Southern Rust has been Reported in Additional Counties in Kansas

Aug 05, 2021

By Rodrigo Borba Onofre

Southern rust was just confirmed in Reno and Sedgwick counties in Kansas (Figure 1). Southern rust was first detected in southeast Kansas on July 2, and we continue to monitor the spread. At present, levels have remained low, however recent weather has been favorable for the disease in some parts of the state. Early detection of southern rust is crucial for successful management. Once pustules have been observed, the pathogen can reproduce rapidly if temperatures and humidity are high. Late-planted corn should be monitored closely, as the crop will be exposed to southern rust for a longer period than corn that was planted earlier.

Southern corn rust

Figure 1. Southern corn rust (Puccinia polyspora) in Kansas and surrounding states as of July 15, 2021.

Considerations for treatment of southern rust

When deciding to spray for southern rust it is important to consider hybrid susceptibility, disease incidence (how many plants are affected), and corn growth stage. Infection early in the season on a susceptible hybrid, coupled with conducive weather conditions, pose the highest risk for yield loss.

Research has suggested that applications between VT to R3 have great potential for protecting corn yield, however if fungicide is applied between VT and R1, a second spray may be required to protect end of season yields. Most fungicides that are labeled for southern rust are also effective for gray leaf spot and will have residual activity for approximately three weeks after application, depending on the product. Application at dent (R5) are unlikely to provide yield benefit and the pre-harvest interval should be carefully observed. Fields that have not yet been sprayed should be monitored for disease development.

Efficacy ratings for corn fungicide management of southern rust have been compiled by a working group of corn researchers and can be found here: https://cropprotectionnetwork.org/resources/publications/fungicide-efficacy-for-control-of-corn-diseases

Identification of southern rust

Southern rust produces characteristic orange pustules filed with spores, primarily on the upper side of the leaf (Figure 2). If you run your finger across the pustules, the orange spores will be visible on your hand. The Kansas State Plant Diagnostic Lab (clinic@ksu.edu) can also confirm southern rust by observing spores under the microscope. Additional information about sending in a sample can be found here: https://www.plantpath.k-state.edu/extension/diagnostic-lab/.

Southern rust on corn

Figure 2. Southern rust on corn.

Source : ksu.edu

Video: From Conventional to Regenerative: Will Groeneveld’s Journey Back to the Land

"You realize you've got a pretty finite number of years to do this. If you ever want to try something new, you better do it."

That mindset helped Will Groeneveld take a bold turn on his Alberta grain farm. A lifelong farmer, Will had never heard of regenerative agriculture until 2018, when he attended a seminar by Kevin Elmy that shifted his worldview. What began as curiosity quickly turned into a deep exploration of how biology—not just chemistry—shapes the health of our soils, crops and ecosystems.

In this video, Will candidly reflects on his family’s farming history, how the operation evolved from a traditional mixed farm to grain-only, and how the desire to improve the land pushed him to invite livestock back into the rotation—without owning a single cow.

Today, through creative partnerships and a commitment to the five principles of regenerative agriculture, Will is reintroducing diversity, building soil health and extending living roots in the ground for as much of the year as possible. Whether it’s through intercropping, zero tillage (which he’s practiced since the 1980s) or managing forage for visiting cattle, Will’s approach is a testament to continuous learning and a willingness to challenge old norms.

Will is a participant in the Regenerative Agriculture Lab (RAL), a social innovation process bringing together producers, researchers, retailers and others to co-create a resilient regenerative agriculture system in Alberta. His story highlights both the potential and humility required to farm with nature, not against it.