Growing Corn in Western Canada

The growth of corn acres continues to rise across Western Canada. Growers are using corn for various end uses, such as, grain corn for feed and fuel, silage corn for livestock, high moisture corn and grazing corn.

In order to grow a successful corn crop in Western Canada, you need to understand these key factors:

Corn Hybrid Selection

Fertility & Placement

Corn Heat Units (CHU)

Weed Control in Corn

Targeted Seeding Rate

Grain Dry Down

Field Preparation

Harvest & Corn Staging


One of the most important factors is hybrid selection. Your Pioneer Hi-Bred sales representative can provide you with excellent information on agronomics and a recommendation on which corn seed product to choose for your area. Below is a list of Pioneer® brand corn seed products available in Western Canada.

To track your Corn Heat Units for the current year, click here.


DuPont Pioneer assigns corn heat unit (CHU) values to help position hybrids in the field. Corn heat units are a system of relatively ranking hybrids for their maturity as determined by the level of moisture a hybrid has at harvest.

Look at the corn heat unit rating of the hybrid you are considering and the physiological maturity for your area (see maps below) to best determine whether a hybrid can be safely planted on your farm. Depending on the end purpose of your corn crop, you must select an appropriate heat unit corn to achieve the desired maturity.

When selecting corn hybrids for your local conditions, it is best to work with someone that understands the area. That person is your local Pioneer Hi-Bred sales representative.


Physiological maturity courtesy of the Government of Alberta – Agriculture and Rural Development. Average Corn Heat Unit accumulations from 1981 to 2010.


Physiological maturity courtesy of the Saskatchewan Ministry of Agriculture. Accumulate Corn Heat Units for Grain Production. Data from 1980-2005.


Physiological maturity courtesy of Manitoba Agriculutre and Food. Average Annual Accumulation of Corn Heat Units.

For more information on corn heat units, contact your local PHI sales representative or click here.

Hybrid/Brand 1
Heat Units
Silk CRM
Phys. CRM
P6909R RR2 1950 73 70 NA
39F44 RR2 2000 73 70 72
P7005AM™ AM,LL,RR2 2000 70 74 77
P7202AM™ AM,LL,RR2 2050 72 69 76
P7211HR HX1,LL,RR2 2050 72 70 74
P7213R RR2 2050 72 75 74
P7332R RR2 2050 73 77 81
P7455R RR2 2100 74 74 NA
P7527AM™ AM,LL,RR2 2150 75 78 77
39B90 RR2 2200 79 82 79
P7632AM™ AM,LL,RR2 2225 76 77 81
39V05 RR2 2250 80 84 85
39V09AM™ AM,LL,RR2 2275 80 84 85
P7958AM™ AM,LL,RR2 2275 79 84 83
P8234AM™ AM,LL,RR2 2400 82 84 85
P8210 Conventional 2425 82 80 81
P8387AM™ AM,LL,RR2 2500 83 85 86
P8542AM™ AM,LL,RR2 2550 85 86 87
P8673XR HXX,LL,RR2 2550 86 86 84
P8581R RR2 2575 85 88 87
P8700AM™ AM,LL,RR2 2600 87 85 87
P9188 Conventional 2600 91 89 91
P9789AMXT™ AMXT,LL,RR2 2600-2900 97 99 96
P9188AM™ AM,LL,RR2 2650 91 89 91
P9330AM™ AM,LL,RR2 2700 93 95 94
P9840AM™ AM,LL,RR2 2900 98 97 100
P0496AMX™ AMX,LL,RR2 3100 104 104 106


Trait rating scores provide key information useful in selection and management of Pioneer® brand hybrids in your area. Information and ratings are based on comparisons with other Pioneer brand hybrids, not competitive hybrids. Information and scores are assigned by Pioneer Research Managers. Scores are based on period-of-years testing through 2014 harvest and were the latest available at time of printing. Some scores may change after 2015 harvest. Scores represent an average of performance data across areas of adaptation, multiple growing conditions, and a wide range of both climate and soil types, and may not predict future results. All products within a hybrid family receive the same score unless observations indicate a significant difference. Individual product responses are variable and subject to a variety of environmental, disease and pest pressures. Please use this information as only one component of your product positioning decision. Refer to or contact a Pioneer sales professional for the latest and most complete listing of traits and scores for each Pioneer brand product.


9 = Outstanding; 1 = Poor; Blank = Insufficient Data.


AM — Optimum® AcreMax® Insect Protection system with YGCB, HX1, LL, RR2. Contains a single-bag integrated refuge solution for above-ground insects.

AMXT (Optimum® AcreMax® XTreme) — Contains a single-bag integrated refuge solution for above- and below-ground insects. The major component contains the Agrisure® RW trait, the YieldGard® Corn Borer gene, and the Herculex® XTRA genes.

AMX (Optimum® AcreMax® Xtra) — Contains a single-bag integrated refuge solution for above- and below-ground insects. The major component contains the YieldGard® Corn Borer gene and the Herculex® XTRA genes for resistance to corn borer and corn rootworm.

HX1 — The Herculex® I insect protection trait offers a high level of resistance to European corn borer; very good resistance to black cutworm and western bean cutworm; and moderate resistance to corn earworm.

HXX — Herculex® XTRA contains the Herculex I and Herculex RW genes for resistance to the same pests as Herculex I as well as protection against larvae of western corn rootworm and northern corn rootworm.

