The first natural herbicide to be produced from a by-product of seed processing could soon become a commercial reality, according to Idaho University’s Don Thill, speaking at this year’s British Crop Production Council conference in Glasgow.

Mustard meal as a bioherbicide was undergoing Environmental Protection Agency regulatory testing and it was hoped that its US approval for use against a range of weeds would be gained within the next 18 months, he said.

“Glucosinolates in the seed meal have biocide/ bioherbicide properties and trials have shown that meal applied at 3t/ha pre-emergence can be very effective.”

As well as having bioherbicidal properties, the meal produced from crushing mustard seeds also contained 5-6% nitrogen, he added.

“The meal breaks down easily so much of this is available pretty quickly. You get around 60kg N per 1,000kg meal.”

Professor Thill said broadening the use of the entire mustard crop would be crucial if it was to take the place of the usual leguminous break crops in traditional wheat-canola (oilseed rape) rotations.

“The seed meal has to be a major element in this to make it profitable.”