January 2012. A taro corm rot seen at harvest in Fiji.

A member wrote that it was almost impossible to diagnose taro corm rots based on symptoms alone, but the cause is most likely Pythium. This is a soilborne organism, and the disease that it causes is helped by very wet conditions. There is little than can be done about the problem other than use clean planting material and plant into new land or land that has not grown taro or ginger for some time.

There was a suggestion to use Trichoderma harzianum; it was said to have given good results against Pythium on tobacco and ginger in India.