1. Winter survival of canola Cover Your Acres Conference Kansas Hay and Grazing Conference 5 4. Happy holidays!

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1 Number 171 December 23, Winter survival of canola Cover Your Acres Conference Kansas Hay and Grazing Conference 5 4. Happy holidays! 7 1. Winter survival of canola The recent bitterly cold temperatures have producers asking the question: Will my canola survive the winter? That's a good question, yet it has a complicated answer. A thriving winter canola crop depends upon the genetics of the cultivar, the environment in which it is grown, and the producer's management practices. The interaction of these factors will ultimately determine whether a crop will survive harsh winter weather conditions. Winter canola that was planted on time and in good soil moisture has the greatest potential for surviving the winter. As long as the crown is alive (healthy green color and firm when squeezed) and remains at the soil surface, the plants should initiate new growth in the spring as warm temperatures return. The rosette stage is when winter canola is most tolerant to cold temperatures. During this stage, a crown develops at the ground with larger, older leaves at the base and smaller, newer leaves at the center. The stem length remains unchanged but thickens. Five to 8 true leaves and 6" to 8" of fall growth is necessary for optimum winter survival. This fall growth will die back as the canola plants enter winter dormancy. Too much fall growth results in reduced moisture and nutrient availability in the spring, an elevated and more exposed growing point, and a high risk of winterkill. Too little fall growth results in low carbohydrate reserves, inadequate root and crown development, and a high risk of winterkill. Hardening begins in the rosette stage after several days of near-freezing temperatures. Hardened winter canola can withstand below 0 F temperatures, but it can also "un-harden" when temperatures increase for an extended period of time. Ultimately, it may not be the cold temperatures that cause winterkill but the rapid fluctuations in temperature, which can be common in Kansas during the winter. Additionally, extended periods of bitterly cold 1

2 temperatures without snow cover may be detrimental to survival. Whenever snow cover is present, winter survival should be enhanced. There are differences in winter hardiness among varieties. To increase canola s consistency in a region, cultivars that utilize all of a genotype s winter hardiness need to be developed. Our canola breeding program continues to select for winter hardiness. We are working with several European accessions that have a longer vernalization requirement. Additional research is needed to verify if a longer vernalization requirement has a major impact on winter hardiness. Winter hardiness is an important trait to consider when selecting a cultivar for your winter canola cropping system. More winter hardy products are being developed by public institutions and private industry; however, performance of these products may be variable in different environments. The table below shows percent survival of some commercial winter canola products from select locations of the National Winter Canola Variety Trial in the Southern Great Plains. Percent of plant survival for select commercial cultivars and hybrids in NAME MARKETER TYPE 1 TRAITS 2 Garden Parson Manhatta Wals Enid City s n h OK KS KS 3 KS 3 CO HyClass Croplan Hyb RR W Genetics Kronos Croplan Hyb Genetics Virginia Croplan OP Genetics Flash Miles Hyb Hornet Miles Hyb Hybristar Miles Hyb Kadore Miles OP Sumner Certified OP SU Wichita Certified OP DKW41-10 DeKalb OP RR DKW45-10 DeKalb OP RR DKW46-15 DeKalb OP RR, SURT DKW47-15 DeKalb OP RR, SURT LSD (0.05) CV OP = open pollinated, Hyb = hybrid; 2 RR = Roundup Ready, SU = sulfonylurea herbicide carryover tolerance, SURT = sulfonylurea residual tolerance; 3 = harvest data compromised by spring weather 2

3 Other factors to consider when selecting a variety or hybrid include yield potential, seed oil content, maturity, lodging tolerance, shatter resistance, and herbicide resistance to name a few. So, back to the original question: Will my winter canola survive the winter? Much remains to be seen, though the recent cold temperatures should not be cause for alarm. The decline in plant growth and loss of leaf tissue is a natural process heading into winter dormancy. When scouting your canola periodically this winter, check for a green, healthy crown. If you find that, then expect to see a blooming canola field this spring. -- Mike Stamm, Canola Breeder, K-State and Oklahoma State University mjstamm@ksu.edu Cover Your Acres Conference K-State s Northwest Area Research-Extension Center is once again organizing the popular Cover Your Acres Winter Conference in Oberlin, and the agenda is great. The dates this year are January 20 and 21, The conference is co-sponsored by K-State Research and Extension and the Northwest Kansas Crop Residue Alliance. For more information, see the flyer below or contact Brian Olson, Northwest Area Extension Crops and Soils Specialist at: bolson@ksu.edu -- Steve Watson, e-update Editor swatson@ksu.edu 3

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5 Kansas Hay and Grazing Conference The 2009 Kansas Hay and Grazing Conference will be held on Wednesday, January 14 at the Kansas Farm Bureau building, 2627 KFB Plaza, in Manhattan. This is a public conference, open to anyone interested in livestock grazing, hay production and utilization, or buying and selling of Kansas grass and hay products. The agenda and registration form is included below, or you can call Steve Watson, e-update Editor swatson@ksu.edu 5

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7 4. Happy holidays! There will be no Agronomy e-update during the upcoming holiday season (Dec. 24-Jan 2). We ll be back the first week of 2009 with another exciting year of updates from K-State Agronomy. Happy holidays! -- Steve Watson, Agronomy e-update Editor These e-updates are a regular weekly item from K-State Extension Agronomy and Steve Watson, Agronomy e- Update Editor. All of the Research and Extension faculty in Agronomy will be involved as sources from time to time. If you have any questions or suggestions for topics you'd like to have us address in this weekly update, contact Steve Watson, swatson@ksu.edu, or Jim Shroyer, Research and Extension Crop Production Specialist and State Extension Agronomy Leader jshroyer@ksu.edu 7