The year 2009 was a very good one for Alabama soybean producers, with a record yield of 40 bushels per acre from approximately 430,000 acres, says Dennis Delaney, Auburn University Extension soybean specialist.
Soybean  acreage has been climbing steadily in the state since 2005, when 145,000 acres were planted.
But this past year wasn’t without its challenges, said Delaney, speaking at the recent East Central Alabama Cotton and Soybean Workshop held in Shorter, Ala. Planting was delayed by wet conditions and then it turned dry after wheat harvest. “We had a relatively wet and cool summer. We had some very good yields from Maturity Group (MG) IV beans and then we had some rain damage,” he says.
But the late-season beans made up the difference, he adds, with plenty of rainfall and yields that kept climbing. “A late harvest was messy, but it didn’t hurt the late beans as much, and cooler temperatures made for less seed damage,” says Delaney.
Looking ahead to this year, due to a wet harvest in Arkansas and Mississippi, there was some concern over seed quality for 2010, but Delaney doesn’t believe that will prove to be a major issue. As far as varieties go, Roundup Ready 2 Yield soybeans will be available in more Group IVs, along with some more MG VI varieties.
“There are fast-changing lineups in soybean varieties from year to year, and it can be difficult to keep up,” he says. “A variety may last three years at the most, and then it is replaced by a new, hopefully better, variety.”
Delaney advises growers to use multiple sources of information when selecting varieties, being careful to choose them for the nematode and disease resistance required by a particular field situation.
“A lot of growers are now in their third and fourth years of growing soybeans, and if you remember back to the 1980s, that’s when we started seeing more problems with cyst nematodes, so be aware of this potential problem. Disease resistance is best when bought in the bag rather than attempting to spray it on,” he says.
“A lot of the strict rules of planting have gone out the window as we have gotten more early-maturing varieties. As a general rule, in Alabama, we plant Group IVs early April through early May, Group Vs May 1 through mid-June, and Groups VI, VII and VIII May 5 through mid-June. If you can’t plant at an optimum time, you can compensate by going with closer row spacing or by bumping up the plant population so you’ll have more plants if they bloom out early,” he says.
The rule for years has been to inoculate with rhizobia if land has been out of soybeans for three years or more, says Delaney. And, in some cases, there might be a slight yield boost from the inoculation even if the land hasn’t been out of beans. But in nine replicated trials conducted in the last three years, no significant yield increase has been seen, he says.
In 2008 and in 2009, there were reports of pre-inoculation failures, says Delaney, and these could have been attributed to several causes, including the improper storage of the product; chlorine in the mix water; mixing the product with the wrong fungicides or mixing for too long; the product getting too hot in the warehouse, shed, on the truck, or in the planter; and flooded conditions during the early growth stage of the soybean plant.
“In the case of failure, there’s really no good answer, except for applying the 3 pounds per acre of nitrogen per bushel of yield expected,” he says.
Turning to Asian Soybean Rust, Delaney says the disease got a slow start in 2009, found for the first time on June 11 on kudzu in Baldwin County. It was found on soybeans for the first time on Aug. 3. By Oct. 8, it had spread to all 67 Alabama counties — the first time in the United States the disease had been found in every county of a state.
The disease was easily found in many late-planted, unsprayed fields, and there was some damage to unsprayed fields, mostly in the southern region of Alabama. Growers can stay updated on the status of Asian Soybean Rust through the Web site www.sbrusa.net  or through the Alabama Soybean Rust Hotline at 1-800-446-0388.
e-mail: [email protected]