Scouting for Disease: Tar Spot

Jun 26, 2024


Tar spot on corn
Cool, humid conditions with long periods of leaf wetness – a.k.a., the substance of this early growing season – create the “ideal environment for tar spot,” said Brad Hipsag, Federated ag sales rep out of Ogilvie. And, corn that was planted later is developing later, too, giving tar spot infections time to occur (as compared to “crops planted more timely,” said Hipsag).
 
“Tar spot is a leaf disease that makes black spots on leaves and can cause significant yield loss in corn under the right environments,” said Hipsag. Tar spot symptoms look like specks of black tar on the leaf, starting as brown lesions and leading to black spores that protrude from the leaf. The spots “will feel bumpy and will not rub off,” he said.
 
Though symptoms of tar spot can develop at any growth stage, the signs typically develop most severely in late summer. Your Federated Agronomist can submit a leaf sample for diagnostic testing to confirm the presence of tar spot.
 
Federated recommends fungicides to combat tar spot; other control strategies include crop rotation and choosing hybrids bred for tar spot tolerance. “Start scouting now,” said Hipsag, “for diseases, insects, and nutrient deficiencies in corn.”

Read More News

Jul 17, 2024
The cover crop planting window is open. Take time to consider all of your many options.
 
Jul 17, 2024
The temperatures are right for crop insects, and although moisture is a deterrent, it's no guarantee that the bugs aren't getting to the crops. Keep scouting for these pests.
Jul 17, 2024
As we arrive at the mid-point of the season, it’s good to know what your Federated Agronomists see and note across their service areas.
 

Related Topics