Divisi
Sorghum head smudge
Curvularia lunata · Fungal
Photo: Chris Light · CC BY-SA 4.0
Head smudge is a fungal disease of the sorghum head, caused mainly by Curvularia lunata and its relatives. Under warm, wet, humid weather at flowering and grain fill, the fungus colonises the glumes (the little husks that wrap each grain) and the grain surface, leaving a dark, sooty smudge. It rarely destroys the grain outright, but it dirties and downgrades it, and seed saved from smudged heads sprouts poorly. It usually travels with the wider grain-mould complex.
Mohanapourani Hort · CC BY-SA 4.0 
Chris Light · CC BY-SA 4.0
Why it matters
Head smudge attacks the grain itself, right at the end of the season when you are almost home. In a bad, wet year it can dirty and downgrade up to a third of your harvest (about 30%) — buyers pay less for smudged, sooty grain, and it stores worse. It is hard to fix because the damage appears on the mature head, when it is already too late to save that grain; and if you keep seed from smudged heads, much of it will not sprout next season, so the loss follows you into the next crop.
When to act
Wet, humid weather during flowering and grain fill on a susceptible open-panicle variety; darkening grain appearing on maturing heads.
This guidance is general, compiled from published agronomic references including FAO and CABI. Thresholds and timing shift with your crop, your variety and the season.
In much of the region a spray is simply called mushonga — medicine. But a chemical group you cannot name is one you cannot rotate, and a product you did not write down has no pre-harvest interval you can observe. Mushonga, and other farming words →
The full sorghum head smudge field guide
- Identify it
- Scout for it
- Control it
13 field-guide sections in the app
The full guide to sorghum head smudge — every symptom to check, how and when to walk your field looking for it, and the controls that actually work, ranked. Built into your crop plan, so you are told to look before it costs you a harvest.
Crops it affects
Frequently asked questions
How do I identify sorghum head smudge?
The damage first: as the heads ripen, watch the grain turn dirty instead of clean. Healthy grain colours up bright and even; smudged grain looks sooty and smeared, as if someone rubbed the head with a thumb of ash or soot.
When should I take action against sorghum head smudge?
Wet, humid weather during flowering and grain fill on a susceptible open-panicle variety; darkening grain appearing on maturing heads.
How do I control sorghum head smudge?
Prevent first — choose the right variety (your strongest tool): plant tolerant varieties with tight glumes and coloured (not white) grain. Tight husks keep the fungus off the grain and coloured types resist head smudge and grain mould far better — this is the single most effective step you have.
Which crops does sorghum head smudge affect?
Among the crops covered here: Sorghum, Teff.
Catch it before it costs you a harvest
Divisi builds scouting into your crop plan — it tells you when to walk your field, what to look for at that stage, and what to do when you find it. Free for farmers, works offline.
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