Initial symptoms of "P. helianthi" infection can be found at the attachment of petiole to the stem on the lower portion of the plant. Initial infection will cause brown necrotic regions with a chlorotic border. Eventually these regions will grow into larger, brown to tan lesions and eventually into large cankers. Cankers are found on the stem and will have a sunken border. Cankers can be long, up to 6 inches, but do not appear until flowering. Other early symptoms can include necrosis and bronzing of intervenial areas of leaves at or above the stem lesion. Wilting and death of leaves above the canker also occurs. Leaves above the site of inoculation can also show symptoms of being water soaked. This is sometimes accompanied by leave distortion. "Phomopsis" stem canker is also characterized by extensive pith degradation to the point where the stalk is easily crushed under moderate thumb pressure. Wilting is also a typical symptom, and extensive wilting can eventually lead to lodging later in the season. "Phomopsis" also produces mycotoxins, which can cause additional symptoms such as premature ripening or early plant death.