Weed is not only a major problem for farmers in developing countries but farmers in rich countries are also facing increasing weed problems. This is the view of Bert Lotz of Plant Research International. Problem is that an effective and broadly applicable mechanical control method will not be available for some time.
Photograph: Increasing weed pressure in forage maize.
FAO, the UN world food organisation, recently reported that weed is an underestimated problem. According to a study quoted by FAO weeds cause more damage to food supply than pathogens or insects. Lotz endorses the increasing significance of weed.
Written off
Lotz knows from experience that in Africa weed sometimes causes a third of the acreage to be written off half way the growing season. Weed is an increasing problem in conventional agriculture in the Western world as well." Fields are increasingly infested by weed species that are difficult to control with the currently available products.
According to Lotz, the limits to growth have been reached sixty years after the large-scale introduction of herbicides. “Weed shows an increasing resistance against products precisely at the time that the agrochemicals industry is finding fewer active substances for addition to the product range.”
Solution
The solution is to be found in an integrated approach. “In addition to more precision, variation in control methods is required. Better insight into the total system is needed for both.”
Lotz mentions Robot Ruud as an example; this robot attacks round-leaved dock with a hoe. Robot Ruud is currently being developed for organic farming. Problem is that such fully automatic applications are expected to take 10 to 20 years before reaching the conventional market. Growers should, however, not get the impression that they can then lean back and let the robots do all the work. Growers will in the future closely be involved in weed control by robots, e.g., by taking measures when things go wrong. These developments will strongly improve the usability of robots.