Integrating Variable Rate Technologies for Soil-applied Herbicides in Arizona Vegetable Production

Since the mid 1990’s, advances in global positioning systems (GPS), microprocessors, actuators, controllers, plant/soil sensors and geographical information systems (GIS) have spawned the development of new, site-specific, variablerate techniques for chemical applications. At the same time, agricultural production has embraced other new technologies that increase the productivity of mechanized operations such as tractor auto-guidance systems. The combination of automatic tractor steering and variable rate technology is well suited for site-specific application of pre-emergence herbicides. With tractor guidance control and variable rate controllers, growers can increase the efficiency of chemical application by eliminating swath overlap, while increasing the efficacy of herbicide action by applying optimum rates based on soil texture.