With rainfall becoming more frequent, rice farmers should be alert for diseases on their crops, according to an LSU AgCenter expert who spoke at the Acadia Parish Rice Tour Wednesday.

Leaf blast and sheath blight are starting to show up in fields, said LSU AgCenter plant pathologist Don Groth. Sheath blight can reduce yields by 10-20 percent, he said, but the effects of blast are far worse.

“Blast can take the whole crop,” Groth said.

Groth said applying a fungicide at the proper time is necessary. The best time for a fungicide application to fight blast is very early in the heading stage when about 50 percent of the tillers are showing some part of the emerging panicle, he said.

“When the head emerges is when it’s susceptible to blast,” Groth said. Once the head is fully emerged, he said, it’s too late for fungicide.

Soybean farmers should be on the lookout for aerial blight and frogeye cercospera, he added.

Groth also said Asian soybean rust is not expected to be as great of a threat in Louisiana this year because the cold weather killed kudzu and volunteer soybeans in which the fungus overwinters.