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ArticleBrownfield Ag NewsJul 16, 2026

Is Tar Spot Pressure Rising for Iowa Corn Growers?

Iowa corn growers are increasingly concerned about rising tar spot pressure this season.

AI-generated source brief by USFarms.ag, based on Brownfield Ag News. How our briefs are made

Source published Jul 16, 2026. Check the source date before applying seasonal guidance. Brief published .

crop diseasestar spotcorn management

Source summary

What this article covered

Rising Concern Among Growers

Iowa corn growers are increasingly vigilant as tar spot detections rise this season. The presence of this fungal disease, although currently low in severity, is prompting discussions about potential impacts on crop health.

Current Severity Levels

Meaghan Anderson from Iowa State University reported that the severity of tar spot remains low, but the number of confirmations is a cause for concern. This could indicate that the disease is becoming more prevalent.

Implications for Crop Management

As tar spot pressure increases, growers may need to adjust their management strategies to mitigate potential yield losses. Understanding the disease's development will be key to effective crop management.

Key takeaways

5 things worth knowing

  1. 01

    Tar spot confirmations in Iowa are increasing this season.

  2. 02

    Most detections are low on the plants with low severity.

  3. 03

    The trend could indicate future challenges for corn yields.

  4. 04

    Growers need to monitor the situation closely.

  5. 05

    Understanding tar spot's development is essential for management strategies.

Questions & answers

Quick answers

What is tar spot?

Tar spot is a fungal disease that affects corn plants, causing dark spots on the leaves.

How does tar spot impact corn yields?

While current severity is low, increased pressure from tar spot can lead to reduced yields if not managed properly.

What should growers do if they detect tar spot?

Growers should monitor the disease closely and consider management strategies to mitigate its impact.

Is tar spot a new concern in Iowa?

No, but its increasing presence this season is raising alarms among growers.

What are the signs of tar spot?

The disease is characterized by dark, tar-like spots on corn leaves, typically starting low on the plant.

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