Farmers should plant mustard in their fields to stop beetles eating their crops, scientists discover

Botanists studied the effect of planting different crops among the oil seed rape

Farmers have stopped planting oil seed rape since a pesticide ban - but now there are other options

Farmers should plant mustard among their crops in order to protect them from damaging insects, scientists have found.

Powerful pesticides which were often used for oil seed rape plants, called neonicotinoids, were banned by the EU in 2013. This caused farmers to desert the crop, because they could not protect it from the flea beetle, which feasts on the plant.

The agricultural industry will also have to find new ways to protect crops from pest bugs without using pesticides, as the government slowly phases them out for environmental reasons.

Botanists have been working to find out whether planting other species alongside vulnerable crops such as oil seed rape can keep pests away.

The National Institute of Agricultural Botany tried three different types of plant over five years, planted next to oil seed rape.

Some, such as buckwheat, are thought to repel the flea beetle, and others, like legumes, lock nitrogen into the soil and cause the oil seed rape plants to grow big and strong enough to withstand attacks.

However, the most successful crop planted alongside the oil seed rape was mustard, which the flea beetles find irresistible. They sat in their thousands on the mustard plants, munching away, and left the important crops alone.

Dr Aoife O' Driscoll from the institute told the BBC's Farming Today:  "In the trials we've done over the 5 years mustard has been the one where we have really seen a difference.

"The flea beetles really tend to go for the mustard rather than the oil seed rape, and you really see them sitting on the mustard and not going for the oil seed rape. Mustard can really tolerate a lot of damage from the flea beetles and it just keeps growing."

Planting other crops in this way is also good for the soil in which the oil seed rape grows; diverse plants lock different nutrients into the soil and keep it healthy, helping the crops.

Biodiversity is improved by planting other vegetables and grains around the main crop, as different pollinators prefer a diverse range of plants.