Combining plot efforts with one common goal—to increase soybean yields—Farm Journal Field Agronomists Ken Ferrie and Missy Bauer continued multiyear efforts in central Illinois and southern Michigan to evaluate multiple factors that affect yield components. In 2014, the trials included soybean cyst nematode, how to control white mold and evaluating if starter fertilizer pays in yield.
To advance their soybean research, the team also conducted several first-year field trials. Those trials included using a land roller to evaluate timing of stress during critical growth stages as well as fungicide and insecticide plots. Most of the plot efforts will continue this spring.
Treatments Play a Role in Fighting Cyst Nematode
The Farm Journal Test Plots continue to evaluate the No. 1 soybean pathogen—soybean cyst nematode (SCN). With the ability to reduce yields up to 50%, Farm Journal Field Agronomists Ken Ferrie and Missy Bauer are devoted to researching the small parasitic roundworm. In partnership with Syngenta, Ferrie and Bauer conducted field trials to study the effects of Clariva Complete Beans, a biological nematicide seed treatment.
Clariva Complete Beans seed treatment is a SCN protection option that provides season-long activity. Clariva kills SCN, independent of environmental conditions. Along with SCN activity, the impact from associated SCN diseases, such as sudden death syndrome (SDS) and brown stem rot, is also reduced. Clariva adds the
SCN/SDS protection on top of the early season insect and disease protection from CruiserMaxx Beans with Vibrance seed treatment.
The Illinois field trial evaluating SCN genetics and treatments included a soybean-following-corn rotation with pockets of high SCN pressure. The protocol included two varieties, one of which was SCN-resistant. Each variety included the CruiserMaxx and Vibrance treatments, but only two were treated with Clariva. All four treatments were replicated three times in the 40-acre field. The test plots crew pulled soil samples prior to planting to evaluate the various pressures in each field. Throughout the growing season, they also monitored root growth and plant growth.
When evaluating the effect of the Clariva seed treatment in Illinois, there was a 2 bu. response to the SCN-resistant variety with Clariva in areas of high pressures compared to the non-treated SCN-resistant variety. Both the non-cyst and cyst-resistant varieties in high to moderate pressures yielded 1 bu. to 4 bu. per acre more, respectively, with the Clariva seed treatment.
The plots also showed significant yield gains when using SCN-resistant varieties compared to SCN-susceptible varieties. In the high-pressure areas, the SCN-resistant variety received a 20 bu. per acre yield gain compared to the SCN-susceptible variety. This spike in yield shows how genetics come into play in the hot spots for SCN pressures in the field.
To best manage the varying pressures, Ferrie says to start by identifying, measuring and mapping the hot spots in your fields. This includes ground truthing the areas that show up on NDVI or thermal mapping.
“Knowing your problem areas within a field helps drive management practices,” Ferrie says. “Follow sampling procedures to measure pressures and inspect soybean roots for damage or the presence of female nematodes.”
Farm Journal Associate Field Agronomist Missy Bauer used similar protocols in two field trials in southern Michigan, comparing SCN-resistant and SCN-susceptible varieties with Clariva. All four treatments were replicated three times within the field.
In the first field in Michigan, the plots yielded 4.4 bu. more on average using a SCN-resistant variety with Clariva in low SCN pressures compared to the SCN-susceptible variety with Clariva. The results show even when cyst nematode pressure is low, there are benefits to improving genetics and using a seed treatment.
The second field location had low SCN pressures and the test plots crew did not see any visible root problems. This field location received no significant yield advantage to the SCN-resistant and SCN-susceptible soybeans with Clariva seed treatment.
Ferrie and Bauer suggest using all the tools in your agronomic toolbox to fight SCN. These management tools include: genetics, seed treatments, crop rotation and possibly cover crops.
Big Soybeans Don’t Always Equal More Yield
Aggressive growth on the front end of soybeans does not always guarantee high yields, warns Farm Journal Field Agronomist Ken Ferrie. This past spring, the team in central Illinois continued to research the role of starter fertilizer and additives in soybeans and advanced their research by incorporating potassium nitrate.
