Canola Watch 2013 Exam

CCA Quiz 2013 answer key

NOTE: This is the 2013 exam!!

This exam period ended January 31. Feel free to use this quiz as a refresher.

Successful completion of the exam was worth 6.5 CCA credits, as follows:
Nutrient Management: 1
Soil & Water Management: 1
Integrated Pest Management: 3
Crop Management: 1.5

CCSCs also qualified for 6.5 credits.

All answers can be found in the 2013 Canola Watch reports, which are in the Archives section at

For questions or additional information on this exam, please contact Jay Whetter at 807-468-4006 or


1. The March and April issues of Canola Watch featured highlights from CanoLABs held in Brandon, Saskatoon and Edmonton. The next 10 questions are based on CanoLAB presentations.
Based on the numbers John Heard from MAFRI used in his presentation, how much nitrogen (N) and how much sulphur (S) are required to produce one bushel of canola?
2. Canola plants need ______ to produce three key amino acids: methionine, cysteine and cystine. Without ______ to build these amino acids, nitrogen can create toxic amides in the plant that greatly inhibit seed set.
3. Phosphorus deficiency is not always easy to detect visually, but without applying replacement rates, canola yield potential will drop over time. What does Jeff Schoenau from the University of Saskatchewan call this phosphorus deficiency?
4. Plants with _______ deficiency will often flower longer to compensate for poor seed set, and have leaf blotches ranging from pale yellow to reddish purple. This nutrient deficiency is more likely to show up in sandy areas.
5. Presenters at CanoLAB in Brandon said herbicide carryover in the soil in spring 2013 could be higher than expected because of what specific condition?

6. Aster yellows is caused by a phytoplasma carried by the aster leafhopper (shown here). Most aster leafhoppers come into the Prairies on winds blowing in from what area?

The aster leafhopper (species Macrosteles quadrilineatus) has 4 distinct black lines on its head. You can see these lines with a magnifying glass.
7. Hot days (28°C and higher) can cause canola flowers to abort. The combination of hot days and __________ can be particularly devastating.
8. Glyphosate applied after ________ on Roundup Ready canola may result in pale petals of normal size and short stamens that don’t protrude above petals in recently opened flowers. There can be significant pod sterility and blanks as a result.
9. A critical time to control kochia is in the pre-seed window as _______ of kochia seedlings emerge before the crop.
10. Clubroot resistant varieties are an effective tool for clubroot management. However, __________ will select for those clubroot pathotypes that are not controlled by the genetic resistance, ending the effectiveness of resistant varieties on those fields.


11. The following 40 questions are from the articles in Canola Watch from May to October.Effective pre-seed glyphosate depends on strong biological activity within the target weeds. Warm weather helps. The ideal temperatures for glyphosate efficacy are at least ________ for daytime highs and a minimum of _______ at night.
12. Saskatchewan weed specialist Clark Brenzil names two weeds that are not household names but are on the rise. What are they?
13. University of Manitoba soil scientist Don Flaten says to place only ammonium phosphate in the canola seed row, and even then, only use a “modest” rate. What is generally considered the maximum safe rate of actual phosphate to put in the seed row?
14. Agronomists are encouraged to follow their own best management practices when it comes to clubroot. The top two clubroot BMPs for agronomists entering canola fields are:
15. Scouting is something growers can do all season long. How long after seeding does Canola Watch recommend canola crop scouting start?
16. Spraying weeds early in crop can improve yields with no added cost, thus having a significant influence on profit. Research has demonstrated an advantage of _____ for controlling weeds at the 1-2 leaf stage of canola versus the 6-7 leaf stage.
17. The economic threshold for flea beetles is based on a stand of ________ plants per square foot. In thinner stands, growers may want to reduce the threshold somewhat to limit plant loss and development delays.

18. When top dressing liquid fertilizer, the ideal is to apply when leaves are moist from early dew or a light rain. Why?
19. When tank mixing clethodim with Liberty, the order in which you add each component to the tank is important. What is the order?
20. In the tutorial video called “How to use the Canola Diagnostic Tool,” what is the disease highlighted in the example?

