ASK THE AGRONOMIST BLOG

Each year, Stine’s agronomy team is tasked with planting and monitoring our corn and soybean plots throughout the U.S. These plots are typically planted for a few different purposes: 1. To showcase our products to our grower customers in real time; 2. To use as educational resources for our sales representatives; 3. To research product data and evaluate performance in specific environments; and 4. To test how our experimental products perform before they launch in the market.

As Stine’s director of agronomy, Tom Larson’s No. 1 goal for all our sales reps is to better understand the products we have in the pipeline.

“Previously, we were typically focused more on monitoring our current products through our corn and soybean plot program. Now, we’re testing Product Development Plots, which will include 80% new material. We hope this will give us a better understanding of how these products perform in different environments before they’re commercialized.”

PRODUCT DEVELOPMENT PLOTS (CORN AND SOYBEANS)

The purpose of our Product Development Plots is to evaluate high-yielding corn hybrids and soybean varieties from our Elite Yield Trials in addition to competitor products before commercialization. The information gleaned from these plots will aid in selecting future products.

Corn Product Development Plots are planted by height and maturity at a minimum of 12-row plots with the center six rows harvested. These plots are a minimum of 300 feet in length. We employ flag emergence studies at each plot, which helps us evaluate emergence and season-long performance. We have glyphosate and non-glyphosate products, and all corn plots will have two competitor products listed as EXP.

Soybean Product Development Plots are planted by maturity, with a minimum of eight rows and a plot length of at least 400 feet. The planting population is capped at 140,000 plants per acre per plot. We also have two competitive products listed for each soybean plot as EXP.

Specific agronomic data collected in these plots will include disease ratings; general plant observations; plant, ear, leaf and tassel height (in corn); silking (in corn) and pollination dates; test weight, moisture and yield; and harvestable ear percentage (in corn). These plots also help train our regional sales agronomists.

“At the end of the season, we’ll have reviewed 80 different agronomic attributes on each product,” said Larson.

OTHER CORN AND SOYBEAN PLOTS

Success Plots (Corn and Soybeans)

Our Success Plots are planted to train our sales team and for general observation by our grower customers, dealers and prospective customers. We don’t tabulate yield with these plots; rather, they are made available so those interested can see what the products look like in their local environment.  

We have both corn and soybean plots in our Success Plots Program. These typically showcase no more than four rows of different Stine^® products and a competitive product or two. Both corn and soybean plots are planted by relative maturity and population percentage. We use similar maturity, traits and features in both corn and soybean plots.  

Seed Treatment Trials (Corn)

“Through our Seed Treatment Trials, our goal is to test how different treatments perform with our corn seed,” says Larson.
“And we’re not putting treatment packages on top of already treated seed. We’re using bare seed — seed that hasn’t been touched by any other products.”

The data collected from our Seed Treatment Trials allows us to provide growers with more scientific information about how specific corn treatments perform under certain conditions, including weather elements, variable soils, and heavy disease and insect pressure.

Side-by-Side Comparison Plots

These plots are actually planted by our grower customers. While not technically plots, they provide growers a more holistic view of how a Stine product stands up to competitors. Our Side-by-Side Comparison Plots can have up to 20 acres of each product, which is usually a Stine product planted next to a competitor product of similar maturity and features. We work with our growers to employ these plots if they plant 100% Stine seed.

Farm Progress Show Plot (Corn and Soybeans)

The Farm Progress Show will be held in Decatur, Illinois, this year from Aug. 29–31. We planted our annual show plot on May 2, courtesy of Stine grower customer and Farm Progress Show host David Brix. The plot contains four corn hybrids, including MX441-G, MX601-G (new), MX710-G and 9817-30. For soybeans, we also planted four: 28EG29 (new), 33EG02 (new), 37EG23 (new) and 39EC22. 

“This year’s Farm Progress Show plot will have some short-stature corn products,” says Larson. “We look forward to showing attendees the difference in height with this material, as well as their overall performance and standability.”

HOW DO I SET UP A TOUR OF A STINE CORN OR SOYBEAN PLOT THIS SUMMER?

Viewing one of our corn and soybean plots this summer is as easy as contacting your local Stine sales rep. If you don’t have their information, use our Find Stine tool on our website or locate your nearest regional sales agronomist or Stine seed dealer.

