Science is coming to the rescue of the world's second-largest brewer as drought ravages its South African barley-producing heartland.

John Rogers, director of agricultural procurement for Africa at SAB and AB InBev, said new technologies were being introduced to reduce water use.

"We look at drought resistance within agricultural production systems" Rogers said at a Growers Appreciation Day in the Overberg region.

The Western Cape, which produces more than 80% of South Africa's barley, is in the grip of its worst drought in 100 years.

"First it starts with genetics and the development of varieties that are more efficient with the water that's available to them. We are developing cultivars that can handle higher temperatures and require less water."

Rogers said they had been able to reduce water use through irrigation by more than 30% in parts of the country.

Since being bought by AB InBev, SAB has announced investments of more than R3-billion in agriculture.

The company also plans to incorporate emerging farmers into its hops, barley and maize supply chains.