Their origin is still unknown, but spores found in a spore trap near Houston, Texas are thought to be Asian soybean rust. According to a Dow Jones Newswire story, the spores were discovered May 11 in a trap operated by Syngenta.

The spores do not prove rust has actually developed in a given area, however similar discoveries in other areas preceded rust infections the first year that the traps were deployed.

Experts say that rust from a Texas source is more likely to spread to Midwest soybean producing areas than a rust infection source in the southeastern United States.

Meanwhile, a DTN story says 650 acres of seed soybeans are affected by Asian soybean rust near Tampico, Mexico, about 200 miles south of Texas. Those soybeans were harvested and the plants destroyed.

Experts are less worried about spread from that infection because of the planting gap between that part of Mexico and the United States.