Destroying weeds and not the planted crops has always been a problem which for a long time demanded a large workforce and, more recently, the use of herbicides. Yet, today, there are robots capable of accomplishing this task if the weeds are between rows of crops or between regularly spaced plants. But what if the crops and weeds are mixed? Researchers at the Gembloux Agro-Bio Tech have perfected a recognition method based on the height of plants.
The Mechanics and construction division manager of the Gembloux Agro-Bio Tech, Professor Marie-France Destain, explains from the outset the research being carried out by her laboratory today: “The division has always been concerned with the mechanization of agriculture. Yet for the last few years, we have focused on sensors and automatic systems. Computer vision is obviously a very important factor in this context. However, it is a very particular form of computer vision as it is situated in an external environment; this is very different from the industrial environment where there is constant light, for example. In this case we are dealing with fluctuating light, where the ground is very variable, etc. The environmental conditions change constantly. We began by checking the quality of fruit and vegetables and a spin off (Visar) was created which offers real-time sorting machines for carrots or potatoes. We have also carried out checking of seeds. In the context of a new Master’s degree in the science and technology of the environment, our experimentation in computer vision has been redirected towards environmental matters and in this way we succeeded in the recognition of weeds. This is an important challenge because currently we use a lot of herbicides with all the known consequences thereof. Yet in organic farming, the regulations are very strict and today require the work to be done almost manually! A company contacted us to study the idea of a robot which could recognize and destroy weeds automatically.”
Every gardener knows that it is necessary to destroy weeds: they absorb light, water, nutrients and space to the detriment of plants that we want to cultivate. There is also the problem of the seeds they produce which are dispersed by the wind. As everyone knows, there are several ways of getting rid of them: chemical, non-chemical, integrated or most often, a combination of methods. The idea of trying to destroy weeds by the use of robots is not new. Some robots are already commercially available but they can only be used when the gap between the rows and the plants is known in advance (and when this gap is well-kept of course!).