Tuesday, May 13, 2008

Landscape - Volutella Blight of Pachysandra

Volutella blight is a common disease of Pachysandra in Delaware. The following is information on this disease in the landscape.

Volutella blight (also called Pachysandra leaf and stem blight) is easy to spot. Plants infected with the fungus Volutella exhibit characteristically large, “bulls-eye” leaf spots and elongate cankers on petioles and stems. Within several weeks, highly diagnostic, pink-colored fruiting bodies form on affected tissue. This disease can be very destructive in beds, causing circular patches of dying plants to form and enlarge rapidly. Like many diseases in the landscape, Volutella blight cannot be sufficiently managed by only using fungicides. There are cultural factors that contribute to disease severity. First, water is essential in the disease infection process, so “managing the moisture” helps to manage the disease. Avoid practices that encourage excessive moisture (such as including heavy mulching and over watering). Periodically thin the beds to increase light and air circulation. Avoid watering during times of the day, such as late afternoon, when the beds are apt to remain wet for long periods. Consider that heavy shade may also contribute to longer periods of leaf wetness. Winter injury and wounding predispose pachysandra to this disease. Common things to watch out for include mechanical injury (foot traffic, pets, or children playing in beds), scale insects, and poor nutrition. Fungicides labeled for control of this disease include chlorothalonil, copper (Badge, hydroxide, metallic, oxychloride, salts, sulfate), Junction, mancozeb, Spectro, or Zyban. Please follow label directions when applying pesticides.

Volutella blight on Pachysandra. Photo by Jody Fetzer, New York Botanical Garden, Bugwood.org

Reprinted from "Diseases of Landscape Ornamentals in the Springtime, Part II" by Ann B. Gould, Ph.D., Specialist in Plant Pathology, Rutgers University in the April 17, 2008 edition of the Plant and Pest Advisory, Landscape, Nursery, and Turf Edition, from the Rutgers New Jersey Agricultural Experiment Station - Cooperative Extension.

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