LSU AgCenter weed scientist Daniel Stephenson, far right, tells farmers at the St. Landry Parish wheat and feed grain production meeting on Jan. 22 about how to manage herbicide-resistant weeds. (Photo by Bruce Schultz)

News Release Distributed 01/26/15

OPELOUSAS, La. – Louisiana led the nation for the average soybean yield last year, according to the LSU AgCenter soybean specialist.

The U.S. Department of Agriculture recently released the average state yield of 57 bushels an acre, said Ron Levy, speaking at the St. Landry Parish wheat and feed grain production meeting on Jan. 22.

“Not many years ago, we were close to the bottom,” Levy said.

Behind Louisiana were Illinois and Indiana, both with an average yield of 56 bushels an acre.

The national average was 47.8 bushels per acre, which is well above the average soybean yields of 44 bushels per acre in 2013.

One reason for Louisiana’s top ranking could be attributed to bad planting conditions in southwest Louisiana last year that eliminated marginal land from growing a crop, Levy said. Louisiana farmers harvested 1.4 million acres of soybeans in 2014, and 83 million acres were harvested nationwide.

Levy said high-yielding soybeans crops were planted on sugarcane ground in Louisiana, with some resulting in yields of 100 bushels an acre.

Tests have shown that plants with medium heights yield best, he said. Planting time is critical, with groups III and IV beans planted April 15 producing the best yield, and group V fared better when planted earlier.

“Doing everything on time is the most important thing you can do with soybeans, starting with having fields ready to plant,” Levy said.

The USDA also lists Louisiana’s 2014 corn yield average as the state’s best ever at 183 bushels an acre. LSU AgCenter corn specialist Dan Fromme said he thought the average would range from 165 to 172 bushels, down slightly from 2013.

AgCenter tests have shown that irrigated corn can yield 219 bushels, compared to dryland corn at 184 bushels per acre, Fromme said. Planting in south Louisiana is best from Feb. 25 to March 20, and in north Louisiana the optimum time is March 10 through April 1.

Cooler-than-average temperatures last summer resulted in a good corn crop. “That was a blessing for late-planted corn,” he said.

AgCenter entomologist Julien Beuzelin said grain sorghum farmers should be on alert for the sugarcane aphid. The pesticide Transform has a provisional permit in Louisiana against the pests that showed up in Louisiana in 2013.

Insecticide seed treatments for soybeans provide protection against a wide range of early season insects but may not be worth the expense every year for a crop planted within the recommended time frame, Beuzelin said. Soybeans planted earlier or later than the recommendations are more likely to benefit from insecticide seed treatments.

Red-banded stinkbugs were not as much of a problem last year, he said. Acephate insecticide remains the best option for the pest, he said, but resistance is becoming more of a problem.

AgCenter weed scientist Daniel Stephenson said a limited amount of Enlist soybeans, with resistance to the herbicide 2,4-D, will be released this year.

He also said a new grain sorghum variety, Inzen, tolerant to Zest herbicide, will be available from DuPont.

A soybean crop that can be kept weed-free for 5 weeks after planting can produce its maximum yield, Stephenson said. That means using a burndown herbicide before planting and a pre-emerge herbicide followed by a residual herbicide.

Corn needs protection from weed competition early, he said. “You’ve got to protect that corn early in the season. That means a burndown 4-6 weeks before planting and a post-emerge application when corn is 8-12 inches. Atrazine is still the foundation of corn weed control.”

The problem of herbicide-resistant weeds is becoming greater, he said, and Palmer amaranth, Italian ryegrass and barnyardgrass that have resistance have been confirmed in St. Landry Parish. Farm equipment can spread Palmer amaranth.

AgCenter plant pathologist Trey Price said research continues to find the cause of the disease called black root rot in soybeans. It caused significant damage in some fields last year as pods were starting to fill. The problem seems to be more prevalent in no-till fields, he said.

Cercospora leaf blight was not a big problem last year, but the disease in some St. Landry Parish fields has developed resistance to fungicides, he said. A case of sudden death syndrome was found in a soybean field in East Carroll Parish last year.

Price said the wheat disease known as bacteria streak was bad in Louisiana last year. Fungicides aren’t effective against the disease, and variety tolerance is being developed.

AgCenter agronomist Josh Lofton said fertilizer should be applied to late-planted or slow-growing wheat, with half now and the remainder towards the end of the growing period. He said a crop with yellow leaves also should be fertilized.

Lofton said the secretions of sugarcane aphids on grain sorghum will interfere with the effectiveness of glyphosate as a ripener on the plants. Sodium chlorate is the better option for a ripener if aphids are present.

Lofton said he expects grain sorghum acres in Louisiana will decline this year “because people are having trouble with Johnsongrass and aphids.”

AgCenter ag engineer Randy Price said spray nozzles should be tested regularly for uniform droplet size and flow rate, and replaced every three years because orifices enlarge over time.

AgCenter economist Kurt Guidry said corn prices should linger around $4 a bushel. “I don’t think we’re going to see $5-$6 corn without a major weather event.”

The grain sorghum outlook is better because China has been buying more of that commodity, with prices expected in the $4-$5 range, Guidry said.

The strong U.S. dollar that makes American corn more expensive to foreign buyers is hurting corn exports, he said. But Argentina, Brazil and Ukraine are expected to have decreased corn production.

Soybeans are expected to remain in the $9-$10 price range, Guidry said. A good South American crop could bring beans down to $9 per bushel. ”If we get to $10, you should seriously consider locking into that,” he said.

China recently cancelled two soybean loads, but China resumed buying on Wednesday, he said.

Guidry said he expects wheat prices to reach $6 per bushel but not increase to $7-$8. Export demand for U.S. wheat is low because other countries have wheat to sell on the world market.

Fuel and fertilizer prices should hold steady, he said.