CANOLA WEED MANAGEMENT Eric P. Prostko and Tim L. Grey Extension Weed Specialist and Research Weed Scientist The University of Georgia April 2007

Before Getting Started  What herbicides were used in previous crops?  Canola is very sensitive to herbicide residues!!

Canola Rotation Restrictions Herbicide Canola Plant-Back Atrazine 12 months Accent 10 months (≤ 6.5 pH) Cadre 40 months 0 (?) months (Clearfield) Classic 18 months Direx 24 months Envoke 18 months + FB Reflex 18 months Staple 10 months + FB Strongarm 30 months + FB Valor 12 months + FB FB = Field Bioassay

Avoid Planting Canola in Wild Radish/Mustard Fields

Follow All UGA Recommended Production Practices  Adapted Variety  Planting Date –North Zone (September 10 to October 25) –South Zone (October 10 to November 15)  Row Spacing (6-12”)  Seeding Rate (4-6 lbs/A)  Fertility Management

Herbicides For Use in Georgia Canola  Glyphosate – at-planting but before crop emergence  Treflan,Trilin, etc. –PPI  Select/Arrow, Poast, Assure/Targa –POST (grass control)  Beyond –POST –Clearfield varieties only!!!!

Trifluralin in Canola  Incorporate to depth of 2- 3” within 24 hours of application  2-pass system  lb ai/A  some control of winter annual grasses, henbit, and chickweed  no control of wild radish/mustard  Better than nothing!

 Clearfield Canola Production Systems  Non-GMO  Beyond (imazamox) is only herbicide registered for use in U.S.  Based on UGA field trials, eliminates concerns for Cadre (imazapic) carryover problems. However, Clearfield canola is NOT listed on Cadre label.

 Clearfield Canola varieties only!!!!!  Beyond 1AS (imazamox)  4 oz/A % v/v + 2.5% v/v  weeds less than 3” tall  In UGA field trials, Beyond has provided good to excellent control of Italian ryegrass, wild radish and shepherd’s-purse when applied between 24 and 37 DAP.  $515/gal ($16.09/A)

 ROTATIONAL CROP RESTRICTIONS FOR BEYOND  3 months = wheat  4 months = barley, rye  8.5 months = field/sweet corn  9 months = cabbage, cantaloupe, carrot, cotton, cucumber, grain sorghum, oats, onion, peanut, pepper, tobacco, tomato, turnip, watermelon  18 months = non-Clearfield canola

Weed Control in Clearfield Canola with Beyond 1AS (4 oz/A) + COC (1% v/v) + 37% UAN (2 qts/A) WeedTiming ’ ’Average Wildradish 24 DAP DAP Italian ryegrass 24 DAP DAP Henbit 24 DAP DAP Shepherd’s- purse 24 DAP DAP Wild garlic 24 DAP DAP Grey et al Weed Technology 20:

Stinger  clopyralid  labeled but not yet recommended by UGA  3 lb ai/gal  4-8 oz/A ($15-30/A)  2 to 6 leaf stage of canola  50 day PHI  Canada thistle, sowthistle, dandelion, chamomile  Rotations –0 months = field corn, wheat, barley, oats –10.5 months = grain sorghum, onions, sunflowers –18 months = all other crops

Other Types of Herbicide- Resistant Canola  Roundup-Ready (RR)  Liberty-Link (LL)  both are not currently labeled for use in Georgia  Why? –Developed after Georgia stopped growing canola on a commercial basis – varieties more susceptible to blackleg – volunteer problem in other RR crops – herbicide resistance issues

Weed Control in RR-Canola with Roundup Weathermax 5.5SL (22 oz/A) WeedTiming ’ ’Average Wildradish 24 DAP DAP Italian ryegrass 24 DAP DAP Henbit 24 DAP DAP Shepherd’s- purse 24 DAP DAP Wild garlic 24 DAP DAP Grey et al Weed Technology 20:

Weed Control in LL-Canola with Liberty 1.67SL (34 oz/A) + 21% AMS (3 lb/A) WeedTiming ’ ’Average Wildradish 24 DAP DAP Italian ryegrass 24 DAP DAP Henbit 24 DAP DAP Shepherd’s- purse 24 DAP DAP Wild garlic 24 DAP DAP Grey et al Weed Technology 20:

UGA Weed Science