Bermudagrass Leaf Rust

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It’s not unusual for us to be dry in October. But it is unusual to go into October already dry. Many folks have not seen one measurable rain in the month of October. As we walked through this Alicia hay field, our boots were covered in rust spores. Clouds of rust were seen with each step. Leaf rust this time of year is pretty typical in Alicia. We may not see it exactly this bad with Coastal.

Identification

Will rust, you will see red to orange lesions on the leaf and stem. Look for a raised area or blister which is the rust postules like we see in wheat and corn. Rubbing your finger over the leaf will leave a rusty color.

Leaf Rust

Leaf Rust

Leaf Rust

Postules of rust are raised

Management

We cannot use fungicides on our hay fields, so management is strictly avoidance. Coastal, Tift 44, and Tift 85 have some level of resistance while Alicia is extremely susceptible. But even less susceptible varieties are infected with leaf spot when POTASSIUM is low. Most reported leaf spot cases are directly related to low soil potash. Nutrients are removed from bermuda hay fields in about a 4-1-3 ratio of N, P2O5, and K2O with harvest. We need 75 percent as much potash as nitrogen  applied each season. Split applications of K are better in sandy soils. In these cases, nearing the end of the season, we need to go out with another shot of straight potassium.

Visit Leafspot Diagnosis and Management in Bermudagrass Forages for more information.

Leaf rust on boots

Leaf rust on boots

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