The March contract for white maize added almost 2.6 percent to a new record of 4,781 rand ($307) a tonne while the same contract for the yellow variety climbed 1.8 percent to 3,677 rand a tonne.

Prices for white maize, the staple crop that provides much of the caloric intake for South Africa's lower-income households, more than doubled in 2015 while those for yellow maize, used for animal feed, rose around 70 percent last year.

"We are past optimal planting times in much of the Free State province and North West. The guys cannot plant because it is too dry," said one local maize trader, referring to the key growing areas in the western part of the maize belt. Even the crop that has been planted is suffering in this heat."

After the market closed, Agriculture Minister Senzeni Zokwana said South Africa, the continent's top maize producer, might have to import the grain if the drought persists.

"If there is no rain, we may be compelled to import maize around May or June," Zokwana told journalists.

The searing drought has been exacerbated by an El Nino weather system, a warming of ocean surface temperatures in the eastern and central Pacific that occurs every few years with global consequences. It follows a bad harvest last season when dry conditions shrivelled the maize crop by a third to 9.94 million tonnes, the lowest since 2007.

This is worrying for policymakers. South Africa's central bank, which is in a tightening cycle, has frequently expressed concern about the impact of the drought and food price pressures on inflation in Africa's most advanced economy.

(USD $1 = 15.5495 rand)

Source: Reporting by Ed Stoddard; Editing by James Macharia, Thomson Reuters Foundation