Rhizoctonia stem rot

rhizoctinia on young plants
Rhizoctonia stem rot: brown lesions on young plants
Cause

Rhizoctonia solani

Damage

Rarely causes problems under traditional dryland peanut production conditions in Australia. May be a problem under sprinkler irrigation where the soil surface stays cool and moist. Plants can be killed from seedlings to maturity.

Symptoms

Distinctly zonate brown sunken lesions which can completely girdle stems, causing part or all of the plant to die. Pegs and pods may also be affected.

Spread

The fungus is already present in many soils and can survive in soil for many years.

Management options

Cultural
Very little can be done, except to irrigate so that the plant is wet for the least possible time.

Applying gypsum may reduce pod rots. Avoid covering the crown and branches of the plant with soil during cultivation.

Rotate crops to increase or maintain levels of soil organic matter.

Chemical registrations and permits
Check the Australian Pesticides and Veterinary Medicines Authority chemical database and permit database for chemicals registered or approved under permit to treat this disease on the target crop in your state or location. Always read the label and observe withholding periods.