Growing Conventional Corn 101

FBN Network

Oct 15, 2018

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With commodity corn prices in the dumps, many farmers are seriously considering growing conventional corn hybrids to reduce seed costs and keep their farms profitable. We compiled everything you need to know about growing conventional and non-GMO corn hybrids.

Conventional Corn versus Non-GMO Corn: What’s the difference?

Did you know there is a difference between traited corn, conventional corn, non-GMO corn and organic corn? Each one offers something different for your operation, and depending on your practices and the profit potential you’re looking for, one of these options might be a better fit than the others. We're diving into this and other questions about conventional corn, from chemical cost and yield consistency, to selecting the right genetics and maximizing ROI.

The terms and definitions around GMO, conventional and non-GMO can often be confusing. Here’s a short explainer on the difference:

Traited Corn (Genetically Modified Corn)

  • Any corn seed that has foreign DNA (at least one foreign input trait) added to the seed through genetic modification. The most common traits are corn borer resistance, corn rootworm resistance, and glyphosate tolerance.

  • Terms like “single stacked,” “double stacked,” “triple stacked,” etc., refer to the number of input traits added to the seed.

  • Farmers planting refuge in-a-bag (RIB) corn seed plant a mix of conventional and traited corn within the same bag. All RIB corn contains a mix of conventional corn and traited corn.

Conventional Corn
  • Any corn seed that has no foreign DNA or input traits added to the seed.

  • It is impossible to ensure that a bag of seed is 100 percent free of genetically modified material, due to unintended cross pollination during corn seed production and in the field.

  • Glyphosate and glufosinate containing herbicides should not be sprayed over the top of conventional corn. Nearly all other corn herbicides can be used on conventional corn.

Non-GMO Corn
  • Corn seed that meets a higher level of purity of being free from traits (more so than conventional corn).

  • There are additional steps that must be taken to meet contract specifications to get a premium by marketing the crop as non-GMO corn.

  • In recent years, the number of farmers growing non-GMO corn has expanded, making the availability of non-GMO contracts more scarce and reducing the size of market premiums.

  • Non-GMO corn should not be certified by a farmer as “GMO free.” Seed marketed by FBN as non-GMO or conventional corn has no detectable presence of GM traits, but may that does not assume a zero level of trait presence, as every seed cannot be tested.

Maximizing return on investment with conventional corn

Maximizing your return on investment when growing conventional corn comes down to balancing several key factors, including seed and chemical costs, yield variance and grain marketing.

We have multi-year data from more than 550 FBN network farmers who planted both conventional corn and traited corn. These insights are based on analysis on more than 200,000 acres of conventional production and more than 4 million acres of traited corn production.

Seed costs
On average, FBN network farmers who buy conventional corn seed save about $39 per acre on seed.

Many farmers choose to grow conventional corn for the seed savings alone—the savings on conventional corn seed is the most common reason we hear when asking farmers why they are switching acres to conventional corn. On average, FBN network farmers who buy conventional corn seed save about $39/acre on seed.

Chemical costs
Different plans. Not necessarily more expensive.

Switching to conventional corn does not necessarily increase your chemical costs per acre. Agronomists and farmers with experience growing conventional corn are often able to create chemical plans that are cost-neutral to the plans they create for traited corn.

A well-designed pre-emergence and post-emergence herbicide program with overlapping residual and contact herbicides can help you keep your fields clean through canopy.

Yield consistency

More than 50 percent of FBN farmers who plant conventional corn see higher yields compared to traited corn. Contrary to popular belief, growing conventional corn does not mean you should expect a yield drag. (Variety performance and individual field conditions will have the biggest impact on yield differences.)

Preplant considerations for conventional corn

There are several factors to consider before making the final decision to dedicate acres to conventional corn.

Selecting the right conventional corn genetics

There is a difference between genetics and traits for any seed variety, and the difference matters to your operation.

Corn hybrid properties and characteristics

As you would with any corn hybrid, consider the following properties and characteristics of the conventional corn hybrid you are considering, as each provides an opportunity to plant the best genetics for your acres.

Common corn hybrid properties include:

These are properties that speak directly to grain development.

  • Relative maturity: This is a number that tells you the number of days after planting that hybrid will reach black layer. There is no industry standard for reporting RM, so you should use +/- 3 days when comparing different seed company ratings.

