This table can be used for all crops to determine plant population or seed drop per acre. Simply follow these easy steps.
(1) Find average row width, in inches (top line).
(2) Either Determine average spacing between seed (or plants), in inches, (left column)
OR Determine average number of seeds (or plants) per 50-foot row length (right column).
(3) Read seed drop (or plants) per acre from table (intersection of line and column).
Example (Seed Drop): You want to drop 29,000 corn kernels per acre and are using 36-inch rows. Find “36” in the top line, read down to “29”, read across to “6” in the left column. Seeds should be spaced 6 inches apart.
Example (Seed Drop): In checking behind your drill with 15-inch row spacing, you determine that the seeds average 3 inches apart. Read down the left column to “3”, read across in the “15” column, where the column and line intersect read “139”. You are planting approximately 139,000 seeds per acre.
Example (Plant Population): You make several stand counts and calculate an average of 55 plants per 50 feet of row. The rows are 30 inches apart. Read down the right column to “55”, read across to the “30” column, where the column and line intersect read “19”. The plant population is approximately 19,000 per acre.
For other situations not shown, use these formulas:
*Plants or seed/acre (thousands) = (number seeds or plants/50-foot row x 10.45) ÷ row width (inches)
*Plants or seed/acre (thousands) = (6,273 ÷ row width [inches]) ÷ average kernel spacing (inches)
** Seed or plants/50-foot row = seeding rate/acre ÷ (10.45 ÷ row width [inches])
***Avg. kernel spacing (inches) = (6,273 ÷ row width [inches]) ÷ plants or seed/acre