What is in this article?:
- Frogeye leafspot fungus resistance to strobilurin chemistry a concern for Mid-South soybean growers
- Southern corn rust widespread in 2010
- Aerial web blight found in several areas
Add another to the growing list of weeds, insects, and diseases that have developed resistance to the chemicals that farmers rely on to control pests and protect yields — strobilurin-resistant Cercospora sojina, the fungus that causes frogeye leafspot in soybeans.
Aerial web blight found in several areas
Although some say 2010 was not necessarily a bad disease year for soybeans, there were some problem areas, Allen says.
“Aerial web blight was more a problem than in the past in the northeast and eastern areas of Mississippi. We didn’t see much in the Delta, but I think every northeast Mississippi field I was in had some aerial web blight. More typically, though, it has been a problem in soybean-rice rotations.
“It’s not easy to identify. You’ve got to get out and dig into the canopy to find it, usually in the lower portions, although it can be found higher up, depending on the time of the day. It’s one of those diseases that, if you don’t do something about it when you find it, it can take everything — leaves, pods, flowers, everything.”
Aerial web blight usually occurs in places where plants don’t get good air flow, Allen notes. As it progresses, plants will have reddish-brown leaves that are stuck together and matted. It can occur on petioles, pods, almost anywhere on the plant.
“Response to fungicides can vary widely from one field to another,” he says. “Just about every product gave an economic return when applied around R5 in trials conducted in east Mississippi.”
Managing soybean seed quality can be “a ridiculously complex challenge,” he says and can include early management decisions, environmental factors, pest management, and late management decisions.
“In 2010, we continued a massive seed quality study throughout Mississippi, with several different treatments, timings, and management practices. In almost all of the locations, the best returns were obtained when fungicide applications were made at R3.”
The Soybean Rust Hotline, which has been available to concerned members of the agriculture community since 2006, will be offered again in 2011, Allen notes.
“It’s a free service, sponsored by the Mississippi Soybean Promotion Board and BASF and it will have the latest information on the disease throughout the season.”
The toll-free telephone number for the Soybean Rust Hotline is 866-641-1847.