Own variety mixtures of winter wheat – methods and experiences

The Innovation Center for Organic Farming, together with two organic farmers, has tested two methods for creating their own variety mixtures of winter wheat.

By Karen Munk Hansen

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Variety mixtures are generally more robust in terms of diseases and yield than single varieties, and if the varieties in a mixture have different growth habits, the mixture may also provide better weed competition than the same varieties grown as pure stands.

There are ready-made variety mixtures on the market, but if you have specific preferences for the composition, you can also mix them yourself. If you purchase a ready-made mixture from a supplier, the varieties have been evaluated for cultivation in combination, and the seed is delivered in a single batch. If you mix them yourself, you have greater flexibility, but you must carry out the variety assessment yourself, and there may be multiple deliveries to keep track of.eedom, but you have to do the variety evaluation yourself and there may be several deliveries to keep track of.

Three varieties in the mixture

In a demonstration trial with two organic farmers, mixtures of the varieties Pondus, Pacman and Fritop were sown in a 1:1:1 ratio. The varieties were selected on the following basis:

Pondus is marketed for both conventional and organic cultivation and has performed well in terms of yield over the past five years in the conventional National Field Trials. It has a “flat” growth habit, which may potentially provide good ground cover against weeds in autumn.

Pacman has delivered top yields in the variety trials of the National Field Trials® in recent years. As of September 2025, it has been moved to susceptibility group 3 for yellow rust.

Fritop has a modest yield potential in pure stand, but it is taller than the other two varieties, which provides good weed competition but also increases the risk of lodging. It has awns, making it easy to recognize already at heading.

At both locations, the variety mixture was sown using a 6-metre Väderstad Spirit seed drill. The plots are 30-36 metres wide.

The seed can be delivered directly to the field, and the varieties are placed in layers in the seed drill.

Mixing can also be prepared using a front loader on the barn floor. This method produces a uniform mixture.

Experimental design

Demonstration trials at two locations
Two treatments: Seed mixed on the barn floor and seed mixed by layering in the seed hopper
Plots: Four to six adjacent drill rows (tramlines) of each treatment, with two replicates at each location
Plant population and sowing depth as normally applied by the host farmers

Two mixing methods tested in practice

The mixtures were prepared in two different ways:

By mixing the varieties with a front loader on the barn floor
By placing the three varieties directly into the seed drill in layers and allowing the mixing to occur during sowing

The quality of the two methods was assessed in the crop in the field.

The first method is more labour-intensive and involves some transport when refilling the seed drill. The second method can be carried out directly in the field, but experience shows that the seed drill must operate for around one hundred metres before a cone effect develops in the seed hopper and the mixture of varieties becomes uniform.

Advantages and disadvantages of the methods

Both mixing methods work in practice with three varieties, apart from the slightly uneven start when using layered mixing in the seed hopper. If you wish to mix more varieties, floor mixing will likely provide the best result in the field.

There are advantages and disadvantages to both methods, and the two host farmers each prefer their own method.

Floor mixing

Mixing in seed drill

Additional work operation for mixing on the floor

Transport required when refilling

Greater risk of spillage

Possible to mix a larger number of varieties

Labour-efficient with less risk of spillage

Seed can be delivered directly to the field

The mixture is only uniform after approx. 100 metres of driving

Refilling should take place before the seed hopper is completely empty

The seed rate on the drill must be adjusted after a couple of runs, once the mixture has become uniform

The variety Fritop has awns and is taller than the other varieties in the mixture. Clear varietal differences make it easier to assess the quality of the mixing in the field.

The grain in the first drill pass when mixing directly in the seed hopper is slightly lighter in colour. The variety Fritop was placed at the bottom of the hopper, resulting in an overrepresentation of this variety until proper mixing is achieved throught air pressure.

The National Field Trials provide further knowledge

The variety mixtures performed very well in both demonstration trials. Overall, there was a low incidence of fungal diseases in the trials, and no differences could be observed between the mixing methods.

With the experimental design applied, no final conclusions can be drawn regarding the health or weed competitiveness of the variety mixtures. However, we expect to obtain a solid data basis from the National Field Trials in 2025 and 2026, where different variety mixtures and single varieties have been evaluated in terms of yield, weed competitiveness and disease susceptibility.

See results from National Field Trials 2025

Briefing note: Experiences with mixing winter wheat varieties for own variety mixtures (pdf 15 pages)