By STAN MADDUX

Indiana Correspondent

URBANA, Ill. — There’s been a possible breakthrough in curtailing fungus that can quickly devastate a corn crop.

Researchers in the Department of Crop Sciences at the University of Illinois have figured out how the northern corn leaf blight gets around the defense mechanisms in corn. Now, the objective is developing ways to stop the fungus from outsmarting the defenses contained in the genes of the plant.

“With this information, corn breeders could someday build more durable resistance in future hybrids,” said Santiago Mideros, a plant pathologist at the university.

The research published in the journal Phytopathology uncovered two of the genes that cause disease in corn and mated them with strains of the fungus that cause and don’t cause disease. Mapping of the genes allowed researchers to detect of which gene allows the fungus to cause disease in the plant, Mideros said.

Also identified from the research were molecular markers that should make identifying disease-causing strains easier in the future.

“Now that we have molecular markers, we could sample the environment and find out which strains of the pathogen are out there. Eventually, farmers might be able to plant corn varieties that are resistant to specific pathogens present in their area,” he explained.

He emphasized there’s still a long way to go to reach that point, but the recent findings are a first step.

According to researchers at Purdue University, northern corn leaf blight, which is recognizable by tan-colored, cigar-shaped lesions, has become more prevalent in the Midwest since the mid- to late 2000s. Yield loss can result if blight develops before or during the tasseling and silking phases of corn growth.

The fungus survives the winter in corn residue on the soil’s surface. Spores develop in the residue during the early spring and summer, then get blown onto the leaves of the new crop. The health of the corn plant is negatively impacted by lesions blocking the ability of the leaves from carrying out photosynthesis.

Hybrid yields can be reduced by as much as 30 percent if blight is not detected early. Infection is more likely during periods of moderately warm temperatures along with wet and humid conditions.

Yield losses can be more dramatic in sweet corn, popcorn and other specialty corn plants, according to the Purdue researchers. According to the Crop Protection Network, the United States and Ontario produced 15.5 billion bushels of corn in 2016 and northern corn leaf blight was blamed for 151 million bushels lost.

Only gray leaf spot and southern rust are ahead in terms of lost yields among the leaf diseases.