Evaluating corn and soybean stands early is key to identifying problems – or potential problems – while there is still time to remedy them. Three methods are commonly used to determine stand counts:
- 1/1,000th Acre;
- Wheel; and
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The 1/1,000th Method involves counting the number of plants in a length of row equal to 1/1,000th of an acre based on row width (See Table 1). Multiply the number of plants by 1,000 to calculate the number of plants per acre. Repeat the process in several locations in the field.
The Wheel Method entails counting 150 plants and measuring the distance from start to finish with a measuring wheel. To determine plant population, divide the number of feet traveled into the appropriate factor (See Table 2).
For the Hoop Method, toss a hoop in a field and count the number of plants inside it. Repeat this in at least five locations throughout the field. Multiply the average number of plants by the appropriate factor listed in Table 3 to calculate the number of plants per acre. NOTE: Having a hoop with a diameter of 28 ¼” allows you to simply multiply by 10,000 to determine the number of plants per acre. You can make a hoop this size by cutting anhydrous tubing to 88 ¾ inches and joining it to form a circle.
Source: Monsanto’s Agronomic Spotlight, 4/26/10, Illinois Agronomy Handbook. 23rd Edition. Pg. 31. Purdue Corn & Soybean Field Guide. 2007.