SELECT THE CORRECT FIELD CORN SEED DISK FOR OPTIMUM PERFORMANCE

Corn Seed Disk Selection Guide
Seed Shape Seed/kg
(Seed/lb)		 Disk Name Part Number Number of Cells
(Hole Diameter (mm))		 If population is hard to control
Non-Uniform (mixed shapes) Mixed Sizes
(Mixed Sizes)		 ProMax 40 With Double Eliminator A52391 40
(4.5)		 If over or under populating with starting disk, adjust double eliminator
Uniform Flat Less than 3308
(1500)		 ProMax 40 With Double Eliminator A52391 40
(4.5)		 If over or under populating with starting disk, adjust double eliminator
Uniform Flat 3308-6175
(1500-2800)		 Small Corn Disk A43215 30
(3.6)		 Adjust vacuum first, if unsuccessful, switch to overlapping disk shown in vacuum level charta
Uniform Flat Greater than 6175
(2800)		 Sunflower/
Popcorn		 H136478 30
(2.6)		 Adjust vacuum first, if unsuccessful, switch to Small Corn Disk (A43215)
Uniform Round Less than 3308
(1500)		 Standard Corn Disk A52391 30
(3.6)		 Adjust vacuum
Uniform Round 3308-6175
(1500-2800)		 Small Corn Disk A43215 30
(3.6)		 Adjust vacuum first. if unsuccessful, switch to Standard Corn Disk (A50617)
Uniform Round Greater than 6175
(2800)		 Sunflower/
Popcorn		 H136478 30
(2.6)		 Adjust vacuum first, if unsuccessful, switch to Small Corn Disk (A43215)
aFor larger seed sizes that are less than 3970 seeds/kg (1800 seeds/lb), switch to Standard Corn Disk (A50617). If population control problems persists, switch to ProMax 40 Disk (A52391) with double eliminator. For smaller seed sizes that are greater than 5072 seeds/kg (2300 seeds/lb), switch to Sunflower/Popcorn Disk (H136478). If population control problem persists, switch to ProMax 40 Disk (A52391) with double eliminator.

 

Use the above Corn Seed Disk Selection Guide to determine the recommended seed disk first, and then refer to vacuum level chart for initial vacuum setting.

Most corn seed can be planted near 100 percent of desired population when using small corn or standard corn seed disks (WHICH HAVE SEED CELLS) and properly adjusted vacuum level.

Using cell-type disks (Small and Standard Corn Seed Disks) requires careful selection for proper performance.

Metering performance is directly dependent on the consistency of seed sizing. Seeds that are mixed in shape and size do not perform optimally with cell-type disks. The ProMax 40 Disk (A52391) with double eliminator is required for optimum seed singulation and seed release when seeds vary in size.

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NOTE: A knockout wheel is required when using John Deere Flat Disks.

For seed sizes that overlap the Small Corn Disk (A43215) and the Standard Corn Disk (A50617), choose the Small Corn Disk for initial setting. If population is difficult to control, switch to Standard Corn Disk.

DIFFICULT TO PLANT SEEDS

  • Difficult to plant seeds include varieties with mixed sizes, mixed shapes, combinations of sizes and shapes, long and slender seeds, seeds with a sharp point (germ), and others.
  • A ProMax 40 disk is a flat disk used to improved seed singulation with difficult to plant seeds. The ProMax 40 requires higher vacuum levels than cell type disks and requires the installation of a double eliminator and knockout wheel in each meter assembly.
  • ProMax 40 disks have 40 holes per revolution. Set seed transmission according to Corn Using ProMax 40 Disk rate chart when ProMax 40 disk is used to plant field corn. Overpopulation occurs if cell type rate charts are used with a ProMax 40 disk. Cell type disks have 30 cells.
  • Well graded seed also requires proper seed disk selection for optimal performance.

PLANTING CORN IN HILLSIDE CONDITIONS

The angle of a hillside or changing directions on a hillside has the potential to affect meter performance. If the left side of machine is the downhill side, skips are possible due to the seeds falling away from the seed disk and a smaller seed reservoir next to the seed disk. If the right side of machine is the downhill side, overpopulation is possible due to the seeds forced against the seed disk and a large seed reservoir next to the seed disk. To maximize vacuum meter performance on hillsides, follow these steps:

  • Use a disk with the fewest holes possible. Fewer holes provides less opportunity for doubles.
  • Use round seed. Round seed remains in the cell of a cell type disk better and reduces the chance for doubles.
    A58156

    Overlapping Seed Disk Chart

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    IMPORTANT: Set seed transmission according to Corn Using ProMax 40 Disk rate chart when ProMax 40 disk is used to plant field corn. Overpopulation occurs if cell type rate charts are used with a ProMax 40 disk. Cell type disks have 30 cells.

  • Use a flat disk with double eliminator, if round seed is not available or hillsides are very steep. The flat disk HAS NO SEED CELLS and requires higher vacuum levels, a double eliminator, and a knockout wheel. The double eliminator is used to remove one of two seeds covering a single hole in seed disk. The knockout wheel is used to remove debris from holes in seed disk.

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