Risk factors

The development of this pathogen is favoured by high soil humidity and moderate to elevated temperatures.

Pythium spp. develops mainly during hot periods and infect the tubers, especially after hot stormy weather at harvest time, by penetrating through wounds or open lenticels. If the harvested tubers are not dried sufficiently, tuber damage may be severe and lead to tuber or lot leaking.

Monoculture or intensive potato production, added to favourable environmental conditions and the presence of primary sources, may increase the severity of the disease.