BATON ROUGE, La. (AP) — Asian soybean rust is showing up earlier and in more places than usual, The LSU AgCenter says.
It has shown up in eight parishes, mainly along the coast, and in 6-inch-high "volunteer" soybean seedlings, indicating that the fungus can survive through a mild winter in Louisiana, plant pathologist Clayton Hollier said.
It is known to attack more than 100 plants, with soybeans and kudzu the most susceptible.
It was found Jan. 2 in kudzu on Perkins Road in Baton Rouge.
Soybean growers are advised to keep an eye out, because they may have to use fungicides earlier than usual.
"The reason we haven't had an epidemic here is because it takes time to build up after a freeze has killed it back," Hollier said. "By the time it builds back up, we're actually late in the growing season."
Asian soybean rust was first found Louisiana in 2004, probably brought in early that fall by Hurricane Ivan.
"We looked at the track of Ivan, and we believe it picked the spores in Columbia," Hollier said. "Everywhere the storm went once it hit land was seen to have the disease."
In the past, freezing temperatures have kept it from growing until the soybean crop was developed enough to withstand it.
"The chance of the disease affecting soybeans early this year can all be changed by a few nights or days with temperatures in the lower 20s," he said.
Even if the disease gets an early start this year, growers have several chemicals that are very effective, he said.
The first discovery of the disease in North America was by LSU AgCenter scientist Ray Schneider, who found it in a field on the Ben Hur Research Farm near the LSU campus.
It was first identified in 1902, in Japan and was largely confined to Asia until the late 1990s, when it spread to Africa and in 2001 was found in South America.
"In some of these countries, the disease actually caused 100 percent crop failure," Hollier said.