21. Most cutworm larvae feed on above ground foliage. Only two common species, as outlined in the table showing lifecycles of cutworm species, are underground or “subterranean” feeders. Which one of the following cutworms is an underground feeder?
22. Growers on the fence about whether to apply a fertilizer top-dress are encouraged to apply enough to make a noticeable difference, and then test the result. Apply the top dress to part of the field, mark the location, and compare yields between treated and untreated sections at harvest. What does Canola Watch suggest is an amount of nitrogen sufficient to make a difference?
23. Spraying glyphosate after the 6-leaf stage or at higher than label rates on Roundup Ready canola can set back yield. Monsanto research demonstrated a ____ bu./ac. yield loss as a result of spraying glyphosate on Roundup Ready canola at higher than labeled rates and at first flower.
24. The following sentence describes which seedling disease pathogen? This pathogen attacks the hypocotyl and tends to be worse when canola emergence is delayed due to cool, dry conditions.
25. Canola can recover from early season hail. Even in severe cases that cause individual seedlings to die, a whole canola crop is fairly resilient to early season hail when it comes to overall yield potential. An average stand can be reduced to fewer than ___ plants per square metre before yield losses exceed 10%.

26. Aerial herbicide application is an option if the application window is closing and the ground is too soft for a ground rig. One downside to aerial application is that buffer zone requirements are significantly higher for air versus ground application. For Liberty, for example, the buffer zone for aerial application is ___ from non-target plants and animals compared to a buffer of only ___ for ground application
27. When scouting for cutworms, you are more likely to find them by:
28. In Canada, 80% of the honey comes from canola flowers. And although napus canola is self-pollinating, studies show that the extra level of pollination that bees and other pollinators provide can increase yields by up to ____.
29. To protect bees and other pollinators, do not spray insecticides on a crop in flower. If spraying a crop in flower is necessary, when is the best time to spray in order to avoid contact with bees?
30. The best way to manage clubroot is to identify the disease early and stick to management steps that are known to be effective. Only one of the following is an effective management step. The others are not practical or effective. Which is it?

31. The nominal threshold for diamondback moth larvae is 20 to 30 per square foot of crop, or about two or three larvae per plant if plant population is close to 10 per square foot. The key is timing. At what stage are diamondback moth larvae most damaging, which is the stage when control is most likely to pay off?
32. Cabbage seedpod weevils overwinter as adults in field margins. However, early spring spraying is not recommended because the goal with a spray is to ________________.
33. The nominal threshold for cabbage seedpod weevil is 20 adults per 10 sweeps. If counts are above threshold, the best time to spray is __________________.

34. Canola Watch quoted Lloyd Dosdall, an entomologist with the University of Alberta, talking about results from a rotation study. Dosdall said, “The data show very clearly that with continuous canola, there is a statistically significant increase in crop damage by ________ , and this coincides with reduced yields.” What insect is he talking about?
35. The nominal threshold for grasshoppers is 8-12 per square metre. If grasshoppers require spraying, warm days are better than hot days for insecticide efficacy on grasshoppers. Why?
36. One way to estimate whether a canola crop is at 50% flower is to count the number of open flowers (which includes aborted flowers and developing pods). How many open flowers on the main stem is generally considered to coincide with 50% flower?
37. Each crop protection product has its own pre-harvest interval (PHI) for canola. When spraying, it is important to adhere to the PHI to ensure that no unacceptable levels of chemical residue will be found in harvested seed. What is the PHI?
38. The ideal swath timing is when 60% of seeds on the main stem are showing colour change. Colour change is considered ___________?

39. An article on tips to lower straight combining risk noted that planning to straight combine starts at seeding. What are three seeding time decisions that can help reduce losses in a straight-combined canola crop?

40. When measuring canola losses out the back of the combine, calculating the concentration factor will provide a more accurate assessment of loss. What is the concentration factor?
41. By taking harvest plant counts over a number of fields and years, canola growers can get a clear idea how plant count influences yield. This information can help them set seeding rates. Counting plants again at harvest is important to this calculation because the number of plants per square foot often drops by _________ between post emergence and harvest.

42. Canola needs some time cure between swathing and combining, but curing doesn’t have to be a specific length of time. As long as _________________, growers are encouraged to start combining.

43. Canola that has dried down but still has a high green count will need its seed moisture levels to get back above _______ with temperatures remaining at 15°C or warmer for chlorophyll-clearing enzymes to restart and produce significant curing. Several days of heavy dew, high humidity and additional rain events may be required.
44. Cleavers seem to be getting worse in some fields, and can be a particular problem for canola grading. Cleaver seeds in a canola sample are graded as “conspicuous admixture.” The limit for total conspicuous admixture for No.1 canola is ___________.

