Precision and Automation Technology for Weed Control

The world population is expected to reach 9 Billion by 2050.  This presents a challenge when considering the land and other resources globally available.  There are 6.6 Billion acres of arable land and it takes 1.2 acres to feed one person.  Currently, we can only feed 5.5 Billion people, which is dreadfully short now and in the future.  To meet the food demand, we need to either increase the amount of arable land or reduce the number of acres required to feed one person.  This raises the obvious question of how to accomplish this in such a short period of time.  The answer lies in getting more precise in managing our resources – land, water, light and inputs (fertilizer, herbicides, and insecticides). 

In the last few decades, agriculture has advanced rapidly in its adoption of new technology.  This trend should continue into the future if we are expected to feed the growing population.  In cropping systems, a combination of biology and engineering have recently merged to address management tools designed to respond to the dynamics of nature of land, air and water.  Sensor technology has been one of the most rapidly developing areas of technology with widespread in agriculture. 

Crop production is most often by the acre and in most cases inputs are applied and averaged by an entire field using equipment that spans multiple crop rows.  Weeds in productions systems often occur in patches of various sizes or as individuals growing among crop plants, yet they are managed in large scale and uniform.  A combination of chemical, mechanical and cultural methods is used as a weed control strategy at different time of the season or over several seasons.  Rarely, single weed plants are targeted.  Weeds are not managed at the individual plant scale. 

With advances in precision treatment, weeds can be controlled with ultra-low doses of herbicides, applied directly to the target at a very early life stage.  This practice significantly improves efficiency and crop yields.  For example, some micro-dose systems have the potential to control 1000 weed seedlings per square foot with a 0.06 ounce per acre of glyphosate. 

There is no doubt, precisely placed herbicides can be very effective in controlling weeds, but the commercial availability of precision application equipment is limited by its robustness in a wide variety of field conditions, including fluctuating weather and changing plant canopy and architecture.  On the other hand, targeted recognition and application technology for precision weed control must be easily incorporated into current systems and implements. 

The use of sensors and computers (guidance technology) to quickly access plants and their location within a field has led to the development of various systems.  However, little is known about the precise rates of herbicides needed to control very small weed seedlings.  By using technologically equipped machinery that can target individual weeds in real time, there is no limit to the number of control tools for use in the field at any one time. 

Both biological research and technological developments in weed control have the potential to radically change the current approach to weed control and significantly reduce environmental impacts as well as the high cost of inputs and labor. 

The broadcast application of herbicides is affecting our ecosystems (e.g. run-off, drift, and ground water contamination) and causing entire cropping systems to fail (e.g. herbicide resistant weeds), signaling the need for a more precise weed management approach that includes the right dose at the right place and time.  Precision weed management is better for the environment and better for the producers as it leads to a reduction of herbicides and other costly inputs without decreasing weed control efficacy.   

For more information on Weed Control Technology, please contact your local Colorado State University Extension offices or visit us at: http://www.ext.colostate.edu/.

By Wilma Trujillo
CSU/Prowers County