Damage due to excess water
Too much water damages the potato plant and injuries can take different forms:
- Wet rot
If the potato plants are waterlogged (by flood) for a period greater than 24 to 36 hours, the tubers are asphyxiated and become prone to attacks from various latent micro-organisms in the soil (Pectobacterium, Pythium, and Phytophtora erythroseptica). Potato tubers in the bottom of the mound are more exposed than the others (photos 1, 2 and 3).
In certain rare cases, black heart may be observed.
- Enlarged lenticels (lenticellosis)
A high soil moisture content lasting for several days favours lenticel enlargement on the tubers.
This alters their appearance at harvest time and favours penetration by rotting agents.