Manage corn planting decisions to optimize yield and economic return
With increasing costs for corn production and fluctuating grain prices, it is critical that corn growers make sound decisions about planting and the use of purchased inputs. From 2009 to 2011, research was conducted in southern and central Minnesota to evaluate corn response to plant population, and whether this is affected by planting date, hybrid maturity, and row width.
Figure 1. Corn response to row width and plant population at
Lamberton and Waseca, MN from 2009 to 2010. Each dot is
the average of 3 hybrids.
Figure 2. Corn response to hybrid maturity and plant population at
Lamberton, Morris, Rochester, and Waseca, MN from 2009 to 2010.
Figure 3. Corn response to planting date and plant population at
Lamberton, Morris, and Waseca, MN from 2009 to 2010.
- Corn response to plant population was not affected by row width or hybrid relative maturity (RM) (Figures 1 and 2). However, when corn planting was delayed until late May, a higher final plant population was needed to maximize yield (Figure 3).
- Across all trials, yield was maximized with a final stand near 33,000 plants/acre, and was not reduced as plant population increased to 44,000 plants/acre (Figure 4).
- Narrow rows did not increase corn yield (Figure 1), but yield was greater with mid- and late-maturity hybrids than early-maturity hybrids (Figure 2). The early-, mid-, and late-maturity hybrids evaluated in this study were 95-, 101-, and 105-day RM in southern Minnesota, and 91-, 94- and 99-day RM in west-central Minnesota.
- There was little yield reduction when planting was delayed until mid-May, but yield dropped off quickly as planting was delayed beyond mid-May (Figures 3 and 5). However, yield reductions due to delayed planting in these trials were less than expected.
Table 1. Corn response to plant
population, based on Figure 4.
Table 2. Seeding rates (seeds/acre) to get within $1.00/acre of maximum net return, based on Figure 4. Seeding rates are 5% above targeting final population to account for early season stand losses.
|Seed cost||Corn price ($/bushel)|
|225||30,700 – 33,700||32,100 – 34,400||32,700 – 34,700|
|275||30,100 – 32,900||31,700 – 34,000||32,400 – 34,400|
|325||29,400 – 32,300||31,200 – 33,500||32,100 – 34,100|