Gangrene
Phoma exigua var. foveta
Phoma exigua var. foveta
Fungus
Potatoes
Small dark `thumb print` depressions in the tuber skin. The rot inside the tuber is usually surrounded by a black / brown margin.
The disease originates from inoculum on seed tubers, which subsequently infects the surrounding soil. Daughter tubers are infected through wounds caused during lifting. Rotting develops during storage at the wound sites and usually becomes apparent in December or January.
Favourable Factors
Dry, cold lifting conditions followed by cool storage. Tubers become more susceptible as they age.
Can result in serious storage losses.
Find out more information on the key disease threats to your potato crop. For each disease you will find out the importance of the disease in terms of potential yield penalty, how to identify the disease in its early stages and our advice on the best control strategies.