The number of counties positive for soybean rust in South Carolina doubled to 10 today with the confirmation of infections in five more counties. And in Texas, eight more commercial fields in Liberty County are positive for rust.



There are now 50 positive counties/parishes in the U.S.



The new South Carolina counties are Anderson, Colleton, Dorchester, Horry and Lee.



The South Carolina state commentary on www.sbrusa.net said today that "Rust is widespread enough in the state that anyone with soybeans in the R4 to early R5 stage should consider spraying with a fungicide. Since rust seems to be established in a wide area, the use of a triazole to help eradicate the rust that is already present is warranted. If controlling foliar and pod & stem diseases is also an objective, the triazole needs to be combined with a strobilurin."



The commentary listed the 10 counties in South Carolina with rust as Anderson, Calhoun, Colleton, Dorchester, Florence, Hampton, Horry, Lee, Orangeburg and Sumter.



"All of the finds except Dorchester County were located at Maturity Group 5 sentinel plots (Orangeburg was MG 4 & 5 sentinel plots). I would characterize all of the finds as relatively light in severity except Horry, Orangeburg and Sumter counties, which had slightly higher levels of rust," said John Mueller, Extension soybean pathologist, Clemson University, in the commentary and in today's South Carolina Soybean Rust Note e-mail newsletter.



"Counties sampled last week in which we could not find rust included: Aiken, Allendale, Bamberg, Barnwell, Clarendon, Darlington, Edgefield, Kershaw, Newberry, and Williamsburg. We will continue to monitor these counties for rust."



In addition to the fungicide recommendation mentioned earlier in the article, the commentary said:



"Many growers are combining their fungicide sprays with an insecticide for stink bugs. This appears to be a very good idea in many areas. Dr. (Michael) Sullivan reports that high levels of stink bugs are present in many of the fields he scouts. We have also heard reports of high levels of stink bugs north of the lakes.



"Pyrethroids remain the most economical and efficacious materials for control of stink bugs. They will tank-mix well with most fungicides. Be particularly careful when selecting a pyrethroid insecticide, because many of the generic pyrethroids labeled for use in cotton are not labeled for use in soybean. CHECK THE LABEL to be sure you can legally use the product you have chosen on soybean."



Texas reports eight more commercial fields with rust



In today's commentary on www.sbrusa.net, Texas officials said:



"On Sept. 8, eight additional commercial soybean fields with soybean rust were found in Liberty County. The incidence of rust was low and confined to the lower canopy of these fields. No rust has been reported anywhere else in the state.



"Commercial soybeans and sentinel plots in southern Texas are approaching maturity or have been harvested. Group 5 soybeans in Liberty County are at R8, while group 6 and7 soybeans are at R5 to R6. The limited acreage (less than 1,000 acres) of Group 6 or Group 7 soybeans in Liberty County that are at growth stage R5 or younger are at greatest risk for rust. These fields are likely to be treated in the coming week.



"Fields in other areas should be monitored frequently and sprayed with a triazole fungicide at the first indication of rust. At this time, I am not recommending preventative applications of fungicides at other locations," said Tom Isakeit, Extension plant pathologist at Texas A&M.



SOURCE: South Carolina, Texas state commentaries on www.sbrusa.net.