Poor South Africans spend 50 percent of their income on food, making them particularly vulnerable to rising food prices, Reserve Bank Governor Tito Mboweni said on Tuesday.

"South Africa is dealing with a problem of food affordability, rather than food availability," he told a symposium of the Cape Pomological Association in Stellenbosch.

"Internationally, concerns currently focus on the availability and prices of food, and in particular of basic staple commodities such as maize and rice."

Mboweni said food prices increased at a year-on-year rate of 15.9 percent in April.

"This has serious implications for poor people and the unemployed, as their spending on food as percentage of total spending is much larger than is the case with the middle and high income groups.

"Food accounts for more than 50 percent of the spending basket of the low income group, compared to some 17 percent of the spending of the highest income group, and some 20 percent of the overall CPI (Consumer Price Index) basket," Mboweni said in a speech posted on the Reserve Bank's website.

He reiterated that South Africa was not expected to return to its inflation targets of between three and six percent before end-2009.

"Food and petrol prices are the main contributors to inflation, but in recent months, more generalised price pressures have emerged as well," said Mboweni.

"According to our most recent forecast, inflation is expected to persist above the inflation target of three to six percent, and is not expected to return to within the range before the end of 2009.

"The road ahead is going to be bumpy".

In attempts to curb inflation, the Reserve Bank has increased interest rates by 450 basis points since June 2006 and is expected to announce another increase this month.

Sapa