14 March 1996

Customer resistance threat to GM rape

BY Allan Wright

GENETICALLY enhanced varieties of oilseed rape await only EU approval before being released for commercial use.

But growers were warned last week that benefits had to be weighed against disadvantages, not least consumer resistance.

"Possible consumer resistance to rapeseed products must be seen as a considerable threat," Dr Kerr Walker, oilseeds specialist with the Scottish Agricultural College told delegates to the Scottish oilseeds conference in Kinross organised by Crops, BASF and Semundo.

"The first commercially available genetically enhanced material will be herbicide tolerant varieties. But it seems that herbicide tolerance is seen by the public as being of less benefit to society than varieties with pest or disease resistance," said Dr Walker.

There were also negative aspects at farm level. Volunteers would be resistant to the total herbicide and there would be reduced choice of desiccant.

"There is also the possibility of the herbicide resistance gene being passed to brassica weed species, and the possibility of gene stacking where cross-pollination of varieties with tolerance to differing herbicides results in hybrids with multiple resistance," said Dr Walker.

He said the first commercially available herbicide tolerant varieties would be resistant to glufosinate-ammonium (Challenge), followed by those with glyphosate (Roundup) tolerance.

"These products are well known and understood by growers. They give an excellent degree of weed control and are effective against broad-leaved weeds and grass weeds – even perennials. The flexibility of application timing is also attractive and these chemicals may be less environmentally damaging than those applied to conventional rape varieties," said Dr Walker.