LL — Contains the LibertyLink® gene for resistance to Liberty® herbicide.

RR2 — Contains the Roundup Ready® Corn 2 trait that provides crop safety for over-the-top applications of labelled glyphosate herbicides when applied according to label directions.

YGCB — The YieldGard® Corn Borer gene offers a high level of resistance to European corn borer; and moderate resistance to corn earworm.  

Herculex® insect protection technology by Dow AgroSciences and Pioneer Hi-Bred.®, ™ Herculex and the HX logo are trademarks of Dow AgroSciences LLC.  Liberty®, LibertyLink® and the Water Droplet Design are trademarks of Bayer. Roundup Ready®, YieldGard® and the YieldGard Corn Borer design are registered trademarks used under license from Monsanto Company. Agrisure® technology incorporated into these seeds is commercialized under a license from Syngenta Crop Protection AG

CRM (Comparative Relative Maturity):

There is not an industry standard for maturity ratings so comparing hybrid maturity and harvest moisture ratings between companies is usually difficult. Use the CRM rating to compare Pioneer hybrids with competitive hybrids of a similar maturity and harvest moisture. CRM ratings, and harvest moistures, for hybrids within a family may vary slightly, depending upon the level of insect (ECB and CRW) infestation. Conventional and straight hybrids with the RR2 gene within a family will usually be 1-2 CRMs earlier than indicated, when insect infestations are moderate to heavy. One CRM difference is about ½ point of moisture difference at harvest.


Measures differences in maturity to zero milkline stage. To help decide if a new hybrid fits your area’s growing season, compare its physiological CRM to a hybrid that you plant or one that is successfully used in your area.


Compares hybrids of similar maturity for rate of moisture loss during grain drydown. A higher score indicates faster drydown. A lower score indicates slower drydown, or a wider opportunity for silage and high-moisture corn harvest.


All hybrids are expected to establish normal stands under average soil conditions. Stress emergence is a measure of the genetic ability or potential to emerge in the stressful environmental conditions of cold, wet soils or short periods of severe low temperatures, relative to other Pioneer hybrids. Ratings of 7-9 indicate very good potential to establish normal stands under such conditions; a rating of 5-6 indicates average potential to establish normal stands under moderate stress conditions; and ratings of 1-4 indicate the hybrid has below average potential to establish normal stands under stress and should not be used if severe cold conditions are expected immediately after planting. Stress emergence is not a rating for seedling disease susceptibility, early growth or speed of emergence.


Drought tolerance is a complex trait, determined by a platform's ability to maintain yield in limited-moisture environments. A higher score indicates the potential for higher yields vs. other platforms of similar maturity in limited-moisture environments.


HS - Highly Suitable; S – Suitable; MA – Manage Appropriately; X - Poorly Suited. Suitability rating based on field observations and a weighted calculation of gray leaf spot, stress emergence, anthracnose stalk rot, northern corn leaf blight, and Diplodia ear rot scores. High Residue Suitability ratings may vary by environment and geography.


Higher score indicates heavier test weight.


9 = Very Tall; 1 = Short.


Ratings determined by frequency and severity of stalk snappage at lower to middle stalk internodes from conditions usually favored by rapid or optimum growth. Relative response of hybrids can be affected by planting date, stage of growth, rate of growth, wind severity and other variables. Scores derived from both natural observations and artificial evaluation immediately prior to tasseling. NOTE: Scores do not reflect snappage enhanced by or due to herbicide interaction. The use of growth regulator herbicides such as 2,4-D and dicamba can increase the brittle snap potential of corn hybrids. Hybrids with lower brittle stalk ratings will require more caution and have a higher risk associated with the use of growth regulator herbicides. Early application, proper rates and application methods, along with both hybrid and herbicide selection can help reduce this risk. BRITTLE STALK PRECAUTION: In areas with higher potential for brittle stalk breakage, growers must balance the risk of planting hybrids with brittle stalk ratings of less than 4 against the overall performance of more resistant hybrids with higher ratings. All hybrids have a period of susceptibility to brittle stalk. Hybrids with below average ratings may have a longer period of susceptibility, or may experience more severe breakage relative to hybrids with higher scores during period of susceptibility.


Grower should balance hybrid yield potential, hybrid maturity and cultural practice selection against their anticipated risk of a specific disease and need for resistance. In high disease-risk conditions, consider planting hybrids with at least moderate resistance ratings of 4 or higher to help reduce risk. When susceptible hybrids with disease ratings of 1 to 3 are planted in conditions of high disease pressure, the grower assumes a higher level of risk. If conditions are severe, even hybrids rated as resistant can be adversely affected. Independent of yield reduction, diseases can predispose plants to secondary diseases such as stalk rots. This requires individual field and hybrid monitoring for stalk stability and timely harvest when warranted.


8-9 = Highly Resistant; 6-7 = Resistant; 4-5 = Moderately Resistant; 1-3 = Susceptible; Blank = Insufficient Data.


In conditions where northern leaf blight (NLB) risk is high, growers should consider planting only hybrids with at least moderate NLB resistance ratings of 4 or higher.


Ratings based upon visual symptoms at harvest. If Gibberella ear rot has caused significant damage in the past, growers should consider planting only hybrids with at least moderate Gibberella ear rot ratings of 5 or higher.