Herbicide-resistance traits have created additional weed control options in alfalfa, canola, corn, soybeans, sugarbeets and wheat. However, traits may create confusion surrounding which herbicides can be applied safely and legally to the various crop trait packages. Misapplications due to confusion can be very costly and embarrassing for the producer and collaborating partners.
Weed management to prevent herbicide-resistant weeds requires a well-thought-out strategy. Best management practices should consider control of weeds present in the field as well as control during the cropping sequence. A weed management strategy including an assortment of herbicide mixtures along with nonchemical options is necessary to preserve the value of herbicides and herbicide-resistant traits.
It is important to read and follow label guidelines when applying herbicides to any crop. The label of some glyphosate products indicates they can be applied to Roundup Ready® and glyphosate-tolerant crops. Most glyphosate labels state the products are for use in Roundup Ready® crops or in crops that have the Roundup Ready® gene. Other glyphosate labels have language stating the glyphosate product can be applied to glyphosate-tolerant crops.
The tables below help clarify which herbicide products can be applied to various trait packages. You should always check seed tags and herbicide labels to ensure misapplications do not occur.
Herbicide trait tables
Table 1. Alfalfa herbicide-resistant traits and herbicides that can be used in combination with resistant traits. A checkmark indicates that alfalfa herbicide trait packages have resistance to various herbicide productsa.
Alfalfa herbicide trait | Glyphosate | Glufonsinate | Growth regulators |
---|---|---|---|
Conventional | |||
Roundup Ready alfalfab | ✓ |
aAlways consult herbicide labels for application requirements.
bAlways consult herbicide label to determine if glyphosate formulation is approved for RR alfalfa.
Table 2. Canola herbicide-resistant traits and herbicides that can be used in combination with resistant traits. A checkmark indicates that canola herbicide trait packages have resistance to various herbicide productsa.
Canola herbicide trait | Glyphosate | Glufosinate | ALS Inhibitors |
---|---|---|---|
Conventional | |||
Roundup Ready | ✓ | ||
Roundup Ready TruFlex | ✓ | ||
LibertyLink | ✓ | ||
Clearfield Canolab | ✓ | ||
SU Canolac | ✓ |
aAlways consult herbicide labels for application requirements.
bApply Beyond (imazamox) to Clearfield canola varieties.
cApply Draft (thifensulfuron and tribenuron) to SU Canola varieties.
Table 3. Corn herbicide-resistant traits and herbicides that can be used in combination with resistant traitsa. A checkmark indicates that canola herbicide trait packages have resistance to various herbicide productsb.
Corn herbicide trait | Glyphosate | Glufosinate | 2,4-D Cholinec | FOP ACCase Inhibitorsd |
---|---|---|---|---|
Conventional | ||||
Glyphosate Tolerant (GT) | ✓ | |||
LibertyLink (LL) | ✓ | |||
GT LL | ✓ | ✓ | ||
RR2 | ✓ | |||
RR2Y LLe | ✓ | ✓ | ||
Enlist | ✓ | ✓ | ✓ |
aTrait names often refer to insect resistance traits (Agrisure, Optimum, Yieldgard, etc.). Be sure to consult seed tags and product information to ensure herbicide trait packages.
bAlways consult herbicide labels for application requirements.
c2,4-D is labeled for corn. Only approved 2,4-D choline formulations are permitted for applications to Enlist corn (Enlist Duo, Enlist One) at higher rates or later stages of corn growth.
dAssure II only and not other FOP or ACCase inhibitors.
eAlways consult herbicide label to determine if glyphosate formulation is approved for RR corn.
Table 4. Soybean herbicide-resistant traits and herbicides that can be used in combination with resistant traits. A checkmark indicates that soybean herbicide trait packages have resistance to various herbicide productsa.
Soybean herbicide trait | Glyphosate | Glufosinate | 2,4-D Cholineb | Dicambac | HPPD Inhibitorsd |
---|---|---|---|---|---|
Conventional | |||||
Glyphosate Tolerant (GT) | ✓ | ||||
Roundup Readye | ✓ | ||||
Roundup Ready 2 Yielde | ✓ | ||||
Roundup Ready 2 Yield Xtende | ✓ | ✓ | |||
Roundup Ready 2 Yield Xtendflexf | ✓ | ✓ | ✓ | ||
LibertyLink (LL) | ✓ | ||||
LLGT27d | ✓ | ✓ | ✓ | ||
Enlist E3 | ✓ | ✓ | ✓ | ||
GT27 | ✓ | ✓ |
aAlways consult herbicide labels for application requirements.
bOnly approved 2,4-D choline formulations (Enlist Duo, Enlist One) are permitted for over-the-top application to Enlist E3 soybeans.
cOnly approved dicamba formulations (Engenia, FeXapan, Tavium, XtendiMax) are permitted for over-the-top application to Xtend and XtendFlex soybeans.
dGT27 and LLGT27 are resistant to isoxaflutole preemergence. No HPPD-inhibiting herbicide is approved for use in soybeans in the U.S. as of January 2020.
eAlways consult herbicide label to determine if glyphosate formulation is approved for RR soybeans.
fNot approved for commercial production in the U.S. as of March 2020.
Table 5. Sugarbeet herbicide-resistant traits and herbicides that can be used in combination with resistant traits. A checkmark indicates that sugarbeet herbicide trait packages have resistance to various herbicide productsa.
Sugarbeet herbicide trait | Glyphosate | Glufosinate | Growth regulators |
---|---|---|---|
Conventional | |||
Roundup Ready Sugarbeetsb | ✓ |
aAlways consult herbicide labels for application requirements.
bAlways consult herbicide label to determine if glyphosate formulation is approved for RR sugarbeets.
Table 6. Wheat herbicide-resistant traits and herbicides that can be used in combination with resistant traits. A checkmark indicates that wheat herbicide trait packages have resistance to various herbicide productsa.
Wheat herbicide trait | Glyphosate | Glufosinate | ALS inhibitors |
---|---|---|---|
Conventional | |||
Clearfield Wheatb | ✓ |
aAlways consult herbicide labels for application requirements.
bApply Beyond (imazamox) to Clearfield wheat varieties.
CAUTION: Mention of a pesticide or use of a pesticide label is for educational purposes only. Always follow the pesticide label directions attached to the pesticide container you are using. Be sure that the area you wish to treat is listed on the label of the pesticide you intend to use. Remember, the label is the law.
Reviewed in March 2020