Cylindrocladium-dieback of box - Cylindrocladium buxicola
Symptoms / species
Impact / measures
Dark brown spots on leaves, coalescent to broader, brown and later on grey areas; excessive loss of leaves; on the stems and twigs thin, elongated, blackish-brown discolored stripes, later on cracking open; decline of leaves, branches and the whole plant.
Affected tree species
Leaf; Stem; Shoot/Twig/Branch;
Cylindrocladium buxicola has been discovered at the beginning of the Nineties in the UK and in New Zealand. It causes heavy damage on box (Buxus sempervirens and other species). The disease has been spreading recently in several states of continental Europe, attacking box in the urban green, in gardens, in nurseries and in graveyards. It occurs both on prestressed and non stressed plants, infection does not require mechanical lesions. The disease can be spread over long distances with infested plant stock, over shorter distance by wind and rain as well as pruning tools. In addition to box, Christmas box (Sarcococca humilis) is susceptible to >em>Cylindrocladium-infection.
Possibility of error: Volutella-dieback of box.
Curative measures For a precise diagnosis samples of diseased box with suspicious symptoms should be sent to a diagnostic lab.
Control can be achieved primarily by hygienic measures: removal of diseased plants and plant material; soil change (the disease is able to survive in the soil by resting spores; use of resistent or less susceptible cultivars, avoidance of any stress for the plants, disinfection of pruning tools.
There is not much experience with chemical control, some combined fungicides showed effects against spore germination and mycelial growth (see special literature).
Cylindrocladium buxicola: box dying back
Cylindrocladium buxicola: partly discolored leaf
Cylindrocladium buxicola: stem with elongated dark stripe
Cylindrocladium buxicola: masses of spores on a leaf (moist chamber method)