Alfalfa
Diseases in Ohio
Spring
black stem
- symptoms
- found early in the
season
- leaf and stem lesions
are small, irregular, dark brown to black spots
- chlorosis and death
of tissue
- lesions from large
blackened areas on stems which may crack and split
- plant growth stunted
- Environment
- cool, wet weather
- temperatures of
60-70°F
- Survival
- fungus overwinters
and oversummers in alfalfa stubble
- spores splashed
on young leaves and stems
- Management
- proper soil pH
- proper fertility
- proper harvest intervals
- Scouting
