This Pioneer Crop Insights highlights the importance of planting practices on final stand and yield. This are the factors we can control as we head to the field to maximize our production the entire growing season.
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Summary
Uniformity of plant emergence, planting timing, plant population, and evenness of plant spacing are 4 outcomes of planting that can influence final corn yield.
Research has shown that delayed emergence can reduce the yield of individual plants in a stand; however, the notion that a plant emerging more than 48 hours after its neighbors is a “weed” is clearly not supported.
Corn yield potential declines as planting is delayed beyond the optimum planting window for a given geography, and the yield penalty tends to be greater in northern areas where the growing season is shorter.
Optimum plant population can be influenced by factors such as yield level, hybrid, and weather conditions.
The CoV and singulation readings on the planter monitor are valuable real-time indicators of meter performance but poor predictors of the agronomic consequences of common, realistic non-ideal planting outcomes.
Within-row plant spacing uniformity does impact grain yield; however, whole-field impacts on grain yield are usually relatively small, averaging about 1% to 2%.
By far, a skip is the planting outcome that contributes the most to yield loss, whereas occasional doubles have no negative impact.
4 Planting Outcomes for Success
Planning and execution associated with corn planting are critical if growers are to maximize the genetic potential of today's elite corn hybrids. The simple secret for success is to "do everything right." Many of these key management decisions are made well before the planting season, including choice of hybrid, crop rotation, tillage system, nutrient placement, target planting rate, and row spacing.
This Crop Insights focuses on the 4 planting outcomes that are achieved during planting itself. The relative impacts these 4 factors have on grain yield were recently summarized by Dr. Jeff Coulter from the University of Minnesota4 and are presented below.
These goals and their estimated typical impact on yield include:
Achieve uniform emergence (5-9%)
Plant within the optimum window (2-5%)
Achieve the correct population (1-2%)
Achieve uniform plant spacing (1-2%)
The latest research related to achieving each of these 4 planting outcomes is discussed and, in several cases, suggest the need to rethink conventional wisdom regarding their importance in affecting grain yield.
1. Achieve Uniform Plant Emergence
A primary goal of corn growers is to achieve stands containing uniformly large-sized plants that consistently produce 1 full-sized ear each. Small, delayed or "runt" plants rarely, if ever, produce full-sized ears. Traditionally, growers have assumed that the primary cause of these smaller, undesirable plants was a delay in the time of emergence. And often the cause for delayed emergence was assumed to be inconsistent seeding depth. Logically, late-emerging plants are less able to compete for limited light, nutrient, and moisture resources with earlier-emerging and larger neighbors. Several studies have indeed documented significant yield loss when the development of plants within the stand was delayed (Nafziger et al., 1991; Ford and Hicks, 1992; Liu et al., 2004a, 2004c). These studies typically used multiple planting dates 7 to 28 days apart to achieve varying degrees of delayed plant growth. These studies are ...."