Johannesburg - South African wheat futures dropped for a fifth day to the lowest in more than three weeks as the rand strengthened against the dollar, making imported grain cheaper.

Wheat for delivery in March, the most active contract, decreased 0.6 percent to 3,524 rand ($396) a metric ton, the lowest since January 11, by the close on the South African Futures Exchange in Johannesburg.

The five-day retreat is the longest losing streak for a most active contract since April 17.

The rand has appreciated 0.5 percent against the dollar this month, the biggest increase among major currencies, according to data compiled by Bloomberg.

“The rand strengthening has caused downward pressure on wheat prices,” Andrew Fletcher, an independent trader, said by phone from Kroonstad in the Free State province.

South Africa is sub-Saharan Africa’s biggest importer of wheat after Nigeria and Sudan and its largest producer after Ethiopia, according to US Department of Agriculture data.

Yellow corn for July delivery declined 0.3 percent to 1,923 rand a ton, while the white variety, also for delivery in July, fell 0.8 percent to 1,882 rand a ton. - Bloomberg