back to HYPP Pathology
home page

Mycologia, DEUTEROMYCOTINA, HYPHOMYCETALES, TUBERCULARIACEAE .

Crops attacked: lettuce .

Ring spot,

Identification, Description, Biology, Epidemiology, Treatement, Possible misleading, Images

[R]Description
This disease mainly attacks the young plants. Large numbers of tiny round to angular yellow spots (3 - 5 mm diameter) occur on the outer leaves, then become necrotic and dark.
The necrotic spots may fall off and leave holes in the leaf.
The whole crop can die when contamination is high.

[R]Biology
The fungus survives in the debris.
Weeds, compositae in particular, are a source of inoculum. The disease can also be seed-borne.
Conidia form at the center of the necrotic spots.

[R]Epidemiology
Cold humid conditions facilitate the outbreak of the disease.
Contamination from plant to plant can occur through splash which carry conidia on water drops.

[R]Treatement
Steady rotations recommended.
Use disinfected or treated seeds.
Trim and burn all outer leaves covered with spots.
Apply fungicide treatments according to local practice.

[R]Possible misleading
.

[R] Images

1. Marssonina panattoniana , Anthracnose, Ring spot (BASF)
   Anthracnose, Ring spot on lettuce Yellowish-white round lesions coalescing to form necrosis on a lettuce leaf infected by anthracnose.
   

To read this page in French

HYP3 on line : Species (scientific name), Diseases (common names), Glossary, Crops.

back to HYPP Pathology home page