In this issue:
(click the bookmark links below to move to specific sections of this report)
Crop development varies
Variable precipitation received
Excess moisture stress affecting more areas
Hail damage could slow plant development
Scout fields regularly
Prolific weed growth continues
Herbicide residue symptoms reported
Is a second herbicide pass required?
Top dressing may make sense
Cutworms reported
Flea beetles damaging canola in Peace
Scout for cabbage seedpod weevils
Make sure those grasshoppers are actually canola pests
Lygus bugs can cause economic damage
Gopher damage reported in Saskatchewan
Assess sclerotinia risk
The Alberta Canola Producers Commission (ACPC) has developed an Alberta focused version of this report. Visit the ACPC website at: http://www.canola.ab.ca
Crop development varies widely based largely on when the crop was seeded. Some earlier seeded crops in Manitoba, north-western Saskatchewan and southern Alberta are starting to bloom, whereas crops in other areas seeded in early June are just emerging. Patchy emergence continues to be an issue throughout many areas of north-central Alberta from Barrhead to Vegreville, with problems more evident on later seeded and broadcast seeded fields, especially on hill tops and sandy or solonetzic areas.
The latest crop report from Manitoba Agriculture, Food & Rural Initiatives is available at: http://web2.gov.mb.ca/agriculture/mwcr/index.php
The latest crop report from Saskatchewan Agriculture, Food & Rural Revitalization is available at:
http://www.agr.gov.sk.ca/docs/reports/crop_report/crprpt070617.asp
Variable precipitation from trace amounts to over 175 mm was received across many parts of the west. For current maps of moisture conditions from PFRA for western Canada, check the following links for precipitation since September 1 and April 1 respectively:
http://www.agr.gc.ca/pfra/drought/prpay07_e.htm
http://www.agr.gc.ca/pfra/drought/prpgs07_e.htm
Additional moisture information for Alberta is available from Alberta Environment at: http://www3.gov.ab.ca/env/water/WS/data/precipmaps/weekly.pdf
Excess moisture remains the largest crop development issue across western Canada. Areas with excess moisture increased over the past week and now include most of Manitoba, southeastern, north-central and northeastern Saskatchewan and central Alberta between Didsbury and Ponoka. Wet soils slow down or stop gas exchange between the soil and atmosphere, causing an oxygen deficiency, reducing root respiration and plant growth. Canola is quite susceptible to waterlogging and yield reductions can occur after only three days of flooding. Symptoms include changes in plant colour such as yellowing or purpling, stunted growth, premature bolting (small and spindly canola plants that are starting to bolt) and older leaves turning purple and senescingmore rapidly. For further information regarding the effects of excess moisture on canola growth, refer to the following link: http://www.canola-council.org/excessmoisture.aspx.
The degree of damage and yield loss will depend on several factors including crop growth stage at the time of waterlogging, soil type and texture, duration of saturated soil and temperature (Figure 1). High temperatures combined with waterlogged soils may reduce yields further.
Figure 1. Effect of Water Logging on Yield
**Canola Growers Manual, 2003 edition, page 405**
Many nutrient deficiency symptoms including nitrogen and sulphur often occur on crops that are flooded. This is due to the fact that the roots are not functioning properly due to the lack of oxygen. Allow the crop to recover before assessing whether or not additional nutrients may need to be top-dressed. Remember that canola can respond well to top dressed sulphate fertilizer right up to bolting and early flower, while economic responses to nitrogen are most likely to occur if top dressing is done prior to the 4-6 leaf stage. Keep in mind the stage of the crop and also the relative growth of the crop. A crop developing poorly due to other stresses such as excess moisture or weed competition is not as likely to respond to additional nutrients as healthier crops.
Hail was also reported across many areas, usually in conjunction with relatively localized thunderstorms. Hail damage at this stage of the crop usually results in a delay in development, as the plant channels its resources into rebuilding the damaged parts before advancing growth. If possible, herbicide applications should be avoided until signs of recovery are evident to help ensure good crop tolerance and adequate uptake by the weeds present. Canola stands with lower than optimal plant density will need careful management. Properly timed weed and insect control will be critical to allow the crop to compensate. Maturity will also likely be extended.
Remember to keep scouting fields on a regular basis to detect crop development problems early. Consider establishing a scouting tramline by driving an ATV in an ‘X’ or ‘W’ pattern in the field to establish pathways for crop scouting. This will allow for easier scouting with minimal trampling at later crop stages, especially once the crop is blooming.
