Science: Twilight of the Elms

The stately U.S. elm, which inspires the weekend artist and dandles the infant oriole, is in worse danger than ever. Last week, the U.S. Department of Agriculture warned that the Dutch elm disease, a familiar menace in the Northeast, had spread during the war into new territory: Delaware, Kentucky, Vermont, Virginia. Sweeping out of the Middle West was an even more deadly disease, phloem necrosis, which kills thousands of elms every year.

No one knows how phloem necrosis spreads. Dutch elm disease is better understood; it is a fungus carried from elm to elm by small bark beetles. They slip through the meshes of the strictest quarantine. Spraying will kill them, and the Department is experimenting with DDT and its rival, benzene hexachloride (“Gammexane” in Britain; TIME, June 24). But it is not too hopeful. There are too many elms to spray.

The Department does not think that all U.S. elms will die of disease, as did nearly all chestnut trees a generation ago. It does believe that the Gothic elm avenues in many towns will disappear, and it advises city landscapers that elms arc poor investment.

Best hope for the future: resistant varieties. Siberian elms are not killed by Dutch elm disease—which probably indicates that the fungus came originally from Asia. The Buisman elm of The Netherlands is resistant also. The Department is already experimenting with fungus-defying hybrids. Perhaps, in a century, there will be an elm renaissance.