Agronomy Notebook

By Dave Nanda, Ph.D., Seed Genetics Direct director of genetics

With all the bad news about the coronavirus this year, we need a miracle. It is really a miracle of nature that a puny little seedling can grow into a big, tall corn plant within a couple of months. The most crucial time in the life of a corn plant is the seedling stage. If we understand how our crops grow, we can do a better job of meeting their needs and improve the odds for getting higher yields. Let’s look at what happens as the young corn plants develop.

Stage V1 to V2 — corn seedlings need 110 to 120 growing degrees to germinate and emerge. The seedlings emerge when coleoptile, the spear-like leaf, pierces thru the ground. First and second leaves develop six to seven days after the seedlings emerge. The first roots start to supply water and nutrients to the young seedlings.… Continue reading

By John Schoenhals, Pioneer Field Agronomist, Northern Ohio

Springtime in Ohio is an exciting time — color returns to fields, lawns, and landscapes, outdoor activities (with appropriate social distancing) can begin, and the sound of birds fills the early morning air. When it comes to fieldwork, spring is a pivotal time for setting corn and soybean yield potential.

While seed genetics, weather, planter calibration, and overall uniformity have a high impact on yield, it is important not to lose sight of the challenges of weeds to a grower’s operation.

The challenges that weeds pose to growing crops has increased drastically in recent years, and 2020 will bring even more challenges. Large amounts of prevent plant ground in 2019 allowed tough-to-control weeds such as marestail, ragweed, and waterhemp to produce enormous amounts of seeds. These seeds can very quickly be spread to new areas.

Waterhemp is the newest weed threat in many parts of the state, especially in soybean production.… Continue reading

By Matt Hutcheson, CCA, Product Manager, Seed Consultants, Inc.

Following a wet growing season in 2019, some of the issues facing growers in 2020 are lingering from the previous growing season.

Due to the excessively wet weather in the spring of 2019, many fields have compaction that will impact crop development and yields for years to come. Growers should alleviate compaction when conditions allow. Tillage should be performed only when soil conditions are favorable. Tillage under wet or “marginal” conditions will only make compaction problems worse. Compaction is a huge yield killer, as Randall Reeder and Alan Sundermeier wrote in a recent C.O.R.N. Newsletter: “Years of OSU Extension research on Hoytville silty clay loam showed that through compaction, 10% to 15% of the potential crop yield was being left in the field.” Farmers should plan to alleviate compaction when possible and avoid traffic on wet soil this spring.

Weed control in soybeans will continue to be a challenge between herbicide tolerant weeds and the plethora of soybean herbicide traits available to growers.… Continue reading

By Matt Hutcheson, CCA, Product Manager, Seed Consultants, Inc.

For much of the Eastern Corn Belt it is widely understood that the optimal planting period is between April 20th and May 10th. Research has proven that corn loses yield potential daily when planted after the beginning of May. For the Central Corn Belt, the declines in yield potential due to planting delays vary from about 0.3% per day early in May to about 1% per day by the end of May. Knowing that this is true, it can be frustrating during a wet spring or when field work is delayed for one reason or another. Planting is a critical component of a successful crop as it sets the stage for the entire growing season. However, it is important to keep in mind that early planting is just one of many factors that contribute to high yield potential. Planting early favors high yields, but it does not guarantee them and growers should not focus entirely on the calendar.… Continue reading

By Matt Hutcheson, CCA, product manager, Seed Consultants, Inc.

As harvest wraps up in across the eastern Corn Belt and plans for the 2020 crop are finalized, growers will determine what crops to plant and plan crop rotation across their acres. When considering crop rotations and yields, many focus on continuous corn and the yield penalties associated with that practices. However, there is one possibly overlooked benefit of crop rotation: avoiding a soybean yield penalty.

