Soybean plants are housed in a humidity chamber in a greenhouse after inoculation to promote aerial blight infection and disease development for research purposes. Photos by Jonathan Amie

Work is still underway to identify soybean varieties resistant to aerial blight. LSU AgCenter plant pathologist Sara Thomas-Sharma’s ongoing project screens plants in a greenhouse to improve disease management.

Last year, the project team screened 21 core block soybean varieties as a part of the annual variety trials and germplasm screenings. To assess their resistance to blight, they were grown in a controlled greenhouse setting.

“We did the trial twice, and none of the varieties showed up as being resistant,” Thomas-Sharma said.

There were concerns that the results from 2024 trials were influenced by cold temperatures, given that they were done in August and January. To minimize this possibility, the 2025 trials were run in July and September.

“This year there were no concerns that the temperature differences lead to inconsistencies in the screening,” Thomas-Sharma said.

The 2025 trial results suggest that there is overall little resistance to aerial blight in commercial soybean varieties.

Aerial blight is caused by a soilborne pathogen. It is difficult to monitor in a field due to its patchy distribution which is why Thomas-Sharma opts to use a greenhouse.

While no resistant varieties were identified, the research provides valuable insights for growers in high disease pressure areas and was published in the 2026 Soybean Variety Yields and Production Practices.

“Once a field has experienced this disease, there’s a good chance it will show up again because the pathogen survives in the soil,” Thomas-Sharma said. “These results can help growers compare varieties and choose options that may offer better protection.”

Fungicide resistance in the pathogen population adds a layer of complexity to disease management.

“Resistance to commonly used fungicides is a concern with this pathogen,” Thomas-Sharma said. “In a smaller study, we detected resistance, but additional research is needed to determine how widespread the issue is across Louisiana.”

Ultimately, the goal is to support integrated disease management.

“Effective disease management depends on using multiple approaches together rather than relying on one solution,” Thomas-Sharma said. “Selecting resistant is one of the most important tools growers can include in an integrated management program.”