Sunflower rust

Early symptoms on volunteers and seedlings appear as small, orange-brown spots on the upper surfaces of leaves, followed by spots appearing on the lower surfaces of leaves. A heavy infection can cause the entire leaf to die. Rust spots may also be found on the stems, petioles, bracts and back of the head. In late July or early August, rust appears as dark-brown, dusty pustules on surface of the leaves, leaf petioles and the back of heads. This is the most damaging stage of rust infection during the season.  The black pustules of over wintering spores will be found on all plant parts towards the end of the season.