A University of Arkansas plant pathologist, John Rupe, today reported the presence of spores like those associated with Asian soybean rust in St. Joseph, La., where they were captured by a Syntinel spore trap.
Monitored by Louisiana State extension specialists, the spore trap in Tensas County, located near the Louisiana border between Natchez, Miss. and Vicksburg, Miss., tested positive for the presence of three spores associated with soybean rust. "With the limited number of spores captured, it isn't time to panic, just a warning to be extra mindful of what is going on in your soybean field," says Marty Wiglesworth, technical manager for Syngenta Crop Protection.
Utilizing technology developed for rust detection in Brazil and Paraguay, Syntinel spore traps are custom-designed traps monitored by trained pathologists to detect rust spores in the area. Spore traps are able to detect spores in the air and collect samples for lab analysis. The Syntinel trap network, exclusive to Syngenta, consists of nearly 100 traps across the country, with an early-season emphasis in the southern soybean-growing areas of the United States. By capturing windborne spores, the Syntinel traps can provide an early alert system of the potential of rust development in a specific area.
"It is important to keep in mind that soybean rust infections have not yet been found on soybean plants in Louisiana," says Wiglesworth. "However, the discovery of these spores is indicative of a possible spore shower and could be an early-warning of the disease if weather conditions are conducive for disease development and the soybean plants are at a susceptible growth stage."
Research indicates that soybean plants are most susceptible to soybean rust during the reproductive stages from R1 to R6. "Protection during pod set and fill is essential to protect yield," says Wiglesworth. "A combination of a strobilurin and triazole, such as Quit fungicide, helps protect the plant during these critical stages."
Extension agents in the surrounding areas have been notified of the discovery. "If you are a soybean grower in the area and unsure of what to do next, it would be best for you to discuss your options with your extension agent," says Wiglesworth. Growers can also monitor weather conditions and wind patterns in their area, and further spore trap developments on