Stenocarpella ear rot

Stenocarpella ear rot, commonly referred to as Diplodia ear rot, is caused by the fungus Stenocarpella maydis. It is a significant disease affecting maize production globally, leading to substantial yield losses and reducing grain quality due to the rapid decay of ears and potential accumulation of mycotoxins.

The primary host for this pathogen is maize (corn). The fungus survives in crop residues left on the soil surface, making it particularly problematic in no-till or reduced-tillage systems. The pathogen can remain viable in debris for several seasons, providing a persistent source of inoculum for subsequent crops.

Symptoms typically begin at the base of the ear, characterized by a dense, white mycelial growth spreading between the kernels. As the disease advances, the entire ear may become brown, lightweight, and brittle. Tiny black specks, known as pycnidia, frequently appear on the husks and the base of the stalk, signaling the pathogen's reproductive stage.

The development of the disease is highly dependent on environmental conditions, particularly high humidity and warm temperatures during the silking and grain-filling stages. Spores are dispersed via rain splashes and wind, infecting plants primarily through the silks or the base of the ear during wet periods in late summer.

Effective management requires an integrated approach. Recommended strategies include rotating crops with non-host species, burying crop residues to accelerate decomposition, and selecting corn hybrids with genetic resistance or tighter husk coverage.

• Select resistant corn hybrids
• Practice crop rotation
• Tillage to bury residues
• Timely fungicide applications
• Monitor field moisture levels