Stenocarpella macrospora, syn. Diplodia macrospora

Nature of damage

• This disease has not been reported to cause economic damage, but causes some damage in commercial maize plantings.
• Stenocarpella macrospora is mostly an ear-rotting agent, but under appropriate climatic conditions can cause foliar damage.

Signs

• Symptoms consist of necrotic lesions along the veins. These lesions resemble spotting produced by bacteria or by Exserohilum turcicum (leaf blight).
• When held against the light, S. macrospora lesions exhibit a distinct narrow yellow margin not present in lesions caused by other pathogens.
• Under humid conditions, the black, spore-producing pycnidia formed in the necrotic lesions ooze spores in fine black threads and the lesion splits.

Geographic distribution

• Found in hot, humid areas.