45. Fall is a good time to take soil samples. Fall samples can provide a close approximation of soil nutrient levels in the spring as long as fall samples are taken when soil temperatures have cooled to below _____.
46. One type of soil sampling method involves separating a field into distinct management units based on soil type, topography, and/or yield map history. Management units are sampled separately, resulting in 3 to 5 soil samples from the field. What is this sampling method called?
47. ________________________ are often seed placed with canola, and yet growers cannot usually safely apply seed-placed rates that are high enough to meet the nutrient needs of canola. One solution is to apply these two nutrients during the cereal part of the rotation. This will maintain baseline levels so seed-placed rates for canola can stay within safe levels the next time canola is produced on that field.
48. A risk with fall application of nitrogen fertilizer is that denitrification and leaching will remove a large percentage of the applied fertilizer before seeding starts in the spring. The best soils for fall banding, in terms of lower risk for losses, are ________________________.
49. Growers who apply elemental sulphur in fall are encouraged to continue this practice on a regular basis as part of their sulphur fertilizer program. Why?
50. Sulphur deficiencies are possible in any region, especially on fields with frequent canola rotations, but _________________ tend to be the most responsive to sulphur fertilizer.

Insect management thresholds

51. In February 2013, Canola Watch ran a comprehensive article on insect management thresholds. The next five questions are from that article.Insect management thresholds provide an approximate estimate of what?
52. Most thresholds used to manage insects in canola are “nominal” thresholds. Experienced entomologists set nominal thresholds based on practical experience. Only two canola pests have thresholds based on peer-reviewed research. What are they?
53. Lygus thresholds are based on sweep net counts. If canola is $12 per bushel and spray is $8 per acre, the threshold at the late pod stage is ____ lygus per 10 sweeps.
54. Proper sweep netting technique is required in order for lygus thresholds to be effective. What is a key component of proper sweep net technique?
55. Thresholds are only one factor in the spray decision. Even if numbers are above the thresholds, spraying may not provide a return on investment if?

Quiz review

56. Every week during the growing season, Canola Watch featured a photo quiz. The following 10 questions are based on those photos. You will often need to take the quiz to find the answer, which is given at the end of each quiz.These rows of canola plants are planted into soil from the same field. The dark soil is from a rich low-lying area. The light soil is from an eroded knoll with low organic matter. Each row has a different treatment, with row 1 (farthest to the left) the control. Treatments in the rich soil look about the same, while treatments on the eroded knolls get worst as you move to the right. What are the test treatments that caused these effects?

57. A grower applied a pre-seed burnoff to a field in southwest Saskatchewan. A week later, he checked the field and found these healthy weeds in a line in one corner of the field. What is this weed?

Quiz 2
58. Both of the young canola plants in this photo are pinched along the stem. What caused the pinch on the left, and what caused the pinch on the right?

Quiz June 5
59. Here are two views of the same insect. What is it?

June 19 quiz
60. What caused this damage?

July 10 quiz
61. Some diseases look alike. What caused the lesions on these two canola leaves?

July 31 Quiz
62. Swathing is a good time to look for diseases. Sometimes you can identify a disease from the stem damage. What diseases, from left to right, caused the stems to look like this?

August 28 quiz
63. This worm prefers to eat cleavers. What is it?

September 5 quiz
64. What has infected this pod?

Quiz September 18
65. What is this weed?

Quiz September 25

Sclerotinia stem rot

66. In January 2013, Canola Watch ran a comprehensive article on Sclerotinia stem rot management. The first five questions are from that article.Sclerotinia apothecia tend to be more common in moist conditions. These tiny mushroom shoot up spores that land on canola petals. Source: Faye Dokken-Bouchard, Saskatchewan Ministry of AgricultureThis is an apothecia, a tiny golf-tee shaped mushroom that grows from Sclerotinia sclerotiorum sclerotia in the soil. Apothecia germinate after warm summer rains. After a rain, how many days does it take for apothecia to mature and release ascospores into the canopy?
67. Ascospores cannot infect canola plants directly. What gives them the energy to produce the hyphae that release oxalic acid and other infection agents the fungus needs to invade healthy plant tissue?
68. What is the key risk factor for sclerotinia stem rot? Without this factor, disease levels will be much lower.
69. Fungicide application can significantly reduce yield losses from sclerotinia stem rot as long as the key risk factor in question 7 is present, and as long as fungicide is applied at the right time. What is the ideal time to spray?
70. Scouting for sclerotinia stem rot infection before or during swathing is a good time to assess disease severity. This assessment will help with management decisions in following years. What are typical symptoms of sclerotinia stem rot infection?


71. Your name (first and last):

72. Your CCA or CCSC number:

73. Email address:

74. Phone number: