Variable-Rate Seeding Effect on BMR Silage Yield


  • Determine the effect of variable-rate seeding prescriptions on Brown MidRib (BMR) silage yield.

Study Description

Study Locations:   3 fields in central New York

Map: Research Location

Pioneer® brand BMR hybrid:   P1449XR (HXX,LL,RR2)
Populations (plants/acre): 30,000      33,000      36,000
Management Zones: High, medium, and low based on 3 years of multi-year yield analysis (MYYA).

Map: VRS study fields

Figure 1. Management zone and check block configuration of 1 of the VRS study fields in 2014.

  • 4 years of silage yield data were used to create 3 management zones (Figure 1):
    • High yield (> 110% average yield)
    • Average yield (90-110% of average yield)
    • Low yield (< 90% of average yield)
  • Variable-rate seeding prescriptions were written for the 3 study fields with a population of 36,000 plants/acre assigned to high-yield management zones, 33,000 plants/acre to average yield zones, and 30,000 plants/acre to low yield zones.
  • Half-acre check blocks of each population were established in each management zone for comparison against each other and validation of the prescription. (Figure 1)

Data Collection

  • As-planted data were collected from the planting monitor for management zones as well as check strips to evaluate infield plant population accuracy. (Figure 2)
  • Machine transitions between populations were estimated to require 30 feet of travel distance.
  • Silage yield data from a John Deere 2630 monitor equipped with John Deere HarvestLab™ were collected at harvest.
  • Treatment analysis was performed within each management zone to determine the yield of each check block within the zone (Figure 3).

Map showing as-planted data for VRS study field.

Figure 2. Map showing as-planted data for 1 of the VRS study fields in 2014; Red: 30,000 plants/acre, Yellow: 33,000 plants/acre, Green: 36,000 plants/acre

Map showing silage yield for VRS study field.

Figure 3. Silage yield (tons/acre at 35% dry matter) reported via treatment analysis for 1 of the VRS study fields in 2014.



Table 1. Average silage yield reported as tons/acre at
35% dry matter in high, average, and low yield
management zones across 3 study fields in 2014.
   (1,000 plants/acre)    
   Management Zone Yield Level   
 High   Medium   Low 
  —— silage yield (tons/acre) ——
 30  29.6 29.1 21.0
 33  31.8 30.8 23.5
 36  31.8 29.2 25.6


  • Results indicate that variable-rate seeding did not provide a silage yield benefit in the study fields and that the best management strategy likely would have been to plant the entire fields at a fixed population of 36,000 plants/acre, rather than using a variable-rate seeding prescription.
  • Previous research studies showed that Pioneer® hybrid P1449XR yield was maximized at approximately 36,000 plants/acre.
  • A possible limitation to this study is that the parameters used for building the MYYA management zones may have been too narrow to take into account the varying yield potential in parts of these fields.
    • This could have resulted in placing lower population in areas of the field that may not have benefitted from fewer plants per acre.
  • Optimal populations may not have been realized since the highest yields were achieved at the highest seeding rate.

2014 data are based on average of all comparisons made at three locations through 11/12/14. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product responses are variable and subject to a variety of environmental, disease, and pest pressures. Individual results may vary.

All products are trademarks of their manufacturers.

  HXX - Herculex® XTRA contains both the Herculex I and Herculex RW genes.
Herculex® XTRA Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred. Herculex® and the HX logo are registered trademarks of Dow AgroSciences LLC.
  LL - Contains the LibertyLink® gene for resistance to Liberty® herbicide.
Liberty®, LibertyLink® and the Water Droplet Design are trademarks of Bayer.
  RR2 - Contains the Roundup Ready® Corn 2 trait that provides safety for over-the-top applications of labeled glyphosate herbicides when applied to label directions.
Roundup Ready® is a registered trademark used under license from Monsanto Company.

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