Test Plot Roundup

March 24, 2012 05:40 AM
Test Plot Roundup

An overview from our eastern Corn Belt plots


Corn Row Spacing

The Farm Journal Test Plots studied narrow row corn, including twin rows, for more than a dozen years in central Illinois with Farm Journal Field Agronomist Ken Ferrie. Expanding that work into the eastern Corn Belt, we launched a multiyear study to evaluate twin rows compared to 30" rows. These results fall in line with the previous work that showed a 7 bu. to 10 bu. increase for twin rows over 30" rows at the same population.

"At the same population, the twins outyielded the 30" rows by 9.5 bu. in 2010 and by 3 bu. in 2011," says Associate Field Agronomist Missy Bauer. "When population was dialed in to best match the row spacing, the twins outyielded the 30" rows by 13 bu. in 2010 and 6 bu. in 2011."

Narrowing the rows allows farmers to take advantage of the yield bump from increasing populations, Bauer explains. "We want to be cautious not to push population too far in narrow rows, especially with hybrids that have a lot of ear flex. In these cases, we may see yields go backwards. Hybrid selection and other agronomic practices have to be tuned to twin row production—it’s not just something to consider at planting."

Beyond hybrid selection, practices that require special consideration with twin rows include fertility management, insect scouting, disease management and variable-rate planting.

"Narrow rows are more efficient with plant spacing and water uptake, which means twins may handle higher populations," Bauer says. "The variability we see in soils emphasizes the potential of variable-rate population in twin rows to match the soil’s productivity."

Fungicide Timing

As the motivation to control diseases and the concept of plant health become more widespread, farmers are asking if they should move or split their fungicide applications in corn to include a treatment at V5, which is early in the season with corn at five-collar development.

p43 Test Plot Roundup Chart"With any fungicide application, farmers should keep in mind the disease triangle—host, pathogen and environment," Bauer says. "This, along with hybrid susceptibility, will help guide any application decision. But we have gotten more questions about fungicide timing at R1 [silking] and V5."

This past year was the second year of trials for Bauer, and field tests were conducted in irrigated corn-on-corn fields, which is the environment where you would expect a higher response to fungicide application. This was a split hybrid trial with one hybrid having a higher susceptibility score to Northern corn leaf blight, which was the primary disease challenge for that year. The fungicide used in the trial was Bayer Stratego YLD.

"In both years, when we did applications at both timings, the two applications did not have an additive effect to yield," Bauer says. "With single applications, our most consistent responses have been with R1 treatments, and the responses have been less consistent at V5."

In 2010, three of the four test plots had a yield response to an application at V5, and in 2011, one of the two test plots had a yield response to application at V5.

Bauer notes that a hybrid’s susceptibility and genetic responses to fungicide play a role in its timing responses.

"That said, if you are scouting early in the season and see diseases, you need to pay attention to thresholds and pull the trigger to spray," she says. "We’ll continue to look at these methods and learn more as we go forward."

Vertical Tillage for Soybeans

Many farmers no-till soybeans after corn, but Bauer often gets questions from farmers about whether adding a vertical tillage pass in the spring can improve yields.

"One of the things farmers struggle with is stand establishment in no-till," she explains. "Even in the 15" soybean rows, our goal is to plant in between the old corn rows, but the closer we are to the old row, the more of a struggle it can become. We’ve also tried to plant at an angle, which has helped improve things, but we still lose some stand when we cross the old corn row."

That sparked Bauer to run a series of test plots examining how springtime tillage can be a tool for farmers. In 2011, the second year for the plots, she used the following tools: the Great Plains Turbo-Till, the Great Plains Turbo-Chopper, the Landoll VT Plus and the Salford Residue
Tillage Specialist (RTS).

Bauer reports advantages at planting and at harvest with a spring harrow vertical tillage pass.
"We typically have seen an improvement in final stand counts when planted early in the season with cool, wet conditions where vertical tillage tools were run versus no-till," she says. "When planting was delayed until late in the season, we have seen less improvement in stand count. We also have seen less of an effect if planting populations were high to begin with."

When population was more of a limiting factor, a harrow pass was more likely to improve final stand.

"In a year like 2011, the wet conditions pushed no-till planting into June," Bauer explains. "Then we had 1' weeds, and weed pressures can lead to insect pressures."

