Corn population and ear type

What effect does changing population on differing ear types have on yield?

Michigan State University Extension educators in the Thumb and Saginaw Valley regions studied three corn hybrids with differing ear types: determinant versus semi-determinant versus flex at various planting populations.

Three corn hybrids were planted. The “determinant” hybrid was Great Lakes 5245. The “semi determinant” hybrid was Great Lakes 5306. The “flex” hybrid was Great Lakes 5339. Targeted populations ranged from 29,000 seeds per acre to 38,000 seeds per acre in increments of 3,000 seeds per acre.

Results

There was a mechanical failure, and the intended 38,000 seeds per acre were actually planted at a population that resulted in 13,000 plants per acre (44.8 percent of the next lowest target population, 29,000 seeds per acre). The remaining treatments ranged from 94.2 percent of their target to 104.3 percent of their target, with an average of 98.3 percent of target.

There was no statistical difference in yield between the 29,000 and 35,000 target populations. Corn ear type also had no significant difference on yield.

There was, as would be expected, a significant decrease in yield in the misplanted 38,000/13,000 population. Note that the yield, however, on the 13,000 plant per acre population was 79 percent of the average of the greater populations.

Ear Type Target Population Actual Population Moisture (%) Test Weight Yield, Bu./A Sig
Determinant 35,000 34,750 20.4 58.6 176.8 a
Semi Determinant 35,000 34,750 21.6 58.1 176.4 a
Flex 35,000 33,000 22.2 57.9 174.6 a
Flex 32,000 32,250 22.5 57.8 171.9 a
Determinant 32,000 31,250 20.4 58.6 171.7 a
Semi Determinant 32,000 31,000 21.9 57.7 171.5 a
Semi Determinant 29,000 30,250 22.3 57.9 170.2 a
Flex 29,000 28,250 22.3 57.8 168.2 a
Determinant 29,000 27,500 20.5 58.6 167.8 a
Semi Determinant 38,000 13,000 22.2 57.9 140.6 b
Flex 38,000 13,000 21.6 58.3 136.0 b
Determinant 38,000 13,000 21.2 58.3 131.0 b
Average

21.6 58.1 163.1
LSD @ 0.05



11.5
C.V. %



7.2

Funding from the Corn Marketing Program of Michigan made this study possible. Thank you to Great Lakes Hybrids for providing seed.

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