  • Kernel rows: This describes the number of kernel rows you can expect on a certain hybrid. Keep in mind that more rows does not always mean more yield. Agronomically, a neutral factor; the number of rows of kernels on an ear—average is around 800 kernels per ear

  • Ear type: The explanation of whether ears will be a fixed size in any population, or if the size will flex as the population increases or decreases in the presence of stress

  • Test weight: This helps define weight of a bushel of grain (lb/bu). The industry standard for #2 yellow corn is 56 lbs/bu, so higher test weights take up less volume.

  • Plant height: This is a relative term and does vary by environment; generally speaking, it’s describing how tall the plant will grow to be, which is also related other factors such as canopy development.

  • Ear height: This is another term that varies by environment and region, but is generally defined as where on the plant the ears will form. For example, the higher the ear, the more attention you might want to pay to the hybrid’s overall standability.

Common corn hybrid characteristics include:

These characteristics apply to the overall corn plant.

  • Staygreen: Measures late season health, speaking to silage suitability and stalk integrity

  • Late season intactness: How well the ear and stalk hold up in the case of late harvest

  • Stalk rating: Strength and hardiness of the stalk

  • Root rating: Strength of root system

  • Emergence: How well and how quickly the corn comes up after planting

  • Early plant vigor: How quickly the plant establishes the first few vegetative stages above ground

  • Dual purpose: Works well for both grain and silage purposes

  • Minimal tillage response: How it fits into a no-till or minimum till scenario

  • High population response: How the hybrid performs at increased populations; described as 10 percent above what a grower normally plants

  • Low population response: How the hybrid performs at lower populations; low population is described as 10 percent lower than what a grower would normally plant

  • Adapts to narrow rows: How it works in decreased row spacings, specifically those less than 30 inches

  • Corn after corn: How it performs in fields where corn was planted the previous year

In-season management of conventional corn

Conventional corn agronomics

You can achieve acceptable control of weeds and insects in conventional corn.

Weed control and your chem plan

Always start with a clean seedbed—the best way to control weeds is not allowing them to emerge, and you can do this by using multiple modes of action and pre-emergence residual herbicides.

The most difficult-to-control weeds in any type of corn production are kochia, common waterhemp and marestail, and these weeds have demonstrated resistance to one or more groups of herbicides. Fields with one or more groups of resistance can make developing an effective herbicide program for corn more difficult; however, since these weeds can become resistant to glyphosate, you are not giving up much (if any) weed control by leaving the glyphosate out of your chem plan.

Common herbicides, fungicides and insecticides for conventional corn

Remember, herbicides containing glyphosate and glufosinate should not be sprayed over the top of conventional corn, but nearly all other corn herbicides can be used on conventional corn.

You can learn more about other products that may contain these active ingredients or that could be applied to conventional corn here.

In-season scouting for pests and weeds

Weed and insect scouting is an important step for growing both conventional and non-GMO corn. 

Weed scouting

Scout your field(s) throughout the growing season. Pay particularly close attention to weed pressure while weeds are emerging and small. Watch closely for noxious weeds and yield-robbing weeds such as cockleburs, pigweed, marestail,waterhemp, pokeberry, velvetleaf, balloon vine, etc. Fields should be scouted at a minimum of once a week. †

Insect scouting

If you choose to grow conventional corn, you should be scouting for European corn borer, western bean cutworm, fall armyworm and black cutworm. Conventional corn should not be planted in fields with expected corn rootworm infestations, unless a rootworm insecticide will be used.

Many farmers also choose to add a preventative insecticide application during their foliar fungicide applications for a small additional cost — if, for example, let’s say you are growing corn-on-corn or are in a known area with a rootworm variant that is active in a soybean rotation, that potential risk might warrant an insecticide application.

Fertility and nutrients

Your fertility plan for conventional corn is essentially the same as your traited corn. You can utilize soil tests and precision technology, such as variable rate applications, to make sure that you know where your crop needs nutrients throughout the season, and that you don’t over-apply or under-apply.

Prioritize your more productive fields, paying specific attention to those that see the least pressure from difficult-to-manage weeds and insects. Use a good starter fertilizer to get your stand up and established as uniformly and quickly as possible.

