Preliminary studies of boxwood blight

Abstract

A disease of boxwood, so called "boxwood blight", began causing serious damage to boxwood plants after·the drouth of 1930.

Four fungi were isolated from the affected parts of diseased plants. Macrophoma candollei waa isolated from the leaves, a species of Fusar1a from diseased stems and twigs, a species of Coniothyrium from the cankers on the stems, and a species of Verticillium from the infected roots.

Inoculation experiments were performed on healthy young boxwood plants that were growing in the greenhouse. Pure cultures of Fusaria, Coniothyrim, and Verticillium were used as inoculum. In general the results were negative. The Fusarium culture was the only one that produced any infection and that infect1on waa very slight.

Observations made of infected plants in the greenhouse at V.P.I. and at a nursery at Marion, Virginia, and. also a nursery at South Boston, Virginia, indicate that probably the fungi associated with boxwood blight, infect only thoae plants that have been weakened by some physiological condition such as lack of moisture, winter injury, malnutrition, insect injury, or improper transplanting.