One bertha armyworm per square metre can reduce canola yield by 0.058 bu./ac. So, 17 of them per square metre will drop yields by around 1 bu./ac. This information helps growers assess the threat and spray only when numbers are sufficient to provide a return on investment. How do we know these thresholds? Research.
Canola Performance Trials (CPTs) for 2017 included straight cut trials, more clubroot-resistant varieties and extra detail on environment and management for each trial site. Find the latest data at canolaperformancetrials.ca
CPT: An excellent tool for the grower toolbox
The Canola Performance Trials website provides third-party variety comparison data from small and large plots, with useful tools to customize searches, compare varieties head to head and look beyond yield results.