Study of tractor velocity variations in coffee cultivation.

The quality of weeding and fertilizing operations was determined in a coffee plantation. A mower and a fertilizer distributor were mounted on a tractor equipped with an automatic data acquisition system. A global position system (GPS) was used to determine the location of the machinery in the field and to calculate the forward velocity. Spatial velocity variations for both cultivating operations were small. The data acquisition frequency was adequate and permitted analysis of the work quality. The automatic data acquisition system was efficient, showing its applicability as an automation tool for mechanized field operations management.