A recent article by Farm Journal titled “Seize Your Corn Yield Potential with Sulfur’s Amazing Superpowers” highlights sulfur’s use in agriculture and its supporting role with nitrogen in crop production. We at Stine have always stressed the importance of sulfur as part of a super management approach to nutrient management.

“Without adequate amounts of sulfur, it becomes increasingly difficult to achieve top-end yields,” says Brian Hartman, Stine’s national corn product manager. “While the three main players in nutrient management tend to be nitrogen, phosphorus and potassium, sulfur is just as important. It works in tandem with nitrogen, so we always recommend growers consider sulfur if they’re applying nitrogen.”

WHAT IS THE ROLE OF SULFUR IN PLANTS?

The role of sulfur in plants is important to chlorophyll production and photosynthesis. Essentially, it helps convert sunlight into energy and supports the plant’s nutrient uptake.

“Sulfur has a direct role with nitrogen; it helps metabolize nitrogen, which also happens to be the No. 1 nutrient in crop production,” says Hartman. “Sulfur is also known to help protect crops from disease. They call this S-dependent resistance.”

Farm Journal Field Agronomist Ken Ferrie notes that sulfur and nitrogen are “structure-building components, so sulfur (like nitrogen) is required early in the season. The plant needs sulfur to build the factory that will produce the fruit.” He explains that insufficient sulfur will result in stunted plant growth or delayed crop maturity.

Sulfur is a macronutrient, so plants deplete it in larger quantities. Typically located in the organic matter of the soil, it cannot be translocated through the roots to the rest of the plant until it has mineralized and converted to sulfate. Then, the nutrient is mobile and acts like nitrogen. To mineralize sulfur into its sulfate form, organic material makeup in the soil must decompose. If this doesn’t happen, that’s when sulfur deficiency can occur.

DEFICIENCY OF SULFUR IN PLANTS

Sulfur deficiency can closely mirror nitrogen deficiency, so it’s important when conducting soil samples to ask the labs to also test for sulfur. There are a few different reasons why your soil may lack sulfur, including taking out the previous year’s crop.

“Harvest can remove approximately 8 to 17 pounds of sulfur per 100 bushels of corn,” says Hartman. “For soybeans, it can remove approximately .2 pounds per bushel. You need to put sulfur back in to replace what you took out with the previous crop.”

Ferrie notes in the Farm Journal article that a 200-bushel corn crop can remove up to 34 pounds of sulfur per acre.

Reduced greenhouse gas emissions are also suspected to cause deficiency as less sulfur dioxide in the atmosphere means less sulfur is deposited back into the soil. Roughly 20 years ago, we may have gotten about 70 to 90 pounds of sulfur per acre from the atmosphere. Now, with the controlling of air pollution, we receive about five pounds per acre.

The evolution to more plants per acre is also a factor.

“The higher the planting populations and the more plants you have per acre, the more nutrients are consumed,” says Hartman. “While we still encourage planting in high-population environments as it equates to higher yields, we also recommend a super management approach that includes applying additional sulfur to support this increase.”

Deficiency symptoms of sulfur in plants

Experts from the Iowa State University Extension and Outreach note that deficiency symptoms of sulfur are sometimes mistaken for nitrogen deficiency. Classic symptoms of nitrogen deficiency include “yellowing of lower (older) leaves, from the leaf tip to the base down the midrib.” In sulfur deficiency, symptoms include “yellowing of new leaves (in the whorl, sometimes with interveinal striping), with lower (older) leaves remaining uniform green.”

HOW TO APPLY SULFUR TO PLANTS

Start with soil sampling. Sometimes, labs will not test for sulfur, so you must request a sulfur test with your regular nutrient test. From there, soil fertility specialists recommend amounts to include in your application. Right now, recommendations would be for in-season applications of sulfur.

Sulfur can be applied to plants in a few different ways. 

In-season. Getting the sulfur to the plant as soon as it needs it is imperative. Corn takes up 38% of sulfur during the final three stages of growth. Consider a side-dress or over-the-top application with rates of phosphorus, potassium and nitrogen along with the sulfur. Sulfur should always be added to an in-season nitrogen fertilizer application.

