Mzuzu — Every morning, Bernadette Kilembe, from the northern Malawian town of Karonga, is confronted with two related problems: She has to keep her restaurant running, and she has to feed herself and her three children.

Exacerbating both of these problems is the cost of maize - Malawi's staple food - which has become unaffordable.

Between June and October 2012, a 20-litre bucket of maize cost her between 500 and 750 kwacha (about US$1.50 to $2). Now it costs 3,000 kwacha ($8) a bucket.

"That is only enough to produce two meals for me and my children," said Kilembe.

In a good year, Kilembe grows enough maize in her garden to supply her restaurant and feed her family, but dry spells during the 2011-2012 growing season wilted her crop. Unreliable rainfall is nothing new in Malawi, but in the past, Kilembe could purchase affordable maize from local vendors. This year things are different.

During and after the 2012 harvest, cross-border traders offered farmers in the area much better prices than those offered by local traders.

"Most of the farmers here thought if they sold their maize and kept the money, they would be able to buy from the market once the maize they stored for their own consumption was depleted," said Masuzgo Zowani, a community worker and subsistence farmer from Chirambo, in western Rumphi District.

"Unfortunately, they did not know that they were creating a gap in the supply of maize both in their area and the country generally because those who offered the better prices took the maize out of the country. Now they can hardly afford the maize that is found on the market."

Exports banned

A ban on the export of maize from Malawi was implemented in December 2011, when it became apparent dry weather threatened to cause a maize shortage.

But the ban has not prevented traders from smuggling maize across the border into neighbouring Tanzania and Mozambique, where the weakening of the kwacha against the dollar has made Malawi's maize attractive to buyers.

"When trucks bring bags of maize here [from surrounding areas], it is not meant for our market," said Kilembe. "We don't know where it goes, as the maize often comes late in the evening when we are about to sleep and it is not [there] by daybreak."