EXAM – Canola Watch 2025 – Section 4

1. Reynald Lemke led a study on nitrous oxide emissions from fields during the winter. In the study summary, Lemke notes that N₂O emissions during denitrification is invariably accompanied by an even larger, often as much as ____ times larger, production of di-nitrogen (N₂) gas. (Fill in the blank.)

2. Breanne Tidemann led a study on fall emergence of cleavers. Tidemann tested 25 different cleavers populations for emergence characteristics. She also tested efficacy of a specific herbicide, concluding that a number of cleavers populations showed “limited control”. What was the herbicide?

3. Charles Geddes studied the critical period for weed seed control (CPWSC) for seven common weeds. Early removal of weed competition is essential to maximize crop yield potential. But the critical window is different to limit weed seed set. Based on the Geddes study results, what is the average CPWSC for wild oat?

4. Charles Geddes had another study to establish an economic threshold for glyphosate-resistant kochia in canola fields. Based on results from this study, the economic threshold to control kochia in canola is _______ kochia plants per square metre.

5. Boyd Mori looked at insect tolerance to seed treatments. The project concluded that__________ seems to tolerate the neonicotinoid seed treatments. (Fill in the blank)

6. Derek Peak led a study to test Fourier Transform Near Infrared (FT-NIR) for its ability to provide quick and reliable soil analysis. Only two characteristics were reliably predicted. Total soil nitrogen was one. What was the other?

7. Hector Carcamo studied peristenus wasps, and discovered one native species finally starting to make a difference to lygus bugs populations. Parasitism of lygus by the P. howardi wasp had been near zero in previous surveys of canola. In Alberta surveys from 2021 to 2024, what percentage of lygus nymphs were parasitized by these native wasps?

8. Tim Dumonceaux led a study to identify and test soil-derived bacteria for their ability to suppress disease. One specific strain, coded PENSV20, shows potential as a biocontrol agent to suppress which canola disease?

9. Tyler Wist led a study to find out where aster leafhoppers take up the aster yellows phytoplasma (which they subsequently spread to canola and other crops). According to study results, aster leafhoppers most often pick up the pathogen while feeding on _________. (Fill in the blank.)

10. Water increases productivity. Alberta Canola, in it’s bulletin in Canola Digest Science 2025, noted that while irrigated acres represent only 4.4 per cent of Alberta’s cultivated land, they generate __ per cent of the province’s total agri-food GDP. (Fill in the blank.)