In this article, the University of Kentucky’s John Grove discusses soybean yields for first year and second year soybeans from 2009 to 2016. Grove’s research data shows an average yield penalty of 2.3-bushels per acre across that 7-year period, with some years being showing yield losses greater than 10 bushels per acre. In another article from no-till farmer, Greg Roth shows data that predicts a 4- to 6- bushel per acre yield penalty for second year soybeans.… Continue reading

By Luke Schulte, Beck’s Hybrids

After enduring the spring of 2019, it will not take much convincing for many of you that precipitation extremes have become the new normal. It’s been said that if you want things to be different, just wait until next year. While this will likely be true, the trend of punishing rain events occurring more frequently is undeniable.

Impacts of extreme precipitation:

1. Intense rains with increased atmospheric moisture = persistent risk of flooding
2. Soil movement and topsoil degradation
3. Decreased aggregate stability, lower soil O2 levels
4. Sustained dry periods between rains
5. Days to perform field work are limited.

Effective water use

While excessive water at any given time has many downsides, effective water utilization is critical to overall crop development and growth. Water is a fundamental component of photosynthesis. In order to maximize this critical resource, we must implement management strategies that allow our soils to both accept and retain more water to sustain us throughout the drier periods.… Continue reading

By Matt Hutcheson, CCA, Product Manager, Seed Consultants, Inc.

As a result of the wet spring weather there was a great deal of variability in corn and soybean fields in 2019. Early rainy weather caused wet soil conditions early in the growing season, flooded areas of fields, and resulted in fields that had to be replanted. Although in many cases the saturated soil conditions stunted crop growth, in some cases compaction is to blame. Field work this spring when soils were too wet or “marginal” created yield-limiting shallow compaction, smearing of the seed furrow, etc.

In the 2012-01 issue of the C.O.R.N. Newsletter Randall Reader and Alan Sundermeier state that “Years of OSU Extension research on Hoytville silty clay loam showed that through compaction, 10% to 15% of the potential crop yield was being left in the field.” Horizontal root development and poor root development in general are indications of soil compaction.… Continue reading

By Andy Westhoven, AgriGold agronomist

Doesn’t that title sound a lot better than prevent plant ground syndrome? The words prevent plant (PP) send shivers down many growers’ backs. For those with PP acres, the season just keeps on offering new challenges. Many growers have worked the ground, sprayed the weeds, chopped the weeds, worked them again… you get the point. Let’s face it, the PP acres are more work to keep clean than the planted acres. In addition to those challenges, the title implies that idle farmland has some more work to do and there is more to watch for with PP acres leading up to next spring.

Fallow syndrome can occur when a corn (or wheat) crop is planted the year after no crop was planted in a field. These grass crops might exhibit a phosphorus (P) or zinc (Zn) deficiency early in the growing season. Plants will appear to be stunted, pale, and purple in color.… Continue reading

By Andy Westhoven, AgriGold Regional Agronomist

The 2019 growing season has certainly been one for the ages (and the record books). It has been both memorable and forgettable. I know many growers who have said this year they had to throw out the rule book. I can empathize with any grower, as I too did some things that made me embarrassed. However, this was, and still is, a year of audibles. We’ve had Plan A, B, C, D, etc. We had to be quick on our feet whenever the slightest window opened for fieldwork. Sure, many times it was questionable at best, but it’s what had to be done. Now if you’re fortunate to have a crop planted and still actively growing, I believe you have to fight to the finish line.

There are many factors now out of our control. Many crop roots are average at best, which is a major challenge.… Continue reading

By John Schoenhals, Pioneer Field Agronomist in northern Ohio

Fungicide applications to corn and soybeans is an important management practice in an “average” year, but what about in 2019, a year

in which many corn and soybean acres were planted much later than normal? To answer this question, it is important to understand the role and function of fungicides.

Leaves serve as a “factory” for the plant, collecting sunlight and carbon dioxide to produce sugars used for grainfill. Healthy leaves produce sufficient amounts of sugars to meet grainfill needs as well as support plant health.

When plant diseases are present, the efficiency of this factory is reduced. If the demand for sugars is greater than what an unhealthy plant can produce, grain yield is reduced and overall plant health will rapidly decline as cannibalization of stalks takes place.

When fungicide applications occur, the leaf “factory” is protected from further disease development for a period of at least two to three weeks.… Continue reading

By Matt Hutcheson, CCA, Product Manager, Seed Consultants, Inc.