Prolific weed growth continues in many areas due to the favourable moisture conditions. Delays in herbicide application continue in many areas due to high winds and/or frequent rainfall. However, because many areas have also experienced hail or standing water, it is important that growers give the crop some time to recover from these stresses before applying another stress in terms of herbicide application. These stress conditions also often lead to poor weed control as well.
Growers are strongly encouraged to assess the number, growth stage and types of weeds present prior to herbicide applications. Also, remember to read herbicide labels. With several herbicides available in various formulations (e.g. glyphosate), as well as various possible tank-mix combinations, it is important that the correct rate and timing of product(s) are applied to ensure good weed control and crop tolerance. Also, ensure that proper tank cleanout procedures are followed when switching herbicides and crops to reduce chances of subsequent crop injury. For further comments including specific weed-herbicide recommendations, tank-mix options and spraying tips, refer to the June 6th report at:
http://www.canola-council.org/Canola_Watch_Report_2007_06.html
Herbicide residue symptoms continue to be reported in the Peace region near Manning. To assist in identification of herbicide residues on canola, refer to the following Canola Council Herbicide Residue Injury Guide at: http://www.canola-council.org/PDF/toolbook.pdf#zoom=100
Early seeded crops in many areas have received their first herbicide pass and growers are considering a second application. Prior to automatically applying the second herbicide pass, first consider whether or not the second pass is warranted given the remaining weed pressure. Also, if the canola canopy is starting to reach complete ground cover, the herbicide may not reach targeted weeds. Growers are cautioned when applying late first applications or the second applications of herbicides when the crop is in the bud stage; late spraying could potentially lead to crop stress and blanks on the main stem. Refer to the following Canol@Fact (http://www.canola-council.org/PDF/Jun13_Canola_Fact_Sheet.pdf )for more information on weed control timing including second applications and to the following Canol@Fact at http://www.canola-council.org/PDF/May24_How_Many_Weeds.pdf for more information regarding weed populations and economic thresholds.
Top dressing of nitrogen and/or sulphur is being considered by many growers especially in northern and eastern Saskatchewan. This practice should be considered by growers who were conservative with their initial fertilizer applications for this crop or were unable to apply sufficient fertilizer at the time of seeding. Top dressing may also be considered in areas with excess moisture that may have experienced substantial nitrogen losses from saturated soils in low-lying areas. If the excess water recedes fairly quickly and the canola recovers, growers may need to consider top dressing additional nitrogen to compensate. Growers concerned about the nutrient status of their crop should consider tissue testing, but for recently flooded canola it is important to remember to allow for the plant to recover and growth to stabilize before tissue testing takes place. Ensure rates and field conditions are appropriate to minimize any detrimental effects to the crop, such as leaf burn. If considering products like fines, ensure the application equipment available will allow consistent coverage.
Cutworms continue to be reported in the southwestern region of Saskatchewan near Coderre, Eastend and Arelee and in Alberta near Mayerthorpe. Be especially vigilant in areas that had cutworm damage last year. Before considering control, check the size of cutworms and whether they are actively feeding. Cutworms nearing 38 mm (1.5 inches) long are not good candidates for control, since these worms are close to pupating, so be sure of the size before considering control measures. Also, cut open the abdomen of any located cutworms. Green material in the abdomen indicates active feeding which makes these worms favorable for control, whereas the absence of green material may indicate that these worms are close to pupating. For more information on cutworms, refer to the May 30 Canola Watch report: http://www.canola-council.org/Canola_Watch_Report_2007_05.html
Flea beetle damage continues to be reported in many areas of the Peace region, with lots of spraying occurring around Dawson Creek and Hines Creek. Crops at the 3-4 leaf stage should be able to begin outgrowing the damage, but fields at higher risk include those from short rotations or those without any seed treatment insecticides.
