Multi-Hybrid Planting Trials in Southwestern Iowa
- The technology to vary hybrid placement across a field is now available to corn growers, making the potential value of this technology for improving yields an important consideration.
- Field-scale on-farm trials were conducted in 2015 to explore the potential value of variable hybrid placement.
- Eight field-scale trials were conducted in southwestern Iowa in 2015. Field size ranged from 56 to 199 acres.
- The trials were planted using a Kinze 4900 multi-hybrid planter.
- Management zones for the fields were delineated based on soil types.
- A hypothetical multi-hybrid prescription was created for each field by assigning one of the two hybrids to each management zone based on which hybrid was expected to be the higher-yielding of the two.
- In the actual prescription that was planted, blocks of both hybrids were placed within each management zone; allowing the ability to compare yield of the hybrid assigned in the multi-hybrid prescription and the alternate hybrid.
- Two corn products were selected for each field based on local recommendations; designated as a “defensive” product and “offensive” product and assigned to low and high productivity management zones, respectively.
- A total of four Pioneer® brand corn products were used across the eight trials (Table 1 and Table 2).
Table 1. Pioneer® brand corn products used in 2015 on-farm multi-hybrid planting trials.
²Drought tolerance is a complex trait, determined by a platform's ability to maintain yield in limited-moisture environments. A higher score indicates the potential for higher yields vs. other platforms of similar maturity in limited-moisture environments.
Table 2. Corn product designations for each multi-hybrid planting trial location in DuPont Pioneer on-farm trials.
- Results showed that, at all eight trial locations, the best outcome would have been achieved by planting one hybrid across the entire field (Table 3). In most cases this was the offensive hybrid.
- At five of the eight locations, the offensive hybrid was the best yielding across all management zones.
- At the two locations where Pioneer® P1197AM™ brand corn was designated as the defensive hybrid, it was higher yielding than the offensive hybrid.
- The predicted whole-field average yield for the multi-hybrid prescription was usually intermediate between the predicted whole-field average yields for the two individual hybrids.
- Yield for multi-hybrid planting was 10.8 bu/acre less on average than if the whole field had been planted to the higher yielding hybrid.
Table 3. Predicted whole-field average yield in DuPont Pioneer on-farm trials for both individual hybrids and the multi-hybrid prescription, and the difference between multi-hybrid and the better of the two hybrids.
- At the three locations where the defensive hybrid had greater yield in portions of the field, the potential benefit of multi-hybrid planting was limited in part by imperfect hybrid placement; i.e., there was not perfect alignment between the zones where the defensive hybrid was assigned and zones where it actually performed better.
- Had hybrid placement been optimal in these three locations, multi-hybrid planting would have resulted in a whole field average yield between 0.6 and 2.6 bu/acre better than planting the entire field to the best of the two hybrids (Table 4).
- Lost yield potential due to imperfect hybrid placement at these locations ranged from 2.6 to 8.7 bu/acre.
Table 4. Potential yield advantage with multi-hybrid planting at select locations if hybrid placement had been optimal.
- The outcome of the multi-hybrid trials in 2015 was largely driven by the weather conditions experienced during the growing season.
- Moisture was generally ample, in some cases excessive, in the study area in 2015, which minimized the number and extent of environments in which a more drought tolerant hybrid would provide a yield advantage.
- Given that these trials were all conducted in one growing season under similar conditions, the results do not provide much insight on the potential value of multi-hybrid planting across a wider diversity of environments.
- However, they do provide a very good illustration of a set of conditions under which multi-hybrid planting is unlikely to provide value and could, in fact, carry significant downside risk.
- Continued on-farm experimentation across a wider range of environments will help direct multi-hybrid technology to the places where it will provide the greatest benefit.