Daylily Leaf Streak
Tuesday, 07 June 2005 10:50
Daylilies may become infected with a foliar disease known as yellows disease or daylily leaf streak caused by the fungus Aureobasidium microstictum. Small, reddish-brown flecks and brown spots develop on infected tissue. You may then see a central yellow streak along the midvein that begins at the leaf tip. If severe, entire leaves can turn yellow. However, daylily leaf streak does not affect daylily flowers. Different cultivars will vary in how susceptible they are to this fungal disease. Nutritionally and water stressed daylilies are also more susceptible to this disease than healthy, vigorous plants.
Fungal spores are released when the foliage is wet and are spread by splashing water. Water early in the day so leaves can dry. Keep plants as well-spaced as possible to increase air movement around plants. Several different fungicides are labeled for leaf spot diseases including thiophanate methyl (Cleary's 3336 or Fungo Flo), myclobutanil (Eagle), or chlorothalonil (Daconil, Pathguard) or azoxystrobin (Heritage). Consult and follow fungicide labels for registered uses. Some materials are labeled for greenhouse use only, some for outdoor nursery use and some may have geographic restrictions. Many fungicides are labeled for only a limited number of perennial species. To avoid any potential phytotoxicity problems, spot test first before widespread use. At the end of the season, remove infected leaf debris. Do not confuse this fungus disease with Daylily Rust.
Photo: Daylily leaf streak
See the following fact sheets and web sites on Daylily Rust and Daylily Leaf Streak.
Daylily Rust
Pest Alert: Daylily Rust
Photos of Daylily Leaf Streak from The American Hemerocallis Society
Leanne
