Assessing plant establishment

Canola plant counts at around the two-leaf stage can provide an assessment of the seeding operation and identify low-count causes. In many cases, early scouting gives time to manage the cause and save the crop.

• How to count
• Common causes for low counts

Use multiple counts to get an average plant density for that field, then compare this to target plant density and emergence percentage. This will help with management decisions in that crop, and will identify areas for improvement. This short video shows how to use the Canola Calculator.

While making canola plant counts in the two weeks after emergence, also look for signs of missing plants. Read the Canola Encyclopedia chapter on evaluating the stand.

How to count
Method one: Hoop

• Quarter (0.25) square metre hoop. Use a hoop with an inside diameter of 56 cm and circumference of 177 cm which provides an area of 0.25 of a square metre. Count the number of plants inside the hoop, and multiply by 4 to get plants per square metre. To convert to plants per square foot divide the plants per square metre by 10).
• Two square foot hoop. Use a hoop with an inside diameter of 19″ and circumference of 60″, which provides an area of two square feet. Count the number of plants inside the hoop and divide by two to get plants per square foot. Counting with this larger hoop (instead of a one foot square hoop) will incorporate plants from two seed rows and give a larger sample size, helping improve accuracy of counts.
• For other sized hoops, determine the area using the formula A=πr2 (r= radius, half the diameter, π = 3.14).