Mortality assessment

Posted by Jeremy Boychyn, Agronomy Research Extension Specialist

Plenty of focus is put on 1000 kernel weights (TKW) seeding rates. Understanding your germination per cent and seedling vigor gives you an idea of how many viable seeds being seeded. However, when seeding based on TKW, per cent survival is unknown and final plant stand is therefore unknown due to factors such as soil temperature, insect feeding, moisture, and other factors.

Figure 1: Seeding rates and plant stand establishment rates adapted from Beres et al 2011 in Nobleford and Coalhurst AB. Notice decreased survivability with increased seeding rates.

The numbers above demonstrate the potential variance in per cent survival in southern Alberta (notice increased survivability with decreased seeding rates). Knowing the long-term average of crop survival helps future planning for seeding rates and plant stands. If your farm has a 75 per cent survival rate and your ideal CWRS plant stand is 250 plants m-2, you will want to seed at 330 viable seeds m-2. In crop plant stand assessments can be a useful tool.