Southern corn leaf blight
Small tan to brown oblong spots between the leaf veins that join into large dead patches across the leaf.
Crops it strikes
What you see
When to act
In hot, wet weather, check the lower and middle leaves on 20 plants at each of five spots every week from the 8 leaf stage. Spray a susceptible hybrid when spots climb from the lower leaves toward the ear leaf before silking. After the dough stage a spray does not pay.
What to spray
- Difenoconazole plus propiconazoleFRAC 3 plus 3ShopeeLazada
- Tebuconazole plus trifloxystrobinFRAC 3 plus 11ShopeeLazada
- ChlorothalonilFRAC M05ShopeeLazada
- MancozebFRAC M03ShopeeLazada
- AzoxystrobinFRAC 11ShopeeLazada
Active ingredients only, never brands. The FRAC group tells how it works: switch to a different group next time, so the disease does not learn to survive it. Spray only when the damage is worth the cost, and only with products registered with the Fertilizer and Pesticide Authority for your crop. Follow the label. The Shopee and Lazada links only show who sells something with that active ingredient, not a recommendation of any seller or product.
How to prevent it
- Plant a resistant hybrid. It is the main control in hot, wet lowlands.
- Plow under or remove corn residue after harvest, where the fungus survives.
- Rotate with a crop that is not a grass, and clear volunteer corn.
- Feed balanced nitrogen with enough potassium. Weak, hungry plants blight faster.
- Avoid planting so late that the crop flowers in the hottest, wettest weeks.
Not sure it is this one?
Many diseases look alike. Send a photo to Anee, the smart farm technician in anee.io. She reads it with your crop, its age and the weather, and tells you what it most likely is and what to do first. In Tagalog or English.