Late blight infection at the base of the stem initiated by infected seed This symptom looks similar to blackleg see page 87 In humid weather no white mycelium develops on plants infected with blacklegLate blight symptoms on stems are irregular dark brown to black lesions Under humid conditions fungal mycelium and spores develop on infected areasStem lesions expand rapidly in humid weather and can cover most of the stemInfected stems are brittle and break easilySeed ball infected with late blightThe right half of the field was killed by late blight Note the regrowth of healthy shoots after the infected plants diedThe tender growing point is an easy target for late blight because moisture persists there after a heavy dew rain or irrigation
