Soybean Rust Update
By Laura Sweets

The soybean rust sentinel plot system is up and running for the 2006 season (www.sbrusa.net). Missouri is again cooperating in this effort. Right now it looks as though there should be 26 sentinel plots located throughout the soybean producing areas of the state. Some sentinel plots have plants in the early vegetative stages and have been scouted for soybean rust. The procedure this season is for 100 terminal leaflets from the lower canopy to be submitted for microscopic examination for soybean rust. Foliage samples submitted from Pemiscot County and Scott County were negative for soybean rust.

Scouting has been intensive in the southern states, first on kudzu and now on kudzu and soybeans, especially soybeans planted in sentinel plots. Rust has been confirmed in five counties in Alabama, eleven counties in Florida, four counties in Georgia and one county in Texas. Most of these finds have been on kudzu. There are no current reports of soybean rust on newly planted soybean in 2006 including volunteer soybean plants. Several of the southern states are reporting hot, dry weather that is not conducive to the development of soybean rust. In their latest reports both Louisiana and Florida mentioned that periodic rains, extended dews and high humidity are maintaining moisture in the canopy which could be more favorable for the development of foliage diseases including soybean rust. Sentinel plots are being scouted on a weekly basis.

Although soybean rust appears to be slow in developing or moving in the south, it is still early in the season. It is very important to keep up-to-date on the occurrence of the disease and changes in weather patterns in the southern states.

Laura Sweets
573-884-7307