The lesion enlarges with time and penetrates into the stem. The sheath is weakened and plants can lodge. The sclerotia float on the water and attach themselves to infected rice sheaths.
More infection occurs when the rice sheath is injured.
Addition of potash or sodium silicate can reduce disease. Natural lodging increases disease. Stem borer damage increases disease. There are measurable differences in varietal resistance to Sheath Rot. The Extension Service publishes the Stem Rot reaction of the varieties grown in Mississippi.