BASF, the German chemical group, said that it had developed a new generation of genetically altered crops, by precisely manipulating the plant’s own DNA without inserting foreign genes.

The technology, known as “directed mutagenesis”, produces new traits such as herbicide resistance, which are very similar to those achieved through conventional genetic modification of plants. But because no genes are added, it is likely to avoid the political and regulatory objections that have delayed the introduction of GM crops, particularly in Europe.