Collective soybean crops across Mississippi are rated above average, according to an Extension specialist, while the immediate threat of Asian soybean rust appears to be diminished and possibly delayed until at least another season.
Speaking at the Terral Seed Corn, Soybean and Grain Sorghum Research Field Day on July 14 near Greenville, Miss., Alan Blaine, soybean specialist with Mississippi State University, said most soybeans have reached R4 stage, while some other crops have already matured.
“We feel that if rust comes into the Mid-South today, it is going to be found only in various pockets. It may be here in one place, then another field 30 miles up the road before you find anymore,” Blaine said.
Recently, the first evidence of the rust disease in commercial plots was confirmed in Alabama, just north of the Gulf Shore area.
The discovery was made about two weeks after the disease was identified in sentinel plots in the same region.
“(Hurricane) Dennis might have brought some rust, but we have not put our eyes on it (in Mississippi), so we are either going to pick up some this week or next week — if it's out there,” he said.
Blaine said for a large portion of soybeans, growth has been completed, and after another two weeks a significant portion of the remaining crop will be ready for harvest.
He expressed hope that any plots confirmed to have the disease in Alabama are continually sprayed with fungicide for the benefit of Mississippi soybean farmers, yet to find the disease on their acreage.
“If there's not rust in a lot of fields, that might help knock down inoculum potential if there is any movement this way,” he said.
Blaine cautioned growers to keep scouting for the disease because even in late-maturing periods, rust can still attack soybeans — though not as effectively as in early growth stages.
“We are over the hump, but it can still have a little effect,” he said. “What you have to decide at that time (if you find it) is how much rust you have and what the weather conditions are like. If it is hot and dry, rust is not going to hurt you.”
Blaine said that when and if Asian soybean rust strikes, based on precedent, it should not be significant on crops its first full season.
“Looking at the last 102 years, since it was first found in Japan, it has had minimal impact in a country the first year, and we are not going to be any different,” he said. “We need to keep our eyes on this through the fall and the winter. It will be very variable in the future, whether we will have to deal with it every year or not.
“But you, here in the South, are going to be on the front lines.”
Blaine said in his opinion, it is an “above average” crop of Mississippi soybeans, one that held up better than he would have predicted, given weather-related impediments.
“It's been a long season and a struggle — we were cool and dry early on,” he said.
He estimated that nearly 70 percent of soybeans are of the Group 4 varieties.
“With the kind of season we have gone through and the condition the crop is in today, if there are still some naysayers out there regarding early planting, I don't know what it is going to take to convince them.”
While Mississippi soybean growers may have circumvented rust disease in the current season, they weren't immune to other pest problems, such as spider mite.
Blaine said potato leafhoppers also emerged: “We've seen them more widespread this year than we've ever seen them. It's really negligible, not a big problem, but because of the dry weather we saw them over the entire sate.”
Blaine said scientists are running comparison tests on plots where the disease has been sprayed versus plots not sprayed.
“I think we will get a good handle on yield losses if they cause any,” he said.