Matching Soils to Ear Type when Selecting Hybrids
As seen in January 14th Agrinews
Apart from having productivity goals that extend beyond a single season, 365-day yield strategies to increase APH are also characterized by multiple, sometimes subtle, decisions that, collectively, expand yield potential.
As growers refine their hybrid packages for 2016, one of the understated factors worth considering involves the process of selecting ear type and leaf orientation based on soil characteristics.
Low-Productivity Acres = Flex Ear + Open-Architecture Leaf
Ground historically known for lower productivity, due to the likes of drought stress or poor organic matter, are often best served with a flex-ear hybrid that also produces an open-architecture or pendulum leaf structure.
While poised to be longer and skinnier with fewer kernel rows, flex ears have the ability to add kernel rows, girth and length, depending on the growing environment. That’s why an open-architecture leaf can provide a valuable early-season advantage, particularly in drier soils, because the open, almost flat orientation captures more sunlight and provides the shade to retain as much soil moisture as possible.
This is especially key when recommended plant populations for these types of hybrids are usually 3,000 to 5,000 off the Corn Belt’s 33,000- to 34,000-ppa average.
Variable-Soil Acres = Semi-Flex + Semi-Upright Leaf
Marrying a semi-flex ear with a semi-upright leaf orientation allows for more crowding of plants to achieve a higher population, planted in 30-inch rows or narrower, effectively creating that canopy to limit sunlight breaking through to the soil.
Hybrids with these characteristics have the ability to go across a wide variety of soil types and are ideal candidates for variable-rate seeding, because they do have that ability to flex the ear in good productivity conditions. Yet, they won’t take a yield hit when under stress or at a lower population where they can retain some of that ear size.
High-Fertility Acres = Determinant Ear + Upright Leaf
To optimize soils with a higher level of organic matter and a higher CEC content that makes more nutrients available, the obvious approach is to get as many ears on that ground as possible and support them with a more aggressive nitrogen plan.
That being the case, hybrid selection ought to lean toward a determinant ear with an upright leaf orientation conducive to populations approaching 38,000 ppa. The dense planting alleviates the need for an open, leafy canopy and the fixed ear sizing preserves valuable stock integrity and late-season intactness that can otherwise be sabotaged when a hybrid puts on more ear than it can handle under good conditions, a full growing season gets dry or the plant’s nutrient supply runs low.
Leveraging this hybrid-selection knowledge with variable-rate planting equipment—especially the latest in multi-hybrid planters—takes yield potential to an even higher level. Growers can plant, say, a flex-eared hybrid on a clay knob, lower the population and use an open-architecture leaf to harvest sunshine and minimize soil drying. Then, proceeding across the terrain, a low lying area can call for an upright-oriented hybrid that pushes populations in a semi-determinant or determinant-style ear to maximize yield.