Wageningen UR’s test fields in Lelystad can be used to test various pesticides simultaneously, with almost surgical precision. This is thanks to computer-controlled sprayers that are linked to a Real Time Kinematic GPS. “This lets us dose up to ten agents at the same time on different sections of a test field, with an accuracy of two centimetres,” says Pierre Bakker, director of the testing facility in Lelystad.
Test field as a checkerboard
In a field trial which compares several pesticides, the field is usually divided into a kind of checkerboard. “Instead of an employee with a knapsack walking up and down to spray each new agent, such a test field can now be treated all at once with all the agents being tested,” Bakker explains. “The tractor driver programs the sprayer in advance via a computer and can monitor from the cabin exactly which agent is sprayed where in the field and at what moment.”
Advantages automated spray system
“The use of this automated spray system with GPS has many advantages,” research manager Piet Spoorenberg adds. “Since the agents are dosed in a single run, there is no loss of time between the treatments of the various sections. All the agents are therefore dispensed under exactly the same conditions. There are no longer any differences in wind, moisture or other conditions to take into consideration. Moreover, we also avoid exposure of employees who previously had to dose each plot with a knapsack sprayer.”
Less space required in crop protection trials
One of the companies which already has experience with the automatic spray system is Bayer. “We also have our own sprayers so can treat test fields quickly with successive agents,” Roel Wanningen of Bayer says. “However, when switching from one treatment to the other, we must always maintain a greater margin between the sections of the field where the different agents are used. Computer-controlled injection requires much less space. Moreover, in the system used in Lelystad the likelihood of human error during spraying is much smaller.”
According to Spoorenberg, the use of the GPS-controlled sprayer is typical of a period in which technology regularly offers new possibilities to researchers. “We are now seeing a similar technological push in the form of so-called quadrocopters. These are relatively inexpensive remote-controlled helicopters fitted with a camera underneath, which we also deploy to inspect test fields from the air.”
After the first practical experiences in 2013 with a broad range of crops and test conditions, the fully automated GPS sprayer will become the new standard for spray tests on and around the experimental farm in Lelystad this year.