6 October 1995

Now resistance barrier broken by Dutch maize

By Jessica Buss

HERBICIDE-RESISTANT forage maize could be available in the UK within three years, thanks to gene transfer technology.

Dutch maize breeder Van der Have has developed new varieties that are undamaged by weed control with a contact herbicide.

The breakthrough has been made possible by transferring a gene from soil bacteria to maize plants. It is this gene that breaks down the herbicide Basta when it comes into contact with the maize.

"Basta kills most weeds, including nightshade, and has the advantage of breaking down quickly in the soil," says Van der Have plant breeder Franz de Wolff.

As such it is seen as more environmentally acceptable than atrazine, one of the products used for weed control in maize crops. Mr de Wolff points out that atrazine is a residual herbicide that does not break down easily and has been found in water courses, and although it is thought harmless some concern about water contamination exists, he claims.

He says there are no problems establishing grass, or other crops, after harvesting the genetically modified maize when Basta has been applied.

It can also be used post-emergence, he says, so producers wishing to use mechanical weeding have more time to decide whether herbicides are needed.

Maize varieties containing the new gene will soon be tested so that they can be included in official maize variety lists, claims Cees Noome, head of Van der Have research.

He expects the approval process to take two to three years. Mr Wolff admits the genetically modified maize seed will be more expensive than that of existing varieties. "The market will decide the price," he says.

Resistance is most likely to be introduced in Van der Haves varieties Hudson, Facet and one new variety. These varieties will be renamed to avoid confusion.

&#8226 Basta (glufosinate-ammonium) is named Challenge or Harvest in the UK and should be licensed for use in resistant maize crops by 1997, says Les Sykes of chemical suppliers AgrEvo.

Van der Haves Cees Noome:"Maize varieties containing the new gene will be tested soon."