Tunisia plants seeds of hope against climate change
Traditional seeds come from a genetic heritage best suited to the environment, said Maher Medini, from Tunisia's National Gene Bank, which promotes the development of sustainable agriculture in the country.
"They are reservoirs of genes hundreds, if not thousands of years old," Medini said, adding that the seeds are more resistant to the ever-growing dangerous impacts of global warming.
Climate change is causing challenging variations in rainfall, temperature and humidity, creating disease in the crops, he said.
"The foundation of adaptation is diversity," Medini said.
Wheat varieties developed in the 1980s are being blighted by disease in Tunisia, but farmers say that traditional varieties appear to be more resistant.
In the past, using indigenous seeds, Tunisian farmers set aside a small part of the harvest to sow in the next season.
But the development of hybrid or genetically modified seeds resulted in better harvests, and native varieties largely fell out of use.
One problem is that seeds from the new varieties cannot be replanted, and farmers have to buy in more seed every year.
A Tunisian farmer harvests wheat in the Jedaida region, some 30 kilometres (18 miles) northwest of the capital Tunis.
Wheat varieties developed in the 1980s are being blighted by disease in Tunisia, but farmers say that traditional varieties appear to be more resistant.
The UN's Food and Agriculture Organization estimates that over the past century, around three quarters of the diversity in world crops has disappeared.