Use the Right Planter Plates

Many years ago the seed company DeKalb produced a handout pamphlet to help farmers determine the right corn seed plate. There is a great deal of common sense information within. We are reprinting the text and charts of that pamphlet here for your use. SFJ

3 IMPORTANT STEPS

1. USE CHARTS ON THESE PAGES as a Guide Only
2. SECURE VARIOUS PLATES EARLY
3. TEST PLATES WITH YOUR SEED
   • A – In implement dealer’s test planter, or –
   • B – In your own jacked-up planter, or –
   • C – Run planter runners up to check accuracy.

CAUTION • NOTICE

DeKalb hybrid seed is graded for correct plate sizes; however, due to such factors as speed of planting, planter wear, and adjustment, it sometimes is necessary to select plates other than those shown on the chart on the following three pages.

1. All suggestions on the chart are for an average check drop of 3 kernels per hill with the variable drop set at three; or for drilling, the plate cell accommodates one kernel. To obtain a wide range of drilling distances, plates having the same size cell but having more or less cells per plate are often required, in addition to different planter adjustments.
2. The first plate listed on the chart refers to the plate most commonly used for planting that particular grade. The second plate listed is used often when the first plate is not satisfactory.
3. Planters that travel faster than 3 miles per hour often require a larger plate than generally recommended.
4. A thicker planting on larger grades can be obtained by placing the groove of the false plate or seed-can ring next to the plate. This grooved false plate or grooved seed-can ring is standard equipment on John Deere, Blackhawk, Oliver, Case and Allis-Chalmers planters. International planters use grooved hopper bottom No. 1988A for slightly heavier planting.
5. A more uniform planting of small grades (SX-2 and SR-A and SR-B) can be made if the cut-off tongue is new or in excellent condition.

DeKalb Seed Lengths

The columns “long,” “medium” and “short” in each grade column refer to the hybrid seed having long, medium and short kernels. If there is some doubt as to what kernel length classification a hybrid belongs the longer classification is usually more desirable. Hybrids having these types of kernels are as follows:

LONG

MEDIUM

SHORT

*Listed in two different length classifications.

“Z” GRADES

The grades, SRZ-A, SRZ-B, MRZ-C, LRZ-D, SFZ-3, can usually be planted with the same plates suggested for SR-A, SR-B, MR-C, LR-D, SF-3.

These “Z” grades are separated by the DeKalb grading systems from the regular round and small flat grades to make a more uniform grade. The above “Z” grades are the slightly shorter kernels separated from the regular small flat and round grades.

The grades TFZ and LRZ-E are listed on the regular chart. The TFZ grade is a large thick flat kernel; the LRZ-E grade is a very large round kernel.

WHAT STAND TO EXPECT

Corn depends upon many natural and mechanical factors to develop. Many of these factors such as seed bed preparation, cultivation practices, insects, disease and weather can be detrimental to the average stand of corn.

The following table from Iowa corn yield trials shows the stand to expect at harvest.

CHECK YOUR PLANTER, TOO!

1. Failure of a “knocker” or ejector to work properly means kernels may be carried around in plate cells continuously, resulting in a light, irregular rate of drop.
2. Faulty fork action (improper wire clearance or tension) causes partially dropped hills, missed hills, or drops between hills.
3. Poor functioning of the clutch plate drive causes irregularity in number of kernels dropped.
4. Excessive wear, warping or inverted position of the base plate may allow improper number of kernels (1 kernel usually desired) to fall into each cell.
5. Plate driving mechanism must be timed so that seed cell is directly over runner opening at time of discharge.
6. If the cut-off tongue does not extend 1/16 inch beyond plate position it must be adjusted or replaced.
7. Faulty valve action (see inset) may result in mixed hills, carried hills, or “stringing.” Runners and valves should be kept clean and snappy in action.