Rhizoctonia Root Rot and Sharp Eyespot (fungus - Rhizoctonia solani): Many Rhizoctonia strains infect wheat roots and culms. Culm infections are sometimes observed in North Central and East Texas. These are referred to as sharp eyespot. Sharp eyespot begins as a gray colored lesion on the lower leaf sheath. Lesions may later turn straw colored. Acid, sandy and dry soils increase disease risk as do cool spring temperatures. Bare Patch of wheat is also caused by a particular strain of Rhizoctonia solani. This disease has not yet been identified in Texas.