The Farm Journal Test Plots crew partnered with Syngenta to study the effects of genetics and treatments when fighting soybean cyst nematode. Photo: Darrell Smith
The no-till, soybean-following-corn field was planted in 30" rows. The crew used a Kinze 8-row planter outfitted with Schaffert Generation 2 fertilizer disks for 2x2 applications. The Schaffert attachment cuts a trench 2" away from the seed and uses an injection nozzle to apply fertilizer.
The field trial evaluated three potassium nitrate rates at 10 gal. (2.83-0-10), 20-gal. (5.6-0-20) and 25 gal. (7-0-25), then compared to 15 gal. 7-22-5 1 zinc (10.5-33-7.5). All applications were applied 2x2 and replicated three times in the field.
In the Catlin silt loam, the 10-gal. and 20-gal. potassium nitrate passes yielded more than the check, which was enough to pay for the potassium nitrate. In the Birkbeck silt loam, there were no significant yield increases; therefore, the yield did not pay for the potassium nitrate.
Across the entire field, most management zones received positive responses to the potassium nitrate passes.
“Although we saw positive responses, the ability to pay for the potassium nitrate in central Illinois was inconsistent,” Ferrie says.
In central Illinois, starter is not necessarily required to get early soybean growth, especially compared to the strong effects of starters in states such as Iowa or Minnesota, he adds.
Although the responses might not pay in certain regions, Ferrie says it’s critical to evaluate the physical symptoms of using starter fertilizer.
“Knowing what nutrients bring to the table is important,” Ferrie says. “Phosphorus shows height and cell division, nitrogen brings a change in color and potassium plays a role in plant health and water management.”
The potassium nitrate rates did not include phosphorus, which created a darker bean. The phosphorus treatment created the bigger, taller plants.
Be Proactive and Beat White Mold
The taller, bigger soybeans at the top of the photo had higher rates of phosphorus providing additional height. Photo: Darrell Smith
The key to winning the battle against white mold lies in preventative control measures. Once the infection appears, it is too late to take corrective measures. The infection happens at the flowering stage, and the physical symptoms do not appear until later in the season. Farm Journal Associate Field Agronomist Missy Bauer knows the devastating effects of white mold. In southern Michigan, the field conditions are often cool and moist, which are favorable for the disease to thrive.
In the third and final year, Bauer continued to learn more about applications that can help suppress white mold. It’s important to note, this was the first year Bauer evaluated double fungicides. At Farm Site #1, three treatments were applied in various combinations and as single applications:
- Proline fungicide from Bayer CropScience was applied at 3 oz. per acre at R1 followed by Stratego YLD fungicide also from Bayer CropScience at 4 oz. per acre at R3.
- Cobra herbicide from Valent was applied at 8 oz. per acre at the late V stage. This application was followed by Priaxor fungicide from BASF applied at 4 oz. per acre at R2 to R3.
- Contans, a soil-applied preventative fungicide from SipcamAdvan, controls Sclerotinia diseases. It was applied preplant at 1 lb. per acre and incorporated using tillage or irrigation.
At Farm Site #1, in irrigated soybeans, the Proline followed by Stratego YLD and the Cobra followed by Priaxor treatments yielded similar gains at around 4 bu. per acre. The Contans treatment followed with a 2.2 bu. gain. In this location, more than 24% of the soybean plants were infested in the hot spot areas. The Contans treatment had 13% infection; Cobra plus Priaxor had 10% infection; and Proline plus
Stratego YLD had 11% infection.
At Farm Site #2, the first two treatments (see bullet points) from Farm Site #1 were used in addition to Cobra as a single application.
In irrigated soybeans at Farm Site #2, the Proline followed by Stratego YLD yielded 4.5 bu. per acre more than the control. The Cobra followed by Priaxor followed with a 2 bu. per acre increase. At this location, more than 50% of the soybean plants were infested in the hot spot areas. The Cobra treatment had 17% infection; Cobra plus Priaxor had 17% infection; and Proline plus Stratego YLD had 22% infection.
Across three years of white mold studies using Contans and Cobra followed by a fungicide, the field trials found an average 2 bu. with Contans and an average 3.4 bu. gain with Cobra followed by a fungicide. Bauer plans to continue double fungicides studies.
When dealing with white mold pressure, Bauer recommends the following:
1 Variety selection. Evaluate field history and make your variety selection based on past performance. If prone to white mold, select a variety with stronger genetics.
