Pythium and Fusarium in Potatoes

Nathan Kleczewski, Extension Specialist – Plant Pathology; nkleczew@udel.edu

Nancy Gregory received several samples of potatoes over the last 10 days that were affected by Fusarium and Pythium, which can cause tuber rot and impact seed quality. Wounding at harvest can facilitate infection by these pathogens, as can swelling and enlarged lenticels.

Potato plants can compensate for stand losses of approximately 3%, and seed is very limited this season. Therefore, there is no guarantee that subsequent lots will be any better in terms of quality. If you have low levels of these pathogens in your potatoes or do not want to roll the dice on a new load and potentially delay planting, an in furrow application of Ridomil Gold + Quadris will help minimize any additional issues with these diseases during the growing season. As always, make sure to save your seed certification certificate and lot number for future reference.

Pythium and Fusarium can cause severe tuber rot in some cases.