Genetic engineering of trees has been slow to grow. One reason being money, according to Ron Sederoff, director of the Forest Biotechnology group at North Carolina State University and head of a dozen research consortium supported by a a dozen firms interested in genetically engineered trees. But the trend is changing because the international demand for wood has grown 36% in the past 25 years and is now $400 billion business, according to a report on the world's forests published by the United Nations Food and Agriculture Organisation last year. This puts pressure on commercial plantations: and there are fewer virgin forests left to cut. Hence a new enthusiasm for manipulating the genetics of trees.