In this scenario, Bauer encourages farmers to run harrows as another tool in their toolbox to help with the conditions they are battling.

The yield advantage of having run vertical tillage harrows was an average of almost 2 bu. in 2010 and 3.6 bu. in 2011.

"Farmers tend to think they have been overplanting and that reducing populations could help with branching and pod set," Bauer says. "But they need to keep in mind that if they start with fewer plants, it’s even more important to protect their final stand and tighten the ratio of planted population to stand count."

Harvest Grain Cart
Each Farm Journal Test Plot is harvested using a calibrated yield monitor, and yields are double-checked with a grain cart outfitted with scales.

Easier harvest. A vertical tillage harrow is designed to work the soil a couple of inches deep while sizing residue and not leaving a horizontal layer. Compared with other tools, it keeps residue on the surface.

Farmers are reporting easier harvest over the ground where a harrow was run.

"When there was a heavy dew, I was able to harvest the soybeans where the harrows were run up to an hour before the no-till ground," says Terry Finegan, a farmer from Jonesville, Mich. "At night, if a dew is coming on, I can stay in the field longer. I’ve seen the same results if I shred the cornstalks, in that if you are able to knock down the stalks, you don’t have wet stalks that won’t slide on the grain table and you are reducing the amount of material being cut by your platform and processed through your combine."

Bauer says she’ll expand her work on how residue management plays a role in the soybean crop.
"We are going to continue to look at how harrows can help farmers achieve higher soybean yields and make harvest easier," she says.

Corn Nematode Control

Field trials conducted in Indiana and Michigan in 2011 provided the second year of testing for corn nematode seed treatments currently on the market.

Corn nematodes have been reported to be increasing in pressure, and most yield damage is done in areas with high populations of harmful nematodes, called hot spots.

"One of our goals is to see if we can get a consistent response from the controls available to farmers," Bauer says, noting that it’s important to understand a field’s nematode pressures.

"Nematode testing through soil and plant samples is the best way to confirm the types of corn nematodes you have and the levels of pressure. We use yield maps and in-season NDVI aerial mapping to help direct this sampling," she explains.

Bauer planted test plots using Avicta on NK seed and Votivo on AgriGold seed products. The check in the Avicta plot was treated with Cruiser insecticide, and the check in the Votivo plot was treated with Poncho insecticide.

Healthy roots. "Compared with previous studies, this year we had less variability in our results when using Avicta- or Votivo-treated seed in known moderate to high-pressure areas of the field," Bauer says. "The root systems were healthier in the treated areas and more root hairs were on the plants of treated seed."

p46 Test Plot Roundup Chart2

In the heavy and moderate pressure zones, yields improved from 1 bu. to 21 bu., with an average response of 4.6 bu., at one site, and from 1.1 bu. to 9.7 bu, with an average of 5.4 bu., at the second test plot location.

Bauer says she believes the yield increases in the treated areas come from protecting the roots from nematode feeding, and particularly from improving the crown roots. The crown roots are very important in the yield potential of the corn plants, and having healthy first, second and third sets of crown roots can lead to improved yields.

"It’s important for farmers to know their nematode pressures," she says. "So far, our research does not show responses in areas with only low amounts of pressure."


Test Plots LogoThank You to Our Test Plot Partners

Our thanks go to: Case IH and Tom Dean; Archbold Equipment and Bill Roth; OmniSTAR and John Pointon; New Holland, Sean Dorosz and Gene Hemphill; Challenger and Mike Alvin; Farm Depot and Mark Laethem; Great Plains, Tom Evans, John Sites and Doug Jennings; Syngenta, Cliff Watrin, Palle Pedersen, Joe Kuznia and Peter Lex; AgriGold and Mike Kavanaugh; Wells Equipment and Darrell Avery; Landoll and Corey Hyde; Salford and Jim Boak; Orthman Manufacturing and John Bell; Bayer CropScience and Dennis Clark; GeoVantage and Nick Morrow; Terry Finegan; Bob and Mary Kochendorfer; Leon Knirk; Bob Miner; North Concord Farms; Stamp Farms; Weston Wiler; Willibey Bros.; B&M Crop Consulting.



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