Therapy for Dutch Elm Disease    (View PDF)

Gerald N. Lanier

Abstract: An aggregate of 82 American elms in Syracuse New York and Washington D.C. naturally infected with Dutch elm disease were given therapy by pruning infected limbs, injection of benzimizol fungicides, or combinations of these treatments. Pruning alone was applied only when there was a distance of 3 m or more from the last visible streak to the distal cut. Pruning without injection was successful in each of 10 current year infections, but in none of 3 residual infections. Fungicide injection without pruning succeeded in 76% of current year and 33% of residual infections. Fungicide injection plus pruning was successful therapy for 100% of the current year and 71% of the residual infections. Each of five "incurable" trees showed no further symptoms after fungicide was injected directly into infected wood in a large limb or the bole as well as into the root collars. Relatively massive injection of fungicide in trees with root graft-transmitted DED did not succeed.

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https://doi.org/10.48044/jauf.1988.055