Environment: Dutch Elm Disease



Glenye Cain writes: George Sassoon, a lucky man to be in the lovely Wiltshire countryside these days, wrote: "Dutch elm disease - a fungus and/or insects - in fact came from Canada in a shipment of timber via Holland.  North American elms are apparently immune to it."  I wish that were the case! Alas, North American elms are also susceptible, as described at http://www.ext.nodak.edu/extpubs/plantsci/trees/pp324w.htm

From that site: "Dutch elm disease was first found in the United States in Ohio in 1930. It has now spread throughout North America and has destroyed over half the elm trees in the northern United Sates. The disease has been reported in all states except the desert Southwest. "Dutch Elm Disease (DED) was first found in North Dakota in 1969 in Mandan. It was discovered in eastern North Dakota in 1973. By 1987 it had become established throughout eastern and central North Dakota and reported from all counties except those in the extreme northwestern part of the state.

"Dutch elm disease is caused by the fungus Ophiostoma ulmi (syn. Ceratocystis ulmi) which is transmitted by two species of bark beetles or by root grafting. The American elm, Ulmus americana, is the most seriously affected of all elms. The Siberian elm, Ulmus pumila, (colloquially called 'Chinese elm' in North Dakota) is tolerant but not immune to the disease."

Glenye Cain, not quite as lucky as George but enjoying the California flora at the moment.







Ronald Hilton 2005

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last updated: April 16, 2005