SELECTING 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)		 Large Sweet Corn With Double Eliminator A52391 40
(4.5)		 If over or under populating with starting disk, adjust double eliminator
Uniform Flat Less than 3308
(1500)		 Large Sweet Corn 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 Large Sweet Corn 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 Large Sweet Corn 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 will not perform optimally with cell-type disks. The Large Sweet Corn Disk (A52391) with double eliminator will be required for optimum seed singulation and seed release for seed sizing that is variable.

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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 seeds to plant include varieties with mixed sizes, mixed shapes, combinations of sizes and shapes, long and slender seeds, seeds with a sharp point (germ) and others.
  • Large Sweet Corn disk and Small Sweet Corn disk are two flat-seed disks which can be used for improved seed singulation with difficult to plant seeds. Sweet corn disks require higher vacuum levels than cell type disks and require the installation of a double eliminator and knockout wheel in each meter assembly.
  • Sweet corn disks have 40 holes per revolution. Set seed transmission according to population rate charts for Sweet Corn when using either Sweet Corn Disk. Overpopulating will result if cell-type corn charts are used, as those disks have 30 cells.
  • Well graded seed also requires proper seed disk selection for optimal performance.

PLANTING CORN IN HILLSIDE CONDITIONS

In hillside conditions, changing direction of planting can affect performance. Planting with the left side of the machine on the downhill can result in skips due to the seeds being pulled away from the seed disk and a smaller seed puddle next to the seed disk. With the right side of the machine downhill, overpopulation can result due to the seed being pushed against the seed disk and a larger seed puddle next to the seed disk. To maximize vacuum meter performance on hillsides, follow these steps:

  • Use the smallest seed disk possible. By using a smaller seed disk there is less opportunity for doubles.
  • Use round seed. By using round seed instead of flats, there is a better chance for seed to stay in the cell and reduced chances for doubles.
    A58156

    Overlapping Seed Disk Chart

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  • Use a flat disk with double eliminator. In some cases, round seed may not be available for the preferred seed variety or hillsides may be steep enough to require a flat type seed disk. The flat disk HAS NO SEED CELLS and requires the use of higher vacuum levels, a double eliminator and a knockout wheel. The double eliminator is used to knock off excess seed while knockout wheel is used to keep vacuum holes free of debris.
  • Set seed transmission according to population rate charts for Sweet Corn when using the Sweet Corn disk. Overpopulating will result if cell-type corn charts are used as those disks have 30 cells.

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