A team of researchers, including NDSU AES Plant Pathology Associate Professor Febina Mathew and NDSU AES Plant Pathology Professor Samuel Markell, has achieved a breakthrough in combating Phomopsis stem canker. This devastating disease severely threatens sunflower crops in the U.S. Northern Great Plains region in 2010.

Phomopsis stem canker has become a significant concern for sunflower farmers as it impairs crop yield and oil quality. The research team conducted an extensive analysis of 56 foliar fungicide efficacy trials from 2009 to 2021 across Minnesota, Nebraska, North Dakota, and South Dakota.  The study specifically concentrated on the Northern Great Plains region, taking into account the substantial number of sunflower fields in this area. Notably, North Dakota and South Dakota are responsible for the majority of sunflower production in the United States.

Sunflowers are an important agriculture commodity to the nation with interest increasing annually. According to the USDA and the National Sunflower Association, the United States sunflower production in 2022 totaled 2.81 billion pounds, which was an increase of 48% from 2021. North Dakota was the top producing state in 2022, harvesting a total of 1.34 billion pounds of sunflower (up 76% from 2021). South Dakota harvested 1.08 billion pounds, and Minnesota's production totaled 174.7 million pounds (which was 86% higher than 2021).

The study's main objective was to compare the effectiveness of different foliar fungicide application timings and active ingredients in combating Phomopsis stem canker.

“We developed a meta-analysis to compare the fungicide treatments with a nontreated control (NTC) and determine their impact on the disease severity index (DSI) and yield”.

The results show that a single application of fungicide products containing pyraclostrobin at miniature floral bud initiation growth stage is effective against Diaporthe species causing Phomopsis stem canker. They also determined that the probability of recovering the fungicide application costs was greater than 0.65, which suggested farmers will get a greater return on investment.

Their research was recently published in Plant Health Progress, a publication that specializes in various aspects of plant health, including diseases, pests, and crop management strategies. Since being published, their research has garnered significant recognition as an Editor's Pick in the issue due to the potential impact of their findings on sunflower farming.

The recognition of this research as an Editor's Pick highlights the significance and impact of the findings and showcases the contributions made by the research team, including Drs. Ruchika Kashyap, Robert M. Harveson, and Hossein M. Rekabdarkolaee, in addition to Markell and Mathew.