A fungal disease which affects the
leaves of
daylilies.
It is caused by
Aureobasidium microstictum*, however an
injury to the plant may be required for infection to take place
-
pest damage, for example. Symptoms
include yellowing along the central leaf vein followed by browning,
and reddish-brown spots. The damaged areas may join together
and spread along the leaf in streaks, and infected leaves may
eventually die.
Cultivars vary in
their susceptibility to leaf streak. Minimize overhead watering
and avoid working among the plants when the leaves are wet.

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LEFT: Leaf
Streak close up
BELOW: Leaf Streak infected foliage. |

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Above
photos by Doug Maxwell, used with permission.
Photo
below is by Sue Bergeron, used
with permission. Note below
that the affected part of the
leaf is the center midline vein
then outward as the disease
progresses.
 |
*Aureobasidium microstictum is the current name given to the daylily leaf streak fungus, but it has had several name changes and may be listed in literature as
Kabatiella microsticta,
Gloeocephalus hemerocalli or
Collecephalus hemerocalli.
For more information:
Florida Dept. of Agriculture Circular 376, Daylily Leaf Streak by Leahy and Schubert:
http://www.freshfromflorida.com/content/download/9808/135116/pp376.pdf
"Control of Leaf Streak on Daylilies with Fungicides" by Kirk et al.
http://www.sar-headsup.com/trials/daylily/Day_Lily_article_MDFGA_2002.pdf