Fall application. Put back what you take out after harvest with a fall soil application. This allows the nutrients more time to break down into the sulfate form to use with next year’s crop. Our experts recommend using ammonium sulfate or ammonium thiosulfate at one pound for every five to 10 pounds of nitrogen.

To learn more about the value of sulfur in crop production, contact your local Stine® agronomist or sales rep for more information.

With 83% of the nation’s soybean crop in the ground and 56% emerged, growers need to research and prepare for common soybean diseases that could affect their crops throughout the busy growing season. It’s never too early to get ahead of these potentially yield-robbing threats to your soybean acres.

“Growers need to be prepared for the possibility of losing soybean yield to diseases,” says Tom Larson, Stine’s director of agronomy. “Last year, for example, 4.4% of the potential estimated soybean production was lost due to diseases. From stem and root rots to leaf blights, it’s important to be proactive throughout the growing season to get ahead of these common problems in soybean production.”

WHAT ARE THE MAJOR DISEASES OF SOYBEANS?

Sclerotinia stem rot (white mold), sudden death syndrome (SDS), charcoal rot and Phytophthora leaf and stem rot are some of the most common soybean diseases. Combined, these four soybean stem diseases destroyed almost 45 million bushels in 2022. Other diseases (leaf and aboveground), such as Cercospora leaf blight, frogeye leaf spot and Septoria brown rot, damaged close to 13 million bushels last year. It’s critical to understand the environments these diseases thrive in and how you can prevent them, if not this year, then the next.   

SOYBEAN DISEASE IDENTIFICATION AND CONTROL

Soybean disease identification can help protect your soil and crops to produce maximum yield this growing season.   

Named the leading soybean stem disease in 2022, soybean sudden death syndrome symptoms can appear between R1 and R6 growing stages as random yellow spots between leaf veins. Other SDS symptoms include soft, rotten roots; stem discoloration; necrosis of the leaf tissue between the veins; yellowing of leaves; and leaf drop. While infection of roots may occur early in the season, symptoms usually don’t develop until late July or August. The disease prefers cool, wet soils. Planting SDS-tolerant varieties is an effective way to limit your crop from developing disease. Additionally, crop rotation, tillage and the staggering of planting dates can help limit the disease.

“SDS is one of the most destructive diseases in soybeans,” says Larson. “Experts from Iowa State University Extension and Outreach conducted a study and found that, in areas with severe infestation, SDS can cause up to a 40% yield loss, especially when symptoms develop early. In 2022 alone, SDS destroyed close to 19 million bushels.”

More common in cool, humid and wet growing conditions, white mold can cause significant yield loss. Known for its fluffy white, cotton-like appearance on soybean stems, initial symptoms appear from R3 to R6 as gray to white lesions on plant stems. White mold can eventually lead to leaf death, stem rot and flower wilt. White mold overwinters in the soil and can do so for several years. Experts note it can easily spread to new fields when improperly cleaned seed is used and by the movement of infested soil.

“White mold can cause significant yield loss upwards of 10% bushel per acre,” says Larson. “We’ve seen it devastate fields. It should be a top concern for growers always, but there are ways to mitigate white mold by planting soybean varieties that offer some resistance to the disease and through crop rotation to small grains.”

Phytophthora root and stem rot of soybeans occurs in cool, wet conditions. The disease typically appear between VE and R6. A dark brown lesion on the lower stem that extends up from the taproot of the plant is the most common characteristic of the disease. Other Phytophthora root and stem rot symptoms can include yellowing of leaves, soft/rotting stems and roots and wilted plants. The disease is more severe in no-till fields or in areas that are susceptible to flooding. Tillage, seed treatments and planting resistant varieties are suggested for healthy soybean growth.

Caused by the soilborne fungus Macrophomina phaseolina, charcoal rot of soybeans issues the most damage when weather conditions are hot and dry. Early signs of charcoal rot include red to brown lesions on the roots and lower stems, which then turn to black specks. To help battle charcoal rot, planting the right variety, crop rotation and residue management can produce top yield and keep the disease at bay.

Contact your local Stine® agronomist or sales rep for more information on common soybean diseases and how to treat and prevent them now and in the future. Stine offers a full line of the industry’s most sought-after traits to help growers produce the most yield on their soybean acres.