Cultivar mixtures can provide several advantages, such as reducing the spread of fungal diseases, lower infestations on plants and obtain more stable yields. Mixing varieties in the field can also extend the disease-resistance of the plants.
The effects of cultivar mixtures have mainly been studied for grain crops and fungal diseases spread by wind. When for example cultivars with different susceptibility to powdery mildew are mixed in fields, both physical and phytochemical barriers to harmful fungal spread in the field are created.
Cultivar mixtures, insect pests and natural enemies
A mixture of varieties may also have an effect on pests and natural enemies. This has been demonstrated by researcher at SLU and Stockholm University in the cooperation project PlantComMistra.
With the right cultivar mixtures of spring barley the communication between the varieties increased which made the crop stands less attractive to aphids. Also natural enemies benefited from the mixtures, for example, some combinations of spring barley were more attractive to ladybugs and lured them into the crops even before the plants became infested with aphids. This of course increases the prospects for effective biological control.