August 14, 2008

There were concerns that tropical storm Edouard may bring soy rust into the Midwest, which could obliterate the soy crop, but experts are now allaying those fears by saying that the soy crop is relatively safe.

Midwest agronomists say there is likely no reason for worries. However, field scouts in further south are keeping an eye out for the soy crop as rust may sneak up on late-planted soy while they are susceptible to damage.

Allen Wrather, plant pathologist at the University of Missouri, said last year's soy rust invaded in mid-September, which was unusual as in the past it has only developed in mid to late-October.

"Our worry is that the same will happen this year, and because of late planting, rust developing in mid-September could really damage yield," Wrather said.

However, Iowa State University (ISU) plant pathologist Daren Mueller said weather conditions in rust-prone regions have taken a turn for the better in terms of rust propagation.

Mueller said drier than normal conditions continue to plague southeast US, which has slowed the movement of soy rust.

This means that even the latest-planted soy is unlikely to be infected this year. Midwestern fields that planted the latest would have reached the R6 growth stage by mid-September, which would be too late for soy rust to cause economic damage, according to data collected by ISU plant pathologist Palle Pedersen.

Purdue University soy rust specialist Kiersten Wise said even if they were to find soy rust this week, it would not at a level that requires immediate treatment.

Wise added that their initial soy rust spores are extremely low when compared to Brazil, and that gives them ample time to apply fungicides if it is required.