Proceedings of the First Park Naturalists’ Training Conference, November 1 to 30, 1929
CONTROL OF THE WHITE PINE BLISTER-RUST
By Stephen N. Wyckoff
(Note: Mr. Wyckoff spoke extemporaneously. The following paragraphs present a brief of his remarks.)
The white pine blister-rust was introduced in the United States from Europe many years ago on nursery stock imported from Germany. The disease escaped and spread rapidly throughout the East, where it has practically exterminated the white pine. At present it is such a great menace that it is now practically impossible to raise plantations of white pine, even though economic conditions are such that these plantations would otherwise be profitable.
The white pine blister-rust has spread rapidly across the continent and is now found in northern Idaho. It has reached the Pacific Coast and has turned southward toward the immensely valuable stands of 5-needle pines in California. At the present time it is known to be at Port Orford, Oregon, which is only fifty miles north of the California line and in all probability the disease is present in California, although we do not know it. I feel quite certain that the disease is already in Mount Rainier National Park, and that Crater and Glacier National Parks will soon be infected, if indeed, they have not already been.
An area infected with white pine blister-rust is a most unsightly place. Unfortunately the disease gains headway without our knowledge and practically never can its presence be detected on trees until three or four years after the initial infection has taken place.
The disease lives on two host plants. The first stage it must live on the Ribes — currents and gooseberries. The spores are carried from these plants to the 5-needle pines. These spores are seldom carried more than 1500 to 2000 feet; therefore, the pines can be protected by eradicating all the Ribes plants from the surrounding area. This, however, is extremely costly.
In the second stage of the disease it lives only on the white pines — pines of the 5-needle group, including western white pine, sugar pine, and their relatives. In this stage the tiny spores travel for vast distances, sometimes being carried as far as 150 miles before infecting gooseberries or currents and thus starting a new cycle. The tiny spores from the pines spread especially well in wet weather.
When it is known that the white pine blister rust is approaching a park or a forest, the best plan is to prevent infection by eradication of Ribes. If control is delayed until after some of the pines are infected then eradication of Ribes will prevent infection of other pines, but will not prevent the disease from passing on to infect the currents and gooseberries in other areas beyond.
Millions of dollars have been spent by the federal government in attempting to eradicate this terrible disease. Time after time our battle front has shifted; and now you might say we have our backs to the wall and are making a last stand to protect the enormously valuable white pine forests of the Pacific Coast.
In the discussion following Mr. Wyckoff’s address, details wore given relative to methods of control of the white pine blister-rust. Mr. Wyckoff distributed pamphlets telling about the disease and suggested that the park naturalists be alert to detect infection in their individual parks.
Mr. Wyckoff stressed the need for cooperation between the park naturalists and the field officers and control crews of the Blister-Rust Control when once the disease has become established.