28 March 1997

Virus tolerant types popular

BIOTECHNOLOGY is delivering potatoes with immunity to pest, virus and disease, delegates at the World Potato Congress in Durban, South Africa, heard earlier this month.

Growers in North America are already using three varieties of potato resistant to colorado beetle.

NatureMark, a subsidary of Monsanto, is marketing Russet Burbank, Superior and Atlantic with resistance to colorado beetle all under the trade name NewLeaf.

Genetic modification added a protein from the naturally occurring fungus, Bacillus thuringensis which prevents the beetles feeding.

Next year NewLeaf Plus varieties will have resistance to potato leafroll virus as well as Colorado beetle. The year after NewLeaf-Y varieties will contain resistance to potato virus Y plus Colorado beetle. And in 2001 varieties resistant to blight are planned.


This year over 4000ha (10,000 acres) of the NewLeaf colorado beetle-resistant varieties are being grown in North America. Saving on organosphorous insecticide sprays is a significant benefit.

"NewLeaf potatoes not only protect the environment but eliminate the hassle of insecticide application; many growers in North America use aerial application," pointed out NatureMarks Gary Hawkins.

The cost of NewLeaf seed? "It varies according to region. The price is adjusted to regional pest pressures – but never to discount the net benefit."

Next year Mr Hawkins expects the area of NewLeaf varieties to increase five-fold.

Plans for expansion into Europe depend on the current biotechnology debate. In North America the new varieties are seen as a positive environmental benefit – in supermarket trials NewLeaf varieties were favoured over conventionally and organically produced potatoes – whatever the price.n