dh321 at excite.com
Thu Feb 3 21:03:50 EST 2005
The toxic compound in Ailanthus is ailanthone, which also can be
extracted from root bark and stem bark. Are there any specimens you
could sacrifice? Ailanthus is usually considered a "trash tree".
Heisey, R. M. and Heisey, T.K. 2003. Herbicidal effects under field
conditions of Ailanthus altissima bark extract, which contains
ailanthone. Plant and Soil 256: 85-99:
Ailanthone is rapidly inactivated in nonsterile soils so its actual
allelopathic effect under field conditions may be less than what
artificial lab experiments with unnaturally high doses indicate. The
structure of ailanthone is given here:
You might just try extracts of whatever evergreen leaves you have
available and see if they inhibit seed germination.
Here's a study that found allelopathic effects from water extracts of
evergreen leaves of Rhododendron maximum:
Evergreen yew leaves might contain allelopathic chemicals:
Juglone, an allelopathic compound, is found in roots of black walnut:
There are reports that broccoli has allelopathic effects:
The hulls of sunflower fruits are allelopathic:
What effects does Ailanthus extract have on your seedlings? Perhaps you
could use some type of herbicide. Ailanthone effects have been
compared to the herbicides paraquat and Round Up.
Table salt or sucrose inhibit seed germination. Precollege students
often use sugared soda pop in place of irrigation water and find it
kills their plants or seeds. Although essential for plants, boron (as
drugstore boric acid), is very toxic to plants at fairly low
concentration (a few ppm of B).
David R. Hershey
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