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Positive results from EU project on weed control in northern Germany and Poland

The EU project DSSHerbicide has had an outcome of results and experience on reducing herbicide use that can be directly transferred to farming practice in northern Germany and Poland. The next step is for more advisers and farmers to take the ideas on board.

[Translate to English:] Danske erfaringer og viden vedrørende bekæmpelse af ukrudt i vinterhvede har i et EU-projekt været udvekslet med Polen og Tyskland. Foto: Janne Hansen

Three years of sharing ideas, information and experience between scientists, advisers and farmers in Denmark, Germany and Poland have produced tangible results that each country can further develop in order to achieve a more efficient and sparing use of herbicides in winter wheat. This is the conclusion of the final meeting of the EU project DSSHerbicide that Aarhus University has been heading.


The project has built on Danish knowledge and experience on the use of the decision-making tool Crop Protection Online. The system helps crop advisers and farmers to decide on the most suitable weed treatment for specific situations. It can be optimised based on either treatment index or cost and takes into account the species, density and growth stage of both weeds and crops and seasonal and climatic conditions.


Crop Protection Online is well known among Danish advisers and farmers. The ambition of the DSSHerbicide project was to promote awareness and use of the system in the northern parts of Germany and Poland. A large part of the project has focused on adapting the system to the local conditions in the two countries based on practical experience and field trials. Local weed species and available herbicides and their cost are entered into the local versions of Crop Protection Online.


Challenges remain

The results from the two trial seasons in Germany showed that the treatment index could be reduced by anything from 30-44 percent compared to the standard solutions for the region and by 16-34 percent compared to the solutions proposed by local advisers. The yield was fully equivalent to the reference treatments and the average weed cover at harvest was below 10 percent. This has encouraged the German project partners to continue work with the system.


The Polish results were more variable but were on average 44 percent below the standard solutions. The limited range of herbicides in the decision support system gave large variations in the treatment index. The Polish scientists and advisers also stated that they would prefer to use the maximum dose to be on the safe side. Lower dosages were previously banned in Poland and there is therefore no experience with this practice.


There are still some hurdles to be overcome before Crop Protection Online can win the hearts and minds of the German and Polish advisers and farmers. The German, and particularly the Polish version of the program, needs to include a wider range of herbicides ? especially narrow-spectrum herbicides and herbicides against certain grasses.


The challenge ? which has also been a challenge in Denmark ? is to train advisers and farmers to identify individual weeds at a very early stage. This can be time-consuming, particularly if you have a lot of land, since it involves getting out to all the fields at the right time of the year.


Another challenge is to break with the conventional thinking that a wheat field must be free of weeds for the control to be satisfactory and to assume that the use of herbicides can be reduced without substantially reducing crop yields.


Farmers and advisers should consider the wider economic picture and look at what is most cost-effective when everything is taken into account, including the cost of buying and applying herbicides and offsetting with the proceeds of the harvest. The environment and the development of resistance in weeds must also be considered. Decision support systems can provide alternative solutions to the default choice when resistance-inducing treatment patterns need to be broken.


The original Danish Crop Protection Online has been developed in close cooperation between the Knowledge Centre for Agriculture and scientists from Aarhus University. The purpose of the decision support system is to protect the environment from unnecessary use of herbicides without reducing crop yields.


Link to Crop Protection Online. The tool is available in both an English and a German version. A Polish version is under way.


Additional Information: Scientific officer Mette Sønderskov, Department of Agroecology, e-mail: mette.sonderskov@agrsci.dk, telephone: +45 8715 8231