Danish seed production at the forefront

Danish farmers are eminent at producing seeds but in order to keep ahead of the competition they must be even better. Researchers from Aarhus University are partners in a project that will contribute to reducing the use of pesticides and increasing the yield in grass and spinach seed crops.

2017.08.16 | Janne Hansen

Researchers from Aarhus University are collaborating with the industry to maintain Denmark's leading position in seed production. Photo: Colourbox

Seeds do not take up much space individually but seen as a whole the production and export of grass and spinach seeds is important for Denmark. Danish farmers account for approximately half of EU’s total production of grass and clover seeds and 75 percent of the world’s spinach seed production. 

Seed production is something that Danish farmers are really good at but the production can improve even more. Higher yields and reduced pesticide use are at the top of the wish list. At the same time customers place high demands. Top quality grass seed must produce grass plants that isare fine, slow-growing, very dark and absolutely weed-free. With regard to spinach seeds, only three weed seeds are permitted in a 250 g sample that typically contains 20,000-25,000 spinach seeds. 

Researchers from the Department of Agroecology at Aarhus University are partners in a new research project, Vinderfrø2025, which aims to develop sustainable solutions for reducing the need for herbicides while producing higher, top quality seed yields. 

Even more and better grass seed

The agricultural package legislation passed in 2017 enables farmers to apply more nitrogen to their seed grass crop. This can increase yields but will probably also increase the need for growth regulation so that the seed grass does not lodge too early. 

- The past ten years have seen significant increases in yield in the two major seed grass crops perennial ryegrass and red fescue, but the potential has not yet been fully reached, says the leader of Aarhus University’s activities in the project, Senior Researcher Birte Boelt from the Department of Agroecology. 

One of the goals of the project is therefore to achieve a better and more stable effect of plant growth regulators via differentiated and targeted nitrogen application and determination of the crop’s precise requirements based on optimised monitoring of the crop. The goal is to find exactly the right combination of developmental stage, climate conditions, nitrogen application, and application time and dosage of the plant growth regulators using sensor technology, among other things. 

Another goal of the project is to reduce the use of herbicides in seed grass crops. This will be achieved by developing row cropping systems in which are used a combination of band spraying and inter-row mechanical weeding with treatments with selective herbicides in the rows. 

- In this way, we expect that we can reduce the herbicide treatment frequency by 50-70 percent, says Birte Boelt.   

Kentucky bluegrass with so-called 00-quality is used for lawns and sod, among other things. The big challenge here is that no weed seeds or other kinds of seeds are permitted in the product. 

- We will include measures throughout the crop rotation. Our hypothesis is that it is possible to produce 00-quality if the whole cultivation concept is adapted right from the choice of crop mix in the crop rotation to a strategy for chemical control, says Birte Boelt. 

Super spinach seeds    

Even though Denmark supplies approximately 75 percent of the world’s spinach seeds, we must not become complacent. Weeds and fungal diseases are the greatest challenges. The researchers will be testing various possibilities for establishing spinach and for preventing weeds and diseases. 

With regard to fungal diseases, the researchers will screen various cover crops for their preventive effect on wilt disease in spinach and investigate biological measures. 

To prevent weeds the researchers will investigate the possibilities for combining strip tillage and band spraying in the spinach rows with mechanical weeding or band spraying between the rows. 

Maintaining the lead

The project will work with a range of very current topics. The seed industry is experiencing growing problems with weeds, diseases and insects in grass seed crops while the risk of developing pesticide resistance is also growing. 

- It is high time to develop and demonstrate more robust and flexible cropping systems in which the crops are more resistant to pests. The project will find solutions that can be applied immediately to increase competitiveness for seed growers and companies so that Denmark’s presently strong position on the global market for grass and vegetable seeds can be maintained and expanded, says Birte Boelt. 

The four-year project Vinderfrø2025 has been granted 15 million DKK from the Green Development and Demonstration Programme (GUDP) and is a collaboration between the Danish Seed Council, which is the leader of the project, Seges, and Aarhus University. The project stands on the shoulders of the project 3030 i 2020 – mere græsfrø med relativt mindre input  (3030 in 2020 – more grass seed with relatively little input) and other research programmes. For example, the first trials with row cropping systems were carried out in 2000-2005 but weed control strategies were not included in the studies. 


For more information please contact: Senior Researcher Birte Boelt, Department of Agroecology, email: birte.boelt@agro.au.dk, telephone: +45 8715 8276, mobile: +45 2228 3328


Read more about seed research at the Department of Agroecology here.


Sustainable Pest Management is one of the research areas in which the Department of Agroecology is particularly strong and from which results are delivered in line with national and global societal challenges and goals.

Agro, DCA, Crops