In choosing a corn hybrid and planting population for any piece of ground, there are some basic pieces of information needed to match one of the hundreds of hybrids available from multiple companies to the specific situation where the hybrid will be placed. Key pieces of information include:
- Yield Goal
- Maturity of Field
- Water Management for the Field
- Soil Type / Characteristics
- Field History
- Other
Let’s take each piece of information and see how to use it to determine a hybrid selection for a field (or part of a field).
Yield Goal
Establishing a yield goal is the first step. Historical performance is a good way to evaluate the level of expected future performance. Review several growing seasons to include some dry years and some wet years. A 3-5 year average works well and then include a 10% increase realizing management will need to match.
Maturity of the Field
Each hybrid has a known number of growing degree days required for its maturity. Knowing the typical growing degree days of the area to be planted helps to match the two so that the corn can reach its maximum potential. If you pick a short season corn hybrid (such as a 100-105 day corn), you may leave bushels on the table because we’re not taking advantage of the entire growing season. On the other hand, planting a hybrid that is too long of a corn hybrid (120 day) could result in incurring additional drying costs because the corn did not have time to mature in the field – or worse, an early frost cut it off prematurely with the result of lower yields and poor grain quality.
There may be a reason to choose a corn hybrid maturity other than what specifically fits a field. For instance, if the corn were going to be harvested for silage or wet corn, we may choose a product that has a longer maturing season than typically would be grown here because we know we can handle a higher harvest moisture. If we have a lot of acres to harvest, we may use a shorter season product so that it matures early and we’re able to get harvest started.
Water Management for Field
In western Nebraska, we commonly deal with several types of water management. Dryland (or rainfed) fields have a lower yield potential than those that have limited or full irrigation. Some hybrids are very good choices for dryland but may not have the upside potential if the field receives abundant rainfall. It is critical that we look for hybrids that will be able to handle some level of stress as we will usually experience hot and dry conditions during the growing season. Limited irrigation would result from having a short well or perhaps in areas with water allocations. Matching the hybrid to the level of irrigation is critical in western Nebraska.
Also keep in mind that plant population can be used to mitigate the level of water stress for a crop. Many dryland fields may have populations between 12-18K because the soil water is limited, however, fewer plants take up less water. On the other hand, a fully irrigated field with a good water holding capacity may be 32-38K. Knowing field history and soil types within a field can be important, especially if you have the ability to change populations (or even hybrids) with the same field.
Soil Type/Characteristics
In addition to water holding capacity, knowing the pH of a field is critical to placing the right hybrid; some simply perform better than others under high pH conditions.
Fertility
Hybrids respond differently to varying levels of fertility, especially nitrogen. Many high yielding hybrids require a very high level of N for the season. This can be a critical decision as well. If you’ve noted early lower leaf senescence or severe tip back in previous years, you may be leaving your crop short of nutrients. On the other hand, healthy canopy late in the season and ears filled to the tip may indicate your fertility program may be reaching a level that is economically detrimental. Having a little tip back at the end of the season means you really hit the sweet spot for the fertility of that field.
Pick a hybrid that matches your field history and your plans for fertility for a particular field.
Rotational History
Many pests (especially insects and diseases) thrive in continuous corn. Picking the right trait will help address insect issues like western corn rootworm in continuous corn while planting in a corn/soybean rotation will give some flexibility for this pest.
Disease pressure from previous crops can be addressed with hybrid selection, as well. Goss’s wilt, corn lethal necrosis (CLN) and others cannot be addressed with fungicides, so hybrid selection is critical in areas of known issues.
Summary
In addition to knowing some of these critical pieces of information about a field and the characteristics of a hybrid, it’s also good to look at past performance of several hybrids across years with different environments and planting populations. Using this historical yield data from different hybrids at different planting populations helps to “pressure test” a product to know it has worked well under similar circumstances in the past.
Most of this information is available from the various independent agronomists in our area or a trusted seed agronomist from one of the many seed companies that service our area. Build a relationship with these industry folks as they can be a true asset for your operation.
Randy Lloyd
randy.lloyd@unl.edu
Research Facility Coordinator
West Central Research, Extension and Education Center
University of Nebraska-Lincoln
