|
|
Alfalfa
> Year-Round IPM Program > Summer > Identifying
Disease
Alfalfa
Identifying Diseases and Disorders—Summer
On this page
- Phytophthora root and crown rot
- Rhizoctonia
- Scald
|
- Southern anthracnose
- Stagonospora crown and root rot
|
Several diseases and disorders occur in alfalfa
in the summer. Compare field symptoms to the photos below and
keep records of diseases you see. Adjusting irrigation practices
can reduce some diseases and disorders. Names link to more information
on identification and management.
Click on photos to enlarge
| Field view |
Close-up view |
Phytophthora root and crown rot
Identification tip: Leaves of infected plants turn
yellow or tan and drop. Phytophthora can infect large
areas of alfalfa in a field.
|
Phytophthora root and crown rot
Identification tip: Red-orange to yellow streaks spread
up from infected root tips.
|
No photo available. |
Rhizoctonia Root Canker
Identification tip: Brown rotted roots caused by
seedling disease known as damping off, due to Pythium sp., Rhizoctonia sp.,
or Fusarium sp.
|
Scald
Identification tip: Plants that sustain waterlogging
combined with high soil temperatures will uniformly turn
yellow and wilt. This condition, called scald, can also occur
with soils that remain saturated for long periods under cooler
temperatures.
|
No photo available.
|
Anthracnose
Identification tip:
Infected
plants' stems eventually become bleached and bent. |
Anthracnose
Identification tip:
Southern
anthracnose stem lesions (right) are darker and lack the
distinct fruiting bodies that appear in Stagonospora lesions (left). |
Stagonospora crown and root rot
Identification tip: Stagonospora leaf spots are irregularly shaped tan lesions
with brown borders.
|
Stagonospora crown and root rot
Identification tip: Stagonospora
lesions are spotted with tiny, round, black fruiting bodies.
|
|
