The
Other Stalk Rot: Pythium Stalk Rot
There has been a few incidence this year
of some corn plants that remained green even though they had lodged. In
fact they stayed green for up to three weeks before eventually dying.
The cause was Pythium stalk rot which is not all that common in Ontario.
Why the "stay-green"? The most likely reason is that although
the rind and pith was disintegrated (brown, soft and watery) near the
first node or base of the plant, the nutrient and water conducting (vascular)
tissue was not destroyed by the fungus. Your nose can be used in the diagnosis
since infected plants will often have a strong rotting odour as the tissue
decays or rots.
Pythium is a water loving fungus and we all know that moisture was not
limiting this year. Quite the opposite. Add the cool to warm temperatures
and you have the ideal conditions for Pythium development.