Coffee Science - v.13, n.1, 2018

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10542

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Characterization of the coffee fruit detachment force in crop subjected to mechanized harvesting
(Editora UFLA, 2018-01) Ferreira Júnior, Luiz de Gonzaga; Silva, Fábio Moreira da; Ferreira, Danton Diego; Simão, Sérgio Domingos; Souza, Gabrielly Carvalho de; Ferreira, Lucas Kemps
In order to adjust the coffee harvester and to assist in deciding either whether or not to make a second pass of the harvester, fully or selectively, it is necessary to know some crop parameters. The aim of the present study was to evaluate the coffee fruit detachment force in the green and cherry ripeness, under different plant positions and in four evaluation periods, throughout the harvest period between the first and second pass of harvester. The cultivar used was the Catuaí Amarelo IAC 144 aged eight years in spacing 3.8 x 0.9 m. Detachment force was determined by sampling using a portable digital dynamometer. The green ripeness stage showed superior detachment force than the cherry for all evaluation periods. The fruit detachment force for the green and cherry ripeness showed a decreasing behavior during the evaluation period, since the difference between the detachment forces of these fruits increased, thus guiding the type of harvest to be performed. Beyond the fruit detachment force difference, other parameters such as fruit ripening rate and crop load were essential for harvest management. Significant variations were identified in the fruit detachment force positioned in different parts of the coffee tree branches. The results also reinforce the relevance of characterizing the coffee fruit detachment force for harvester adjustments and management of the selective mechanized harvesting.
Performance of a special tractor as a function of ballasting and front-wheel drive in coffee harvesting
(Editora UFLA, 2018-01) Tavares, Tiago de Oliveira; Borba, Matheus Anaan de Paula; Gallo, Luís Alexandre Michelli; Gírio, Lucas Augusto da Silva; Paixão, Carla Segatto Strini; Silva, Rouverson Pereira da
One of the main concerns before agricultural mechanization is the fuel cost from an economic and environmental point of view. In some literature, it has been demonstrated that the adequacy of tractors is directly related to consumption, which may become a strategy to reduce it. However, the studies were performed with conventional tractors, without information on how the special coffee tractors behave to the adequacy. In this respect, the aim of the present study was to evaluate the hourly fuel consumption in six possible adjustments of a special tractor in the operation of mechanized coffee harvesting. A 4x2 FWD tractor was used, with 52.2 kW power and 2400 kg mass, with 40% to the front axle and 60% to the rear to pull a Master Café 2 coffee harvester with 2900 kg mass without load. The treatments consisted of three ballast configurations in the tractor whether or not using auxiliary front-wheel drive (FWD). The adopted mass-power ratios were: 48, 52 and 56 kg kW-1 ; obtained through the quantitative alteration of liquid and solid ballasts of the tractor, respecting the mass distribution between the axles recommended by the tractor manufacturer. The evaluations consisted of monitoring fuel consumption at regular hourly intervals, following the premises of statistical process control. It is concluded that the mass-power ratio of 56 kg kW-1 with driven FWD should be used in order to obtain lower slipping, lower average hourly fuel consumption and higher quality.