In a new study measuring various factors affecting corn yield, AgCenter researchers are working to evaluate the effects of tillage, plant populations and fertilizer use along with insecticide rates and fungicide applications.

The research involves deep tillage versus no deep tillage; plant populations of 40,000 versus 32,000 plants per acre; starter fertilizer versus no starter fertilizer; foliar fungicide versus no foliar fungicide; and insecticide rates of Poncho 1250 versus Poncho 250. In addition, a higher rate of fertilizer will be used to compare with the AgCenter recommended rates.

Each treatment will be evaluated by itself and then in various combinations. AgCenter corn specialist Dan Fromme is working with AgCenter plant pathologist Trey Price and AgCenter agronomist Josh Copes on the study.

“We want to know what practices are worth the most in returns,” Fromme said.

The lowest input rates are AgCenter recommendations, which will then be compared with higher plant populations and fertilizer rates.

“We’ll do economic evaluations at the end of the year,” Fromme said.

Fromme’s plots are on the AgCenter Dean Lee Research Station station near Alexandria, while Copes and Price will have plots at the AgCenter Northeast Research Station in St. Joseph.

Fromme also is managing the on-farm demonstration program that produces the annual hybrid recommendation guide. This year the evaluations are at 18 locations, each with 13 to 14 hybrids. Conducted on individual farms, the producers follow their regular production practices, with the final result compiled in the annual hybrid report.

“Hybrid selection is one of the most important management decisions a farmer can make,” Fromme said. “And the results are surprising sometimes. Every year is different.”

Fromme also is working with Justin Dufour, an AgCenter agent in Avoyelles Parish, on a project evaluating variability in plant spacing and planting depth.

“Uniform stand is important, so we’re looking at planting at different depths and different times to get variability,” Fromme said.

In soybeans, AgCenter soybean specialist Todd Spivey is evaluating different seeding rates to determine an optimum rate.

One grower with 7,000 acres is planting 155,000 seeds per acre, Spivey said. Cutting back from 150,000 seeds per acre to 130,000 seeds per acre, for example, could save around $8.50 per acre in seed costs in a conservative estimate.

AgCenter recommendations range from 110,000 to 140,000 seeds per acre but are generally in the 120,000 to 125,000 seeds per acre range.

“The high rate is only necessary when planting early or late to assure a good stand, sort of like insurance,” Spivey said.

Keeping in mind the AgCenter generally recommends 120,000 to 125,000 seeds per acre, Spivey is planting trials using 50,000 to 175,000 seeds per acre in 25,000-seed increments.

“We want to start at a level that’s too low and go to a sufficiently high level where yields will plateau,” he said.

Last year, the test was planted at the Dean Lee station. This year, Spivey added trials at the AgCenter Sugar Research Station in St. Gabriel and the Macon

Ridge Research Station in Winnsboro as well as farmer fields in West Carroll, Pointe Coupee and Avoyelles parishes. Plots at the stations comprise four 30- to 40-foot rows, while plots on cooperator fields are 12 or 16 rows 200 to 250 yards long.

One of Spivey’s objectives is to evaluate the planting rates in different environments.

“We should have some really good data this year,” he said.

Spivey also is conducting a fertilizer study focusing on potassium by applying the nutrient at rates higher than current recommendations.

“Can we? Do we need to? Is it economical?” Spivey said are the questions the study is expected to answer.

He’s looking at timing with fall, spring and split applications with rates of 0, 30, 60, 90 and 120 pounds per acre and then comparing yields in both timing and application rates along with soil test results.

“They’re always interrelated,” he said.

The tests are being conducted at Dean Lee as well as the Northeast Research Station in St. Joseph.

“We have two different soil types at Dean Lee and one other at St. Joseph,” he said.

Another fertility study is evaluating supplemental nitrogen use at three rates along with a no-nitrogen control.

“We want to know how supplemental nitrogen application affects biological nitrogen present in the soil and if we can increase yield without spending too much money,” Spivey said.

“I’m excited for the work we do here through these grants,” Spivey said. “I think growers will get good information for the money being spent.”

Rick Bogren