No abstract

No abstract

Recebido em setembro/2014; Aceito em fevereiro/2015. RESUMO:Considerando a importância da cultura da soja para o estado de Mato Grosso, em especial a região Médio-Norte e a carência de dados relacionados às perdas oriundas da colheita mecanizada, foi conduzido um levantamento do nível de perdas na colheita mecanizada de soja durante a safra de 2012/2013. Foram visitadas 12 fazendas em sete municípios da região Médio-Norte, nos quais foram avaliadas 16 máquinas colhedoras por meio da metodologia do gabarito. Em geral, aproximadamente, 69% das colhedoras avaliadas apresentaram nível aceitável de perdas (até 60 kg ha -1 ). Considerando-se as colhedoras que se encontravam em condições adequadas de trabalho a perda total média foi de 57 kg ha -1 . Em alguns casos foram encontradas colhedoras com perdas menores que 40 kg ha -1 (25 % da frota) e até com perdas menores que 20 kg ha -1 , indicando que o nível de perdas da região ainda pode ser reduzido. Obviamente, em condições de cultura, terreno e clima favorável. A maior parte da frota de colhedoras da região estava trabalhando dentro dos níveis aceitáveis e situações de perdas acima do tolerável foram identificadas em máquinas com sérias evidências de manutenção precária. Palavra-chave: Desempenho, Colhedoras, Produção de Grãos. ABSTRACT:Considering the importance of the soybean crop for the state of Mato Grosso, in particular the Mid-North region, and the lack of data regarding losses due to mechanized harvesting, a survey was conducted in the region during the season of 2012/2013. Twelve farms were visited in seven municipalities in the Mid-North region yielding in 16 harvesters evaluated. Results indicated that approximately 69% of the assessed harvesters were working within the acceptable level of losses (60 kg ha -1 ), and considering the harvesters that were found in proper working conditions, the average total loss found in the study was 57 kg ha -1 . It can be concluded that the most part of the machines that composes the fleet, were working within acceptable losses levels, and also, extreme situations of losses could be identified on machines presenting evidences of poor maintenance. Although majority of the machines presented acceptable performance regarding losses, combines with losses lower than 40 kg ha -1 (25% of the fleet) were found, and even specific condition with losses less than 20 kg ha -1 , indicating the overall losses can be reduced even further. Obviously, the crop conditions as well as land and climate needs to be favorable for such low loss level.

Pesticide application is an essential practice on many U.S. crop farms. Off-rate pesticide application errors may result from velocity differential across the spray boom while turning, pressure fluctuations across the spray boom, or changes in boom-to-canopy height due to undulating terrain. The sprayer path co-ordinates and the status (on or off) of each boom control section were recorded using the sprayer control console which provided map-based automatic boom section control. These data were collected for ten fields of varying shapes and sizes located in central Kentucky. In order to estimate potential errors resulting from sprayer turning movements, a method was developed to compare the differences in application areas between spray boom control sections. The area covered by the center boom control section was considered the ''target rate area'' and the difference in these areas and the areas covered by remaining control sections were compared to estimate application rate errors. The results of this analysis conducted with sprayer application files collected from ten fields, many containing impassable grassed waterways, indicated that a substantial portion of the fields (6.5-23.8%) could have received application in error by more than ±10% of the target rate. Off-rate application errors exceeding ±10% of the target rate for the study fields tended to increase as the average turning angles increased. The implication of this is that producers may be unintentionally applying at off-label rates in fields of varying shapes and sizes where turning movements are required.

No abstract