Master Gardeners: controlling and avoiding Botryosphaeria Disease

This is Steve Rulison bringing you information on Shore friendly living and gardening from the Eastern Shore Master Gardeners and Virginia Cooperative Extension.  From my perch near the mouth of Occohannock Creek, I recorded virtually no rain last week.

Today we will be sharing some information on controlling and avoiding Botryosphaeria Disease. 

Most trees and shrubs are susceptible to dieback and cankers caused by several species of the fungal genus Botryosphaeria. Botryosphaeria fungi are typically “Opportunistic” pathogens. Opportunistic pathogens only cause disease on plants that are stressed. Therefore, avoiding plant stress, which predisposes plant tissue to infection and colonization by this fungal group, is the best strategy to prevent Botryosphaeria disease problems.

Symptoms of Botryosphaeria cankers and dieback are most commonly seen as wilting, or dieback, of a branch or branches on a tree or shrub that, in other respects, appears healthy. Cankered twigs and branches may not be noticeable until wilt and dieback occur. However, if bark is removed, the wood beneath the bark will be discolored brown to reddish-brown instead of white.

In some cases, cankers may appear sunken and/or darkened or be surrounded and contained by callused wound wood, particularly on larger branches or trunks. In other cases, bark may peel and drop from cankered areas.

There are no effective fungicide controls for Botryosphaeria dieback. The best defense against this commonly occurring disease is to ensure plants are in optimal health by providing the appropriate cultural requirements for the particular plant species, avoiding plant stress and injury, and employing appropriate sanitation measures.

It is important to remember that under optimal growing conditions, trees and shrubs are typically able to resist infection and colonization by Botryosphaeria fungi. 

For answers to Gardening questions and more, call your local Accomack or Northampton County Extension Office. Here on the Shore call either 678-7946 or 787-1361.