2 Manage population. Research shows a link between an increase in population and an increase of in-canopy humidity resulting in higher white mold pressures. Try to keep population moderate if there is heavy potential for white mold.
3 Use variable rate. Low ground often has bigger soybean plants, which results in high humidity in-canopy and more white mold. Try variable rate to lower populations in these areas.
Make Fungicides and Insecticides Pay
In a year with tight margins, all applications need to foot the bill. No one understands that more than Farm Journal Field Agronomist Ken Ferrie and the test plots crew.
All Farm Journal Test Plots follow strict protocols to collect data. The results are verified using calibrated yield monitors and weighed with grain carts with scales. Photo: B&M Crop Consulting
In 2014, the Illinois test plots team evaluated fungicide and insecticide applications in five field trials. These field trials fall under a proactive approach to pest management.
At the time of the fungicide and insecticide applications, there was no insect pressure and little disease. With the coldest winter on record in Illinois, the insect populations naturally decreased and were noticeably lower. For example, the bean leaf beetle threat was significantly diminished in central Illinois. The relative humidity was also lower in the first part of the growing season and clean from disease. In this type of environment, applications are considered more preventative maintenance in terms of fungicides and insecticides.
Even with little pressure, the field trial still received a slight yield response. Across all three repetitions in the field, the Quadris fungicide with Endigo insecticide, both from Syngenta, received yield gains up to roughly 2 bu. per acre compared with the control.
Ferrie notes it’s uncertain whether the yield response was due to the insecticide or fungicide. In past research, he has seen a stronger response when insecticide is mixed with a fungicide. Although there was a slight yield response, it was not strong enough to pay the bill.
Ferrie and crew also evaluated four other fungicide and insecticide plots in three separate Illinois counties. These applications included a Fortix fungicide and a Declare insecticide by
Cheminova. Across all four locations, yield increases ranged from 2 bu. to 3.5 bu. per acre.
Ferrie reminds farmers that insects and diseases are controlled by the local environment. Therefore, this particular growing environment and pest pressures were specific to central Illinois and not the rest of the country.
Take note: In this instance, taking preventative maintenance measures is different than trying to control an outbreak. It’s essential to ground truth and scout fields for problem areas throughout the growing season.
“With a drop in commodity prices, you have to be more diligent in scouting. No longer does 2 bu. per acre pay the bill,” Ferrie says. “However, don’t risk giving up 10 bu. to 15 bu. if you don’t control an outbreak—specifically with spider mites or aphids.”
Stress at Critical Growth Stages Yields Results
In the first year of study, Farm Journal Associate Field Agronomist Missy Bauer conducted soybean stress plots using a land roller. Each location compared rolling at different combinations of timings including pre-plant, post plant, early V-stage and late V-stage.
In Coldwater, Mich., the field trials received benefits from rolling, including yield gains from stressing the plant, burying rocks and improving harvestability. Photo: B&M Crop Consulting
The five farm sites included three repetitions comparing the following:
- Farm Site #1: V2, control, conventional tillage
- Farm Site #2: V1.5, post-plant, control, conventional tillage
- Farm Site #3: V1, post-plant, V3, control, vertical tillage
- Farm Site #4: V1, control, no-till
- Farm Site #5: Pre-plant, post-plant, V1, control, no-till
Across all five locations, the field trials showed an average 2.4 bu. per acre boost from rolling during early V-stages, including V1 and V2. This early season plant stress changes the overall structure of the plant, according to Bauer.
“The goal of the study is to evaluate if stressing the plant early causes yield gains,” Bauer says. “We found the early stress caused the soybean plant to bush out and shorten the nodes, which allows for more pods per plant.”
Bauer notes the yield gains at post-plant and early V-stages allows for a wider window of opportunity to roll soybeans and still receive yield boosts.
Although the soybeans proved a yield gain, Bauer says the test plots crew did evaluate and monitor bent or broken soybean plants during the V-stage rolling.
“Although some plants did break, they broke above the cotyledons, which allows for two more growing points to keep the plant growing,” Bauer says.
The roller study will continue for its second year this spring at the southern Michigan location. Bauer plans to pull pod counts to evaluate where the yield gains occur from stress.
Farm Journal Field Agronomist Ken Ferrie will join the effort in central Illinois and conduct similar roller field trials this spring.