AgFax Southern Grain: Louisiana

by AgFax Media LLC, AgFax.com

OVERVIEW

Soybean loopers remain the key pest in beans through much of the South, although some mix of worms can be found in many fields. Bollworms remain a potential issue in late soybeans. In Virginia, the latest round of vial testing showed a high level of survivability/resistance. 

Stink bug treatments are being made, but the insect appears to be surprisingly light this season in parts of the region. The exception, of course, is the redbanded stink bug, which expanded its range in the Delta states this summer, thanks to mild winter weather. Enough treatments have been necessary that ag dealers ran short on one key insecticide. Other bugs – notably kudzu bugs and bean leaf beetles – have required applications, mostly on a localized basis.

Soybean harvest has cranked up on a somewhat wider scale in the Midsouth. Corn harvest has wrapped up in portions of the lower South.

Soybean rust has been confirmed in Coffee County in Middle Tennessee. That is the farthest north it has been found so far this season, based on USDA's tracking map.

LOUISIANA CROP REPORTS

David Kerns, Entomologist, Louisiana State University, Macon Ridge Research Station:

"I'm hearing about some good soybean yields in portions of north Louisiana where harvest has started. But in some other parts of the state where it rained more and flooding occurred, much of the bean crop ranges from very rough to devastated.

"In later beans we've got some mix of loopers, green cloverworms and velvetbean caterpillars. Where I've been, the mix is mostly loopers with 25% to 30% green cloverworms. We're seeing some significant defoliation, and control has been sporadic. It's been raining every afternoon in many areas, so treatments can't always go on when needed. People are reporting poor performance with certain products. Some worms typically get through, of course, although we don't always know why. But the main issue has been wash-off, I suspect.

"Redbanded stink bugs have been relentless in soybeans. With all this rain, we've been unable to stay on top of them, and wash-off and treatment delays have certainly been factors. Typically, we would be shortening the spray intervals to break the cycles, but that's mostly been impossible due to the frequent showers. Added to that, dealers are running low on acephate, our main chemistry for redbanded.

"The standard for redbanded has been acephate and a high rate of bifenthrin. But if fields have high adult populations, plus immatures and eggs, that's when you can run into problems. What I like to recommend – but it's expensive – is a 4-ounce/acre rate of Belay mixed with bifenthrin. Belay is a neonic that for whatever reason has always had more activity on stink bugs than related chemistry.

"Our toolbox for redbanded isn't as big as we would like. Acephate's label also limits total seasonal applications to 2.5 lbs/acre, so some growers have topped out on the amount they can use this year. Part of usage is due to wash-off situations where it rained and farmers had to respray."

Travis Vallee, CenLa Ag Services, Pineville, Louisiana:

"A couple of farmers have been able to cut a few acres of soybeans. With one grower, the weather-related damage ran 5% to 8%. The other grower started in some fields with 20% to 50% damage, mostly rotting, and I think some of this will get worse before it gets better.

"It's been interesting that 80% of the beans that sprouted had cercospora on the pods before they sprouted. We still have hope for the later beans, but some of those took a hit from stink bugs when we couldn't spray. Ag pilots had been running as much as a week behind with all the weather delays.

"The few beans that are holding up well were treated twice with fungicides – at R3 and R5.5. Irrigated beans that still had decent quality were cutting 80 bu/acre. Seed quality also seems to be better in other fields that had later fungicide treatments. It was hot and dry during much of the season on the early beans, so fungicides either weren't applied at all or went out late after a couple of good rains.

"We're wrapping up corn harvest. Yield-wise, corn has done fairly well. Where we replanted with some unfamiliar hybrids the yields were off 25 to 40 bu/acre. Where we replanted with our preferred hybrids, no yield difference seemed apparent. Even in some marginal populations, we did well."