We’ve all heard rumblings of extremely early Asian soybean rust (ASR) confirmations in the South and many are wondering if this may be the year tropical storms spread the disease into the Midwest. The truth is no one can know with certainty, but early presence of ASR, a few tropical storms and the right temperatures could pave the way for an outbreak in 2016.
The NAOO’s 2016 Atlantic Hurricane Season Outlook predicts a total of 10 to 16 named storms, 4 to 8 hurricanes, and 1 to 4 major hurricanes this year. Although this report is within the “normal average,” early reports of rust in the South makes it more likely that each of these storms could be successful in spreading rust to the Midwest.
As the PIPE ASR tracker from June 28 shows, the disease is currently confined to Florida, Georgia, Mississippi, Alabama and Louisiana. Fortunately, confirmation of the disease in soybeans has been limited and while it’s been humid, temps have begun to climb above the ideal threshold for the disease (70 to 80 degrees Fahrenheit) so it may be a non-issue for 2016.
Yet, I still encourage growers to monitor the situation by keeping an eye on the rust tracker and staying in touch with their local extension agent. In the event of a hurricane or tropical storm, growers should monitor crops for gray, tan or reddish brown small, growing pustules or lesions on the leaves and stem pods. Once present, symptoms of rust in soybeans can become apparent in as little as nine days. Regular scouting for rust this season, especially during R1-R2, can be critical to prevent significant yield losses.
In the event ASR does make it into the Midwest, I recommend growers make a preventive fungicide treatment to stop the disease before it gets hold of the crop and yields take a hit. Growers looking for longer residual disease control in soybeans, corn and wheat should take a look at Trivapro fungicide. Available for the first time this season, Trivapro was designed with rust in mind, has three modes of action and offers preventive and curative disease control.
With more than 19 years of experience, Eric currently manages the development and deployment of new fungicide technologies for Syngenta. Holding his Ph.D. in plant pathology, Eric’s background consists of substantial experience with fungicide technical development, postharvest disease control, biological control, and nematology.