulverizadores tratorizados determinam a eficiência operacional do trabalho, destacando-se: velocidade, tamanho da barra, tempo de manobra, capacidade do reservatório de calda, tempo de reabastecimento e distância percorrida (MATUO, 1990). Além desses, perfeitamente aplicáveis aos pulverizadores autopropelidos, o sistema -NOTA -I Programa de Pós-graduação em Engenharia Agrícola

This study aimed to develop and validate an ergonomics index for the operator workplace assessment of agricultural tractors sold in the Brazilian market. To develop the ergonomics index, the operator work places were assessed for compliance with current, national and international, safety and ergonomics standards. The following standards were analyzed to develop ergonomics index: ISO 15077 (1996), which regulates the position of operator controls; ABNT NBR ISO 4254-1(2015) and ABNT NBR ISO 4252 (2011), which regulate the access to operator workplaces; and NR 12 (2010), which determines the mandatory items of operator workplaces.Thirty-four operator work places of 152 models of new agricultural tractors sold in the Brazilian market were analyzed in this study. Ergonomics index was developed and validated using these standards, and the findings enabled the ranking of agricultural tractors. Therefore, the proposed ergonomics index proved feasible and may be applied to other agricultural machines.

The periodic maintenance of agricultural sprayers is essential to ensure safe spraying from an environmental point of view and technically efficient, with respect to acceptable quality limits. Aiming to optimize the use of pesticides for protecting farming, many countries worldwide have been developing projects on the inspection of agricultural sprayers. In Brazil, regardless its tradition of being an agricultural country, still now these inspections are done in a voluntary way, showing that most agricultural sprayers are not in use conditions, which can affect the technical efficiency of the operation, offer a risk of environmental contamination and, intoxication of the operator. This review aim describe the results got through projects on inspection of agricultural sprayers in different Brazilian regions. The methodology was based on the survey of data published in scientific articles and thesis. The most serious problems detected in those agricultural sprayers are mainly in terms of absence of environmental and user safety, no protection of the cardan tree, of belts and pulleys as well as leakage occurrence. Furthermore, the most common problems related to spraying activities are those of manometer precision as well as those of worn spray nozzles and spray transverse distribution wear and tear that in all justifies the obligation for technical inspection of agricultural sprayers in Brazil. Besides that, it is important to emphasize the necessity of public policies for development and approval of research centers for tests on agricultural implements.