Aster yellows has wide host range. Starts as soft, water-soaked spot on stem near soil surface and spreads upward and downward. Plant in well drained soil. Avoid ground where cabbage or celery have been grown. Symptoms appear on oldest leaves first.
Spots begin as light-green areas on upper side of leaves.
Soon followed by white mold on underside of leaf. Plants become yellowish and dwarfed. Fungus over winters in residues and in wild lettuce plants. Plant in well-drained soil. Apply foliar fungicide at 7-10 day intervals after disease first appears.