Cotton root rot is caused by a soil-inhabiting fungus pathogen that attacks a wide range of host plants including pecan. Roots of pecan tree can be invaded at any time except during the coldest months of the year. The fungus is most active during the mid to late summer months. Infected roots are killed, disrupting the transportation of water to the leaves. Diseased trees die soon after becoming infected.
Losses continue several years after planting.
The losses increase in numbers roughly in porportion to the increasing size of the disease center. The fungus is present in many alkaline soils in central and south Texas. An effective control for cotton root rot has not been developed. Do not plant in soils that have had a history of cotton root rot. Nuts affected by this disorder drop from one to two weeks early.