It’s important to be aware of your genetic potential for yield with conventional corn so that you can create the right balance in your fertilizer spend and nutrient management plan to grow the most productive crop possible. Remember, yield is about the genetics, not the traits. That’s also why transparency around parental lineage in seed is so critical.

Diseases to watch for in conventional corn

Even more important is understanding your fields disease history and choosing genetics that have good disease tolerance in addition to using a fungicide when recommended.

While the diseases that could impact your conventional corn are the same as in traited corn, it is important to know what to look for. Remember, too, that insect damage can create an entry point for a variety of corn diseases.

Here are some common corn diseases and types of diseases (both in conventional and traited corn) that you should look out for:

Leaf diseases
  • Gray leaf spot: Long, rectangular lesions; initially light tan and eventually turning gray - that are usually restricted by the leaf veins. These can grow together and eventually kill the leaves.

  • Northern leaf blight: Cigar-shaped lesions 1-6 inches long that start out a gray-green and turn grey or tan. This starts in the lower leaves

  • Goss’s wilt: Long, wet, gray-green to black lesions with wavy edges. The lesions ooze, leaving crystallized deposits on the leaf. Some plants have a slimy stalk rot and may wilt.

  • Common rust: Dark red pustules on both upper and lower leaf surfaces. This shows up in the mid- to upper-canopy

  • Southern rust: Orange pustules that cluster on the upper leaf surface. First seen in the mid to upper canopy, this disease likes hot weather and can be very aggressive

  • Fusarium: Shows up as a white/pink, cottony mold that usually begins with already damaged kernels. Infected kernels are usually tan, brown or white-streaked. The fungus produces mycotoxin.

  • Diplodia: Starts as a white mold beginning at the base of the ear but eventually rots the entire ear. This rot can sometimes be seen on the outside of the husk. Diplodia can also cause stalk problems that lead to lodging.

  • Anthracnose: Shows up as narrow, watery lesions that grow together into large, black spots on the stalk. The inside of the stalk may also be blackened..

  • Gibberella: Noticed in dark brown streaks or black dots that can be scraped off on the lower internodes. The inside of the stalk is rotted, pink and shredded.

Ear rots
  • Fusarium: Shows up as a white/pink, cottony mold that usually begins with already damaged kernels. Infected kernels are usually tan, brown or white-streaked. The fungus produces mycotoxin.

  • Diplodia: Starts as a white mold beginning at the base of the ear but eventually rots the entire ear. This rot can sometimes be seen on the outside of the husk. Diplodia can also cause stalk problems that lead to lodging.

Stalk rots 
  • Anthracnose: Shows up as narrow, watery lesions that grow together into large,  black spots on the stalk. The inside of the stalk may also be blackened.

  • Gibberella: Noticed in dark brown streaks or black dots that can be scraped off on the lower internodes. The inside of the stalk is rotted, pink and shredded. 

Harvesting conventional corn

Harvesting conventional corn is similar to harvesting traited corn. In fact, there are no special considerations or practices unique to harvesting conventional corn versus traited corn—any field planted with conventional corn should be checked and prepped for harvest in the same way as fields planted with traited corn. Be sure to make appropriate combine adjustments to reduce the potential field losses and for any volunteer corn or soybean escapes.

Markets for conventional corn

For many farmers, the markets for conventional corn are the same as those for traited corn. Conventional corn can be sold locally to supply domestic markets for ethanol and feed, or exported to international markets with unmet demand. Where exports of conventional corn are concerned, you don’t have to worry about a load of corn being rejected at delivery by the elevator because of traits that are unapproved for export or processing.

Primarily, conventional corn provides an option for farmers to reduce their seed costs and receive a cash price for their grain at delivery in the same way they would for commodity grain. But, remember, conventional corn cannot be marketed as non-GMO corn unless it has been grown under certain specifications to ensure purity of the grain.

Growing non-GMO corn to earn a premium

You may have opportunities to maximize your potential to get a premium for non-GMO corn. If you do, you will need to put in a few extra steps to maintain grain quality and meet contract specifications.

Non-GMO hybrid selection

If you’re filling a non-GMO contract that pays a premium, typical best practices can include:

  • Non-GMO tested seed that has no detection of genetic modification (traits) in the seed.

