By Marianne Landzettel South Asia editor, BBC News

	Rice is a staple food for almost half of the world's population

She was speaking at a conference commemorating the fiftieth anniversary of the International Rice Research Institute, IRRI.

Rice is a staple food for almost half of the world's population and farmers in rice producing countries face two great challenges: to meet the growing demand while climate conditions are changing.

In Bangladesh rising sea levels have increased the salinity of the soil enormously.

Increased population

Scientists from the Bangladesh rice research institute say they have developed a rice variety that can cope with these new conditions, but it will take about three years until the seeds are available to farmers.

With the help of the IRRI farmers in Bangladesh have been able to increase rice production to keep up with a population that has tripled in the last 50 years.

But Sheik Hasina told scientists that they now needed to come up with high yield varieties that also withstand floods, salt water or are drought resistant.

We have to produce rice that will adjust to the changing climate, she said.

The International Rice Research Institute which works with national organisations in all rice producing countries is using its large genetic data base, containing 2.7 million rice samples to create new varieties.

But they also help individual farmers with practical advice: farmers in the Philippines will soon be able to get information from the IRRI via text message.