Research into crop disease control without chemicals

A TEAM of German scientists at the Fraunhofer Institute for Electron Beam and Plasma Technology in Dresden say they have developed an organic method of protecting plants from disease by using electrons to kill fungal spores and viruses.

“Instead of using chemical products, we make use of accelerated electrons,” said team leader Olaf Roder. He said the electrons destroy the chemical bonds that hold together the molecules in fungal spores and other pathogens, without generating heat.

Meanwhile, scientists at Lancaster University have discovered a potential new way of making crops more resilient to pests.

The scientists found plants grown from seed treated with jasmonic acid (JA), one of a plant’s natural defences against being eaten, are more pest-resilient without any loss of growth. When a pest takes a bite of a plant leaf, JA is one of the chemical signals that warn other leaves to mobilise their pest defences, making them difficult to digest.

It has long been understood that by spraying crops with JA, plants stand a better chance of repelling pests like mites, caterpillars and aphids – however sprayed plants grow less well.

In early trials, the best results were on tomato plants, where attacks by red spider mites were reduced by 80 per cent, aphid attack was reduced by 60 per cent and caterpillar damage was down by a third. Caterpillar damage to wheat was reduced by 65 per cent and on maize, by 38 per cent.

Results from large-scale field trials are due at the end of this year. In the meantime, with new funding from Defra, the team at Lancaster is developing applications for the technology, including investigating its value in disease control.