  • Seed purity greater than or equal to 96 percent.

  • Germination minimum of 90 percent.

  • Obtain a statement detail from your seed company that the seed has no detectable GM in their quality tests.

Smart field selection

Field selection is critical to maintain non-GMO purity. When making your field selection:

  • Let your neighbors know which field(s) you are planting non-GMO crops.

  • Consider harvesting a round or two from the outside of the field and marketing that corn as conventional corn, while preserving the inside of the field for the non-GM market.

  • Be aware of potential cross-pollination issues with neighboring fields. Establish buffers by using windbreaks or hedgerows to alleviate issues.

  • If possible, in order to minimize cross-pollination with GMO crops, delay your planting dates so that your non-GMO crops do not pollinate at the same time as adjoining GMO crops.

Planter settings and cleanout

If you are hoping to receive a non-GMO premium, and you are planting both traited and non-GMO grain with the same planter, make sure to follow all cleaning techniques prior to planting.

  • Inspect your planter thoroughly for any grain or dirt that is trapped inside.

  • Fully open traps to sweep out any excess seed from seed tenders if using them to load planters.

  • Check equipment manufacturer’s manual for proper operation.Planting at proper speeds is crucial to ensure a uniform crop stand and to minimize splitting for fragile seeds.

Harvesting non-GMO corn

If you are growing non-GMO corn for a premium there are just a few management differences, specifically around equipment maintenance and handling. If there are fields of traited corn nearby, you may want to harvest a full round or two to just be sure to not cause an issue that could cost you the premium.

Combine settings and cleanout

When growing non-GMO corn for a premium, grain bins, augers, truck wagons, hoppers and pits all need to be cleaned if old grain and dust are present.

  • Run augers until dry.

  • Harvest approximately 100 feet and unload the grain to clean your machine. If there are fields of GM or traited corn nearby, you may want to harvest a full round or two to just be sure to not cause an issue that could cost you the premium.

  • Clean out the combine by using compressed air to flush out. Unloading augers are the toughest to clean.

  • Keep flushed grain in a separate wagon or truck and do not sell with your non-GMO corn. (It is good to keep documentation of this to show clean out of grain).

  • You can use a broom to sweep sidewalls and floor to remove grain and dust.

Non-GMO crop storage and handling

Corn being produced for non-GMO premiums must be stored and handled separately, or segregated, from other corn hybrids and crops. This is particularly true if you are growing on a production contract, so that the grain purity can be identity preserved (IP) for the end user.

Today, farmers have more opportunities to grow conventional corn hybrids thanks to new genetics that perform well, offer a value on seed costs and help improve profit potential. 

You did it! -- You Completed Growing Conventional Corn 101!

We encourage you to go through and click on some of the links above to learn more about specific topics.

And if you want to give conventional corn a shot this year, check out our conventional corn hybrids! We're working to bring farmers closer to breeders and offering great genetics and low prices.

This information is not intended as an agronomic recommendation, nor are we making any such recommendation. Always consult an independent agronomist if you are unsure of agronomic decisions on your operation. We are not a licensed commercial or private applicator of chemicals including, without limitation, herbicide, pesticide, insecticide, rodenticide or fertilizer. All alternative products listed are only possible alternative or substitute products, and its listing in this document does not constitute a recommendation. Please consult with an independent agronomist and consider your specific field conditions (e.g,. soil type and texture, weed pressure, and rotational factors) before making chemical planning or purchasing decisions. FBN Inputs, LLC is not a licensed pest control advisor or consultant, a Certified Crop Advisor (CCA) or Certified Professional Agronomist (CPAg) and this chemical list should not be used in states where a license may be required, including, but not limited to: California, Louisiana, Maryland, Mississippi, North Carolina, Oregon, and Washington. The reader is solely and exclusively responsible for determining the suitability of any product for his/her intended use, following the product label for proper handling and use, and for complying with all applicable local, state, and federal law. This information is a summary of product information and should not be used as a replacement for consulting the applicable product label. Please consult the label for the most complete and up-to-date information about any referenced product. Readers must have a valid applicator or dealer license to use restricted use pesticides.

FBN Network

Oct 15, 2018

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