Spring of 2019 is one everyone would soon like to forget. However, as the growing season progresses, there are several areas of crop growth and development that could be impacted because of the wet field conditions and delayed field work.

In many areas field conditions were marginal at best for the duration of April, May, and June. As a result, field work was performed in wet soils. Although many growers feel they never had adequate conditions and to perform field work, it is important to keep in mind that throughout the growing season we are going to see why agronomists warn against field work in wet soils. Root-restricting compaction is a concern this growing season and evidence of compaction’s significant impact on crop development appeared shortly after emergence of corn this year. In fields where corn was planted under wet conditions, sidewall compaction is evidenced by roots that can only grow in the direction of the seed furrow because they are unable to penetrate the sidewall of the furrow.… Continue reading

By Luke Schulte, Beck’s Hybrids

As I am writing this, many corn and soybean acres have yet to be planted throughout the state. However, my hope is that by the time you read this, your crop will have emerged and will be growing vigorously.

One thing that is certain for later planted corn is that the vegetative growth period will be expedited. By now, many of you have been made aware of the research conducted by The Ohio State University and Purdue University which has shown that, on average, a hybrid requires 6.8 GDU’s less per day to reach black layer or physiological maturity when planted after May 1. This is possible because of the accelerated accumulation of heat units or GDU’s. Instead of producing a new leaf every five to seven days prior to the V7 growth stage, later planted corn will more likely produce a new leaf every four to six days within this same period.… Continue reading

By Roy A. Ulrich, DEKALB/Asgrow technical agronomist

The long fight with Mother Nature that started in the fall with harvest rolled right into spring and never really relented. As a result, the growing season of 2019 started out by challenging the plans that growers and agronomists had developed over the winter months to produce the highest yields possible while striving for the best return per acre. While most of those plans did not include a mid- to late-May and into June planting dates for corn and soybeans, that is when some growers finally found a dry period to put crops in the ground. Now is the time to reexamine those plans to see which of the yield determining factors could still have a positive influence on the corn crop in 2019.

After all, according to Dr. Bob Nielson from Purdue University only “12 to 16% of the overall yield variability is actually impacted by the delayed planting date.”… Continue reading

By Matt Hutcheson, CCA, Product Manager, Seed Consultants, Inc.

Uniform corn emergence is one of the most important aspects of stand establishment and producing high yielding corn. Understanding germination, emergence, and how environmental factors influence these processes is the first step toward ensure uniform emergence.

Germination

Germination begins in a corn seed when it has imbibed 30% of its weight in water. While corn can germinate when soil temperatures are 50 degrees F or higher, research has determined that the optimal temperature is 86 degrees F. Visual signs that corn germination is taking place are the appearance of the radicle root, coleoptile, and seminal roots. When temperatures are cooler, the germination process is slower and seedlings are more susceptible to disease, insects, and other damaging factors.

Emergence

Uniform emergence is one of the most important yield-influencing factors that growers should work to achieve. Delayed emergence can ultimately result in diminished yield.… Continue reading

By Matt Hutcheson, CCA, product manager, Seed Consultants, Inc.

For much of the eastern Corn Belt, it has been too wet to plant this spring. However, in some areas corn has been planted is emerging or in the early growth stages of development. One phenomenon that commonly occurs at the early stages of the growing season is the appearance of purple corn plants. Corn plants can turn purple for several reasons related to environmental factors such as:

• Sunny days and cool nights (temps in the 40s to 50s F)
• Soil pH lower than 5.5
• Cool temperatures
• Wet soil
• Stresses that hinder the uptake of phosphorus
• Herbicide injury
• Soil compaction.

