Seedling Failure in Atriplex (Chenopodiaceae) Due to “Damping-Off.”

Abstract

Repeated failures in attempts to establish a selection of Atriplex in a non-mined site near the Navajo Mine in New Mexico proved to be due to "damping-off" (black root) of the seedlings, caused by Pythiaceae fungi. The contaminated soil contained more than 1,000 propagules of the fungus per g of soil; stockpiled soil in another area contained an average of 20 propagules per g of soil. Coating the Atriplex seed with fungicide prior to sowing increased seedling establishment more than JOO-fold. Reduced vigor and loss of plants subsequent to seedling-establishment may also be caused by these fungi.