The primary symptoms for this disease include the presence of large dark black lesions on stem which originate from the attachment point of the petiole. Lesions may cause the wilting and blackening of leaves. Infection weakens plants and they may have reduced yields. The disease has been associated with so-called premature dying of sunflowers. Phoma Black Stem has not generally been a target for management, due to its sporadic nature.
Some cultivars are more tolerant.
Recurring disease can be managed through control on weevils and rotation Return to Outline Phomopsis Stem Canker Phomopsis Canker is distributed throughout the Central Plains states, and is a much more serious problem than Phoma Black Stem. It is associated with much more damage to stalk tissue than Phoma. Sunflower Production .