Growers FAQs

Fertilizer costs are slightly higher than for either winter or spring wheat. Nitrogen (N requirements are a little higher and it is important to have adequate sulfur on canola - see question about fertilizer). Fortunately, canola is very efficient at accessing more and deeper nutrients than wheat. Seed cost for spring canola is typically double that of winter canola, and traited canola seed is higher priced than open-pollinated varieties. Herbicide costs will depend on your weed spectrum and resistance traits of the canola, e.g. Roundup Ready.® Canola may require insecticide application. Seed supplier information can be found under the For Growers tab. Information on Fertilizer Management can found on the Production Strategies page of the For Growers tab. 

Fertilizer needs are somewhat similar to wheat, with nitrogen requirements higher than for wheat. A rule of thumb is seven lbs N/100 lbs of expected yield, and keep in mind, that amount includes what is in the soil before seeding. There are several nitrogen-specific publications based on PNW university research available under the Resources and Research tab.

A very important nutrient is sulfur (S) — the recommended ratio of N:S is 4:1. Other nutrients canola requires are phosphorus, potassium, and boron. There are studies underway at Washington State University and the University of Idaho to determine responses to micronutrient applications at different times during the growth season. The single best practice to determine nutrient needs is to soil test regularly. More information on growing canola can be found on our Production Strategies page under For Growers. 

Fertilizer should not be applied with the seed. A separation of at least one inch and preferably two inches is recommended. Take a look at the fertilizer management publications for a lot of great information about canola fertilizer recommendations and strategies for the PNW.

Herbicide history is THE most important information required before growing canola. Canola is very sensitive to Group 2 herbicides, but the good news is that the number of spring and winter varieties available that have residual herbicide resistance continues to grow. For in-season applications, several grass herbicides are labeled for canola. Herbicide-tolerant canola varieties allow the use of specific herbicides in-crop, e.g. glyphosate (Roundup Ready®) or glufosinate (Liberty Link®). A chart of herbicide plant-back restrictions for canola is posted in the Production Strategies page.

That will depend on the variety and yield potential. Winter and spring canola can be produced on as little as 10-12 inches of available water (growing season precipitation + soil water) and will yield higher with more water and adequate fertility. Irrigated canola requires 11-18 inches supplemental irrigation depending on rainfall, soil type, and evaporation rates. More tips for growing canola can be found on our Production Strategies under the For Growers tab. 

If the soil is uniform from the seed to the soil surface, the seed should keep pushing through to emergence. When the soil is soft underneath the crust, the cotyledons will tend to follow the path of least resistance and not push through the crust. A coil packer can be used to break apart crust with minimal disturbance if timed properly.

Canola is a self-pollinated crop. Only hybrid canola seed production has special pollination requirements. Commercial canola fields have no pollination requirements; however, there is ample anecdotal evidence of increased yield when pollinators are present in canola. Canola is an excellent forage source for honey bees and other pollinators. Beekeepers often seek out canola fields to place bees. Growers are advised to work with beekeepers if insecticides are needed.

Resources:

• A list of PNW beekeepers who are interested in canola fields for their hives as well as links to other PNW honey bee resources can be viewed here. 
• Best Management Practices (BMPs) for Pollinator Protection in Canola Fields (includes input from PNW canola growers and university staff)
• More information on pollinators can be found on our Health Benefits & Pollinators page under the For Consumers menu. 

With increasing acreage of canola, there are also increasing reports of insect pests, yet most are cyclical, and all are treatable. Scouting regularly is important as populations can increase or decrease quickly, which will impact treatment decisions. The most common insect pests in the PNW are cabbage aphid, cabbage seedpod weevil, flea beetle, and diamondback moth. It is important to know the life cycle of these pests and scout fields at the proper time. Various pests attack canola from the seedling stage to post-flowering. Diseases haven’t gained much of a foothold in the PNW, primarily due to the environment, crop rotation intervals, and seed treatment. Blackleg, Rhizoctonia, and sclerotinia have all been observed in some areas of the PNW. Refer to our PNW Canola Publications and PNW Canola Research pages under Resources and Research for pest and disease information.

Yes, winter canola can be a dual-purpose crop. It is seeded earlier than normal, e.g. June; grazed or harvested for forage/silage in late summer or early fall, allowed to regrow before winter, then harvested for grain the following summer. See our PNW Extension Publications page under Research & Resources to read more about dual-purpose canola.