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Pre-Emergence Herbicides for Wheat

By Sarah Lancaster
 
Pre-emergence herbicides with residual activity are an important component of high-yielding cropping systems. They are used less frequently 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 production.
 
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 without residual activity 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 be aware of planting interval restrictions for Group 4 herbicides, which range from 10 to 45 days.
 
One new product is Pixxaro. Pixxaro is a combination of two Group 4 herbicides: fluroxypyr (Starane Ultra, others) and halauxifen (Elevore). It is labeled for control of emerged weeds both before wheat planting and after emergence when wheat is at the 2-leaf through flag leaf stage. The application rate for both timings is 6 fl oz/A.
 
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. Selected 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

Dicamba

Dicamba

4

BD

Apply at least 45 days before planting wheat

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;
If dry, apply POST

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;
Rainfall necessary for activation to control PRE

Scorch

Fluroxypyr + dicamba

4 + 4

BD

Apply at least 30 days before planting wheat

Sharpen

Saflufenacil

14

BD, PRE

Rainfall required for activation;
Injury may occur to exposed wheat seed

Zidua

Pyroxasulfone

15

DPRE

Rainfall required for activation;

Plant wheat 1 – 1.5” deep

 
*BD = burndown; PRE = pre-emergence to wheat and weeds; DPRE = Delayed pre-emergence application after wheat emergence; POST = post-emergence
 
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 and update use requirements.
Source : ksu.edu