More than 170 farmers and agriculture industry representatives heard about the latest research on corn, soybeans and cotton at the annual field day held June 14 at the LSU AgCenter Northeast Research Station.

LibertyLink technology is proving effective for controlling weeds in all three crops, said LSU AgCenter weed scientist Donnie Miller. “There are not many broadleaf weeds it will not work on,” he said of Liberty herbicide.

Liberty is “fantastic” on broadleaf weeds, but producers need to apply it on Palmer amaranth when the weed plants are less than 2-3 inches, Miller said.

The weed scientist has put out his research plots in a “systems approach” with different chemicals used alone or in combination at different rates with Liberty. “Liberty needs help with grasses. If you make timely applications without using a residual herbicide, you’ll get good control. But if you are delayed, grass and pigweed control can benefit from residual materials.” 

Weed resistance to Liberty is still “rearing its head,” and farmers should use additional herbicides when necessary to control potentially resistant weeds that escape initial herbicide applications.

In other soybean research, Theo Udeigwe introduced the audience to a new study looking at various soybean varieties and maturity groups in different “planting windows” that go from early April to early June.

The evaluation at the Northeast Research Station is one of eight locations across the Mid-South, Udeigwe said.

In the trials, Udeigwe planted four soybean varieties from each of four maturity groups -- III, IV, V and VI. The goal of the study is to determine which varieties do better when planted earlier.

“Early planting optimizes growth because cooler temperatures help early growth,” said LSU AgCenter soybean specialist Ronnie Levy. “Every variety is a little different.”

Soybean problems this year include western flower thrips, which are more difficult than other insects to control, said LSU AgCenter agent Sebe Brown.

Brown has heard rumors of tarnished plant bugs and warned producers to be aware of flea hoppers. He also heard one report of corn earworm in soybeans.

Producers should begin scouting for red banded stink bugs. “They can move in quickly,” Brown said. “Scout regularly and scout often.”

LSU AgCenter entomologist David Kerns said he’s compared in-furrow treatments with seed treatments for thrips control. “In general, in-furrow treatments tend to control thrips better than seed treatments.”

He pointed to how different chemicals can be used to control thrips.

Planting date is critical for top corn yields and profit, said LSU AgCenter agronomist Rick Mascagni, who is evaluating how different hybrids respond to different planting dates. “We want to try to find hybrids that can perform well with later planting.” 

The optimum corn planting date in north Louisiana generally is in March and extends into early April. “Extending the planting date into May can result in a yield reduction of 30 percent or more,” Mascagni said.

LSU AgCenter county agents Dennis Burns and R.L. Frazier described their work with precision agriculture and how they’re moving practices from the research stations to farms by working with producers in their own operations.

The agents are introducing a practice called NDVI -- normalized difference vegetation -- that uses equipment on a fertilizer applicator to “read” the amount of vegetation at a particular spot in the field and adjust fertilizer application rates “on the fly” to apply the appropriate amount of nitrogen. 

The equipment can be used for both pesticide and fertilizer application. The agents set out plots with nitrogen fertilizer rates ranging from zero to 250 pounds per acre to see how much they can reduce fertilizer application without reducing yield.

LSU AgCenter corn specialist John Kruse said a USDA competitive grant is funding his research on feedstocks for biofuels, including energy cane and sweet sorghum. The objective of the five-year study is to see how far north these traditionally warm-weather crops can produce well. The study will test for genetic potential and performance at different plant populations.

The study will measure “how many plants can we pack into an acre to take advantage of the nutrients and photosynthesis,” Kruse said.

LSU AgCenter Master Farmer coordinator Donna Morgan and watershed agent James Hendrix provided updates on the Louisiana Master Farmer program.

They said phase III of the program has changed with the opportunity to develop a conservation plan through the local Soil and Water Conservation District.

LSU AgCenter soil scientist J Stevens explained his work with soil pH and problems with a shallow hardpan layer below the soil surface. He showed cotton plants with roots that run parallel to the soil surface because they can’t penetrate the hardpan layer.

LSU AgCenter agronomist Josh Lofton said using the nutrients in poultry litter can improve cotton yields, and benefits increase when the product is used in a no-till operation.

A combination of poultry litter and inorganic fertilizer can help manage phosphorus runoff from production fields, he said.

Several LSU AgCenter experts provided insight on current crop conditions:

  • Kruse estimated this year’s corn crop in Louisiana at 600,000 acres, up from 500,000 in 2011.

“In general, the corn crop went in a little bit earlier than normal,” Kruse said. This year’s crop should fare better than average, and harvest should start in July.

  • Levy said the state probably has more than 1 million acres in soybeans, but he said that will increase because some farmers are still planting. Last year’s total was slightly less than 1 million.

“We probably have one of the best crops I’ve seen but weather conditions could change that in a hurry,” Levy said.

  • LSU AgCenter weed scientist Eric Webster warned that new herbicides about to be released can be susceptible to drift, despite manufacturers’ claims. Any sprayed material can be carried aloft in the air if sprayed at the wrong time.

One of the worst conditions for drift is little to no wind with high humidity -- conditions that will create an inversion and carry droplets a distance from the intended field. Some of the worst drift cases Webster has seen occurred from ground spray rigs.

  • LSU AgCenter plant pathologist Boyd Padgett said corn diseases appear to be low and encouraged producers to identify any diseases before applying a fungicide.

Because of reports of cercospora on soybeans, Padgett recommended early-season fungicide applications at first bloom. “If you’re following that strategy, you’ll have to consider reapplying.”

  • Farmers should consider post-harvest control of pigweed in corn fields, said LSU AgCenter weed scientist Daniel Stephenson.

“We have tools we can use on weed emergence in corn post-harvest,” Stephenson said, reviewing several herbicides that can be effective.