South Africa corn futures have reached their highest level in more than three weeks as the continued lack of rain raises concern about the harvest.

White corn for delivery in July, the most active contract, rose 1.1 percent to 2,057 rand (US$232) per metric ton, the highest since January 29, by the close on February 19 on the South African Futures Exchange in Johannesburg. The yellow variety for delivery in the same month gained 1 percent to 2,055 rand per metric ton.

There is no rain predicted until February 25 for Bothaville in the Free State, where 40 percent of the nation’s corn is produced, according to the South African Weather Service’s website.  “The lack of rain situation continues to pose a threat,” said Andrew Fletcher, an independent trader. “The market is now looking at production factors and that is taking the price up.”

A median estimate of six analysts surveyed by Bloomberg News showed that farmers may increase corn output by 5.9 percent to 12.5 million metric tons this season from 2012 numbers.