Cabbage seedpod weevils have been noted in southwestern Saskatchewan and throughout southern Alberta between Medicine Hat and Lethbridge. As earlier seeded fields are starting to flower, these fields are at most risk at this time of year and should be scouted frequently. For more tips on scouting and controlling cabbage seedpod weevil, refer to the following links: http://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/all/agdex2538
http://www.directfocus.com/canolamanual/chapter10b.html#ch10b_sec7
Grasshoppers have been reported in north-central Alberta near Barrhead, Alcomdale, Killam, Vermilion and St. Paul as well as parts of northwestern Saskatchewan. Although most damage from grasshoppers usually occurs on cereals and forage grasses, damage to canola can occur if other food sources are not present. Scout carefully to determine whether the species noted are actually pest species and whether damage is occurring to canola. For more information regarding identification of grasshoppers, refer to the following web link from Dr. Dan Johnson at the University of Lethbridge: http://people.uleth.ca/~dan.johnson/htm/dj_gh_guide.htm
Lygus bugs have been noted in southern Alberta and in the north Peace region near La Crete. Although economic damage from lygus occurs primarily in the pod stage, heavy populations at the bud and early bloom stage when the crop is suffering from additional stresses like drought can also cause economic damage. For more information on lygus, please refer to the following link: http://www.directfocus.com/canolamanual/chapter10b.html#ch10b_sec13
More damage from gophers (Richardson’s ground squirrel) continues in areas of southern and northwestern Saskatchewan. Some reseeding of fields has occurred as a result of the damage. Refer to the following AAF link for further information on management and control: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3471
Sclerotinia apothecia have been noted in fields in southeastern Manitoba. Wet fields combined with warm temperatures are favorable for sclerote germination and formation of apothecia. Where canola crops are entering the flowering stage, surrounding fields that produced host crops for sclerotinia (e.g. canola, pulses, sunflowers) last year are the primary candidates for scouting for apothecia.
Early seeded fields in many regions are now into bloom, with fungicide applications being considered. This is the time to scout individual fields to assess the risk for sclerotinia development and potential yield loss. The high levels of soil moisture in many areas combined with warm temperatures and crops at full ground cover, creates conditions that are conducive to sclerotinia development. Producers should carefully consider all of the factors highlighted in the sclerotinia stem rot checklist before making this decision. These factors include how heavy their crop canopy currently is, the amount of moisture received in the two weeks prior to flowering and potential for future rainfall, years since last host crop, disease incidence in the past, and the presence of apothecia in neighboring fields where host crops were grown previously. Target yield, fertility program and expected value of the canola crop are also points to consider.
A publication called the Canola Disease Identification and Sclerotinia Risk Assessment Card is available to assist growers and crop scouts with this decision. It includes the stem rot checklist as well as pictures to aid in accurately identifying the apothecia of the sclerotinia fungus. A PDF version can be found at http://www.canola-council.org/PDF/canola_plant_disease_risk.pdf#page=1 or contact your local Canola Council agronomist.
Direct questions regarding this report to John Mayko, Senior Agronomist, Parkland West (West Central AB), with the Canola Council of Canada at maykoj@canola-council.org ph/fax: 780-764-2593.
Direct specific questions regarding regional issues to one of the following Canola Council of Canada agronomists or provincial oilseed specialists:
Derwyn Hammond, Agronomist, Manitoba, hammondd@canola-council.org, 204-729-9011
Arvel Lawson, Manitoba Agriculture, Food & Rural Initiatives, Arvel.Lawson@gov.mb.ca, 204-745-0340
David Vanthuyne, Agronomist, Eastern Saskatchewan, vanthuyd@canola-council.org, 306-782-7799
Jim Bessel, Senior Agronomist, North-central/eastern Saskatchewan, besselj@canola-council.org, 306-373-6771
Penny Pearse/Scott Hartley, Saskatchewan Agriculture, Food & Rural Revitalization, ppearse@agr.gov.sk.ca / shartley@agr.gov.sk.ca , 306-787-4671 / 306-787-4669
Doug Moisey, Agronomist, Parkland East (East Central AB & NW SK), moiseyd@canola-council.org, 780-645-3624
Matthew Stanford, Agronomist, Chinook (Southern AB & SW SK), stanfordm@canola-council.org, 403-758-6660
Anne Vos, Acting Agronomist, Peace Region, av@summit-ag.com, 780-835-4632
Murray Hartman, Alberta Agriculture, Food & Rural Development, murray.hartman@gov.ab.ca, 403-782-8024
Kerry Clark, BC Ministry of Agriculture and Lands, Kerry.Clark@gov.bc.ca, 250-784-2559
The Canola Watch Report provides just-in-time information on canola production to growers and industry. Contributors to the Canola Agronomy Network are:
Manitoba Agriculture & Food; Manitoba Canola Growers Association; Agricore United; Saskatchewan Wheat Pool; United Farmers of Alberta; Saskatchewan Agriculture, Food & Rural Revitalization; Saskatchewan Canola Growers Association; Saskatchewan Canola Development Commission; Alberta Agriculture, Food & Rural Development; Alberta Canola Producers Commission; BC Ministry of Agriculture; Food & Fisheries; and the Canola Council of Canada.