Pest Alert: Soybean Rust Update
Date: October 10, 2013
From: Jim Dunphy, Extension Soybean Specialist, and Steve Koenning, Extension Plant Pathologist
Soybean rust was identified on a soybean sample submitted by Mac Malloy on a sample sent from Robeson County, 39 of 39 leaves had pustules. Additionally, sentinel plots from Wayne County (2 leaves out of 34) and Johnston County (9 out of 25) were sampled. Bennett Wilder of Columbus County submitted a sample October 9 that was confirmed to have rust (23 of 44 leaves examined). In an e-mail from Steve Gibson, rust was found on October 9 in Catawba County and he reports that most fields in that part of the state have some rust. Thus far, we have found rust in 10 of this state’s counties and assume that rust can be found in most any field that still has leaves. Combined with the confirmed finds in Virginia, essentially all the state’s soybeans are within 100 miles of known rust.
We would consider that rust spores are probably in any soybean field in the state. Rust will likely progress rapidly in fields that still have soybean leaves but most soybean is at a stage where fungicide applications are prohibited. Late planted soybeans are still at risk though it seems likely that much of the states’ soybean crop will not be affected adversely by rust this year.
Some sources for more detailed information on Asiatic soybean rust are listed below:
USDA soybean rust web site: http://www.sbrusa.net/
North Carolina Agricultural Chemical Manual: https://content.ces.ncsu.edu/north-carolina-agricultural-chemicals-manual