Jonathan Richards, LSU AgCenter plant pathologist, is studying narrow brown leaf spot disease, which is also called Cercospora leaf spot, and the different ways that farmers could control it.
Richards said the disease has the potential to decrease yields by 10% to 40%. A bad outbreak occurred in 2006 throughout Louisiana.
“It has been increasing in incidence in recent years,” Richards said.
Richards said the disease is more prevalent late in the season.
“It’s usually in the ratoon crop where it can become a really big problem,” he said.
Richards said he is looking to determine which rice varieties have resistance. He also is working to identify the different races of the pathogen in Louisiana.
In addition, he is studying control of the disease with fungicides. He said some isolates collected in Louisiana have developed resistance to strobilurin fungicides. He also is working to determine if resistance to propiconazole has developed.
Richards said he is working with AgCenter rice breeder Adam Famoso to identify genetic markers linked to resistance to narrow brown leaf spot.
He said he has collected over 300 isolates of the fungus that causes narrow brown leaf spot, and next year that effort will include sampling in north Louisiana. Richards said he also plans to study the disease in row rice.
The LSU AgCenter and the LSU College of Agriculture