|
Principle
|
IPM
Practice
|
| Microdochium
panatonnianum persists in soil for long periods of time |
Rotate
out of lettuce, 2 to 4 years |
| Sanitation
is needed throughout transplanting operations |
Treat
benches and seedling trays with a dilute bleach solution;
remove and destroy infected seedlings promptly; sterilize
soil with steam, if available |
| Cultivars
respond differently |
Romaine
and head lettuce types are more susceptible than green leaf,
bibb, or red leaf types |
| Foliar
fungicides need to be used preventively when weather conditions
are favorable or when disease is first noted in the area |
Azoxystrobin
fungicides have some efficacy and are in the process of
being registered
Maneb
75 DF at 1.5 to 2 pounds per acre is registered for downy
mildew control on lettuce and gives some anthracnose control,
unless disease pressure is severe; a total of 12.8 pounds
product per acre are allowed per year; no applications
are allowed within 10 days of harvest; potential residues
need to be removed from head lettuce by stripping and
trimming
|
