Caldwell County Agline

Soybean rust is viable in parts of Florida and Texas at this time. Rust was found fairly far north in Mississippi on kudzu, but was under water for sometime and though the kudzu may recover from flooding, the rust will have to reach this site again to initiate new infections. Rust may be active in Mexico onvolunteer soybean growing in corn on a limited acreage, but there is a good chance that these volunteer soybean have since been killed with herbicides.Though we have yet to receive reports of soybean rust on jicama (yambean, a crop grown in Mexico on as much as 100,000 acres) there is a good possibility that it may be developing there since yam bean has been planted andthe rainy season has or should start soon. Planting of sentinel plots in Florida, Louisiana, and Mississippi has been completed, though some sites mayhave to be replanted because of excessive rainfall. Some early maturing soybeanin Mississippi and Louisiana are now flowering and conditions are good for rust development, but planting delays may inhibit development of rust in these locations.

Another Host for Soybean Rust

A new host for soybean rust in the US is Coral Bean, grown in many areas especially along the East coast. Pictures of this plant can be found at  http://www.floridata.com/ref/E/erythrin.cfm.Coral bean is most likely to serve as an additional over wintering host for soybean rust in the gulf coast states, and its contributions to the epidemiology of have not been assessed at this time.

Soybean Rust Summary for North Carolina - Reflections on 2005-2007

Soybean rust has been detected in North Carolina every year since 2005. Rust was found in 17, 44, and 6 counties in 2005, 2006, and 2007 respectively. For the most part it has not required fungicide sprays. Only in 2006 was it recommended that fungicides be sprayed in the southeastern counties on late planted late maturity soybean. Yield increases in these areas were on the order of 4 to 5 bushels per acre.

Resources for Soybean Rust in 2008

Soybean rust sentinel plots will be planted inthe next 30 days in most locations. In addition, we have a teletip phone number 1-800-662-7301 (the same number as for the cottoninsect update) with a message updated as necessary.

There are more resources for information on Asiatic soybean rust available this year than in many years in the past. Soybean Rust Management in the Mid-AtlanticRegion can be found at the SSDW web site http://cipm.ncsu.edu/ent/SSDW/, as well as the Soybean Disease Atlas. The Fungicide Manual is available as a PDF version from http://oardc.osu.edu/soyrust/. This Fungicide Manual actually contains more information than most growers are likely to need.

Some sources for more detailed information are listedbelow:

• The USDA soybean rust web site http://www.sbrusa.net/cgi-bin/sbr/public.cgi
• The North Carolina Crop Protection Manual http://ipm.ncsu.edu/agchem/6-9.pdf
• Fungicide Manual http://oardc.osu.edu/soyrust/