THE development of new herbicides for grass weed control in cereals and rice, announced at a conference in Europe last month, is exciting news for Australian farmers working to manage herbicide resistance, according to University of Western Australia professor and Grains Research and Development Corporation director, Stephen Powles.

Stephen Powles

Professor Powles, who attended the IUPAC congress on crop protection at Ghent, Belgium, where the announcements were made, said it was extremely rare for new chemistries or modes of action to be developed.

Among the new chemistries, FMC, which is a major player in the crop protection discovery business, has come up with a new selective herbicide, tetraflupyrolimet, for the control of grass weeds in rice.

“The truly new herbicide from FMC is tetraflupyrolimet. In case you were wondering, it stops nucleic acid synthesis by inhibiting dihydro orotate dehydrogenase! It controls grass weeds in rice. It is not on the market yet, but it’s on the way,” he said.

Professor Powles said another promising development was that by Bayer Crop Science of a selective herbicide, aclonifen, to control grass weeds pre-emergent in cereals.

“It looks like it will have a retail name, Bandur. It is an older chemical. It’s a new mode of action. Very encouraging,” he said.

At the same time, Professor Powles said Japanese company, Mitsui Chemicals Agro, announced the development of cyclopyrimorate, a selective herbicide with a novel mode of action for the control of weeds in rice.

Both aclonifen and cyclopyrimorate are inhibitors of an enzyme called HST.