Pre-emergence herbicides with residual activity are an important component of high-yielding cropping systems. They are not emphasized as much in wheat production compared to other cropping systems in Kansas, but residual herbicides applied prior to wheat emergence can be part of a good weed management system in wheat. Selected products for this use are described in Table 1.
Most residual herbicides labeled for pre-emergence application in wheat are Group 2 (ALS-inhibiting) herbicides, which are associated with herbicide-resistant populations of kochia, marestail (horseweed), bushy wallflower, flixweed, henbit, and brome species in Kansas. Products in Groups 14 (the PPO-inhibiting herbicides) and 15 (the long-chain fatty acid-inhibiting herbicides) are also labeled; however, they are generally more dependent on rainfall for activation than the Group 2 herbicides.
Herbicides to control emerged weeds may be applied with or without residual herbicides in the weeks prior to planting wheat. Older products include the Group 2 herbicides Amber, Olympus, and Pre-Pare, as well as Group 4 (plant growth regulating) herbicides like 2,4-D, dicamba, or fluroxypyr. It is especially important to know planting interval restrictions for Group 4 herbicides, which range from 10 to 45 days.
When selecting pre-emergence herbicides for use in wheat production, keep in mind that many of these products are also labeled for use in emerged wheat. Unless using a planned split application, avoid repeated use of products from the same herbicide group to slow the development of herbicide-resistant weed populations in your fields.
Table 1. Select herbicides for pre-emergence or pre-plant applications in winter wheat.
|
Trade name |
Common name |
Herbicide group |
Application timing* |
Comments |
|
Amber |
Triasulfuron |
2 |
BD, PRE, or POST |
Requires tank mix or sequential application of herbicide from different group |
|
Anthem Flex |
Pyroxafulfone + carfentrazone |
15 + 14 |
DPRE |
Plant wheat 1 – 1.5” deep |
|
several |
Dicamba |
4 |
BD |
Apply at least 45 days before planting wheat |
|
Facet |
Quinclorac |
4 |
BD |
Plant wheat at least 1” deep |
|
Finesse |
Chlorsulfuron + metsulfuron |
2 + 2 |
PRE, POST |
Suppression only of cheat, downy brome, and Japanese brome |
|
Kochiavore |
Fluroxypyr + bromoxynil |
4 + 6 |
BD |
Apply at least 30 days before planting wheat |
|
Olympus |
Propoxycarbazone |
2 |
PRE, POST |
Mix with glyphosate for BD |
|
Outrider |
Sulfosulfuron |
2 |
PRE, POST |
Apply after planting but before wheat emergence; |
|
Pixxaro |
Fluroxypyr + halauxifen |
4 + 4 |
BD, POST |
Do not use multiple applications or in successive years at the same site |
|
Pre-Pare |
Flucarbazone |
2 |
BD, PRE |
Mix with glyphosate for BD; |
|
Quelex |
Halauxifen + florasulam |
4 + 2 |
BD, POST |
Broadleaf weed control only |
|
Reviton |
Tiafenacil |
14 |
BD |
Mix with glyphosate for grass activity |
|
Scorch |
Fluroxypyr + dicamba |
4 + 4 |
BD |
Apply at least 30 days before planting wheat |
|
Sharpen |
Saflufenacil |
14 |
BD, PRE |
Rainfall required for activation; |
|
Zidua |
Pyroxasulfone |
15 |
DPRE |
Rainfall required for activation; Plant wheat 1 – 1.5” deep |
|
several |
2,4-D |
4 |
PRE, POST |
Apply at least 2 weeks after a 0.5” rainfall before planting wheat |
*BD = burndown; PRE = preemergence to wheat and weeds; DPRE = Delayed preemergence application after wheat emergence; POST = postemergence
For additional information, see the “2024 Chemical Weed Control for Field Crops, Pastures, and Noncropland” guide available online at https://bookstore.ksre.ksu.edu/pubs/SRP1183.pdf or check with your local K-State Research and Extension office for a paper copy.
The use of trade names is for clarity to readers and does not imply endorsement of a particular product, nor does exclusion imply non-approval. Always consult the herbicide label for the most current use requirements. Users should read and follow all label requirements.
Sarah Lancaster, Extension Weed Science Specialist
slancaster@ksu.edu