Because many fields have saturated soils and the forecast includes cooler nights and continued wet weather, producers may see some purple plants in their fields. Purpling in corn due to cooler weather most often occurs when plants are in the V2 to V5 growth stages.… Continue reading

By Andy Westhoven, AgriGold regional agronomist

At this point in the calendar, undoubtedly, there are many corn fields planted around the area. Just as undoubtedly, planting conditions will be like the story of Goldilocks and the Three Bears — some will be too cold and wet, some too hot and dry, and some just right. The role as an agronomist usually travels down the road of the first two situations in Goldilocks’ tale — less than ideal planting conditions. Somewhere in the eastern Corn Belt, after a corn field has been planted, a torrential rainfall will occur and/or there will be a cold period where a grower might wonder, “What is to become of the corn seed I just planted? How long can it last in the soil before rotting and dying?”

Last season almost gave growers a false impression of corn emergence when most fields emerged in about 8 days.… Continue reading

By Matt Hutcheson, CCA, Product Manager, Seed Consultants, Inc.

In many areas of the Eastern Corn belt planting has been delayed due to wet spring weather. With the continued planting delays some growers may begin to wonder if they should switch to earlier maturing hybrids.

When considering late-planted corn, it is important to keep in mind that hybrids can adjust the amount of Growing Degree Days required to reach maturity. In this C.O.R.N Newsletter Article, Ohio State’s Peter Thomison states: “In Ohio and Indiana, we’ve observed decreases in required heat units from planting to kernel black layer which average about 6.8 growing degree days (GDDs) per day of delayed planting. Therefore a hybrid rated at 2800 GDDs with normal planting dates (i.e. late April or early May) may require slightly less than 2600 GDDs when planted in late May or early June, i.e. a 30 day delay in planting may result in a hybrid maturing in 204 fewer GDDs (30 days multiplied by 6.8 GDDs per day).”… Continue reading

By Matt Hutcheson, CCA, Product Manager, Seed Consultants, Inc.

Two aspects of stand establishment in corn often discussed by agronomists are emergence and seed spacing. “Picket fence” spacing in corn allows plants to grow efficiently while minimizing competition between them. More importantly to achieving high yields, however, is uniform emergence. Plants that are just one leaf collar behind (due to uneven emergence) significantly reduce yield. According to Paul Jasa, University of Nebraska Extension ag engineer, “When a plant develops ahead of its neighbor, it hurts yield dramatically. It’s going to vary somewhat from year to year, but a plant lagging behind those around it becomes a weed.”

Uniform emergence is critical to maximizing yield potential. To achieve uniform emergence, several factors must be taken into consideration.

Soil moisture

Soil moisture at planting is an important part in ensuring uniform emergence. Seed should be planted into enough moisture to allow for germination.… Continue reading

Matt Hutcheson, CCA, Product Manager, Seed Consultants, Inc.

A great deal of field work has been done over the past few weeks. As corn is being planted across the eastern Corn Belt and another growing season has begun, it will be time to walk and scout fields. Once corn is planted, the next critical event will be uniform emergence. Many producers have read or heard that it takes about 100 to 120 Growing Degree Days (GDDs) for corn to emerge, but what does that mean?

A GDD (also referred to as Growing Degree Units) is a calculation based on daily high and low temperatures. This calculation helps to predict stages of growth in corn based on an accumulation of heat units or GDDs. The basic formula for calculating GDDs is: add the daily maximum temperature to the daily minimum, divide by 2, then subtract 50. The value calculated by this formula is the total number of GDDs accumulated in one day.… Continue reading

By Kyle Poling, Pioneer Hi-Bred Field Agronomist

“Variability” is not a word any farmer wants to use to describe one of their corn fields. While uniformity during the periods of germination, emergence, and nodal root formation is the goal, there are many management practices and environmental conditions that can impact this objective.

Corn germination is triggered by absorption of water. Corn kernels must absorb approximately 30% of their weight in water before the germination process begins. A seeding depth of 2 inches has often been found to provide the most consistent combination of moisture, temperature, and seed-to-soil contact for uniform germination and emergence. Inadequate seed-to-soil contact, a dry seedbed, or a rapidly drying seed zone may provide less than optimum absorption of water, causing the germination process to slow or stop completely. Additionally, corn kernels that absorb excessively cold water (less than 50 degrees F) during the first 24 to 48 hours of germination may experience serious injury or death, resulting in erratic emergence.… Continue reading