From the table below, few herbicides are available for small grain application when vegetables will be planted after harvest. Harmony or Harmony Extra can be used with the ability to plant vegetables; Axial XL too can be used in very early spring. However, Starane Ultra applications in the spring are difficult to allow vegetable rotations, for instance an application March 7 prevents a planting date before July 7.
|Selected Herbicides||MOA (group)||Rotation for Veggies||Applications with Nitrogen|
|Harmony SG||ALS / 2||1.5 months||Yes|
|Harmony Extra SG||ALS / 2||2 months||Yes|
|2,4-D||PGR / 4||3 months||Yes|
|dicamba (Banvel)||PGR / 4||after harvest||Yes|
|Axial XL||ACC / 1||90 days||Yes, liquid N should be no more than 50%|
|Starane Ultra||PGR / 4||120 days||Not specified, up to 20 gal/A of 30%|
|Osprey||ALS / 2||10 months||No, must separate N application and Osprey application by 14 days|
|PowerFlex||ALS / 2||9 to 12 months||Yes, Liquid N no more than 50% of the solution / total N less than 30 lbs|
|Finesse||ALS / 2||>14 months||Yes, no NIS if N is more than 50% of solution / requires use of STS soybeans|
|Maverick||ALS / 2||>18 months||Yes, N permitted, but not recommended when controlling annual bluegrass / requires use of STS soybeans|
When ALS-resistant chickweed is present, none of the alternative products are nearly as effective or as flexible as Harmony Extra, Osprey, or PowerFlex. From the table above, you can see that ALS herbicides are widely used in small grains (and other crops). So if you do not have resistant biotypes take steps to prevent them. One method is to not use ALS herbicides (Group 2) as fall treatments, early spring burndown, or preplant in corn or soybeans.
● ALS chickweed control: Starane Ultra is the best option, but level of control is about 60 to 70% suppression rather than 95% control. 2,4-D and dicamba are not as effective as Starane Ultra.
● ALS annual ryegrass (Italian ryegrass): Osprey or PowerFlex will not control them; Axial XL is the only option for POST treatment. However, be aware that Axial XL is a Group 1 herbicide and resistance has been reported in other regions to Group 1 herbicides, so do not overuse Axial and take precautions to prevent ryegrass from producing seeds in no-till situations.
● ALS horseweed: there is limited data on best method to manage this biotype in small grains. The considerations are a balance between effective control and crop safety. Dicamba (Clarity) and 2,4-D have some activity on horseweed, but there are concerns about crop safety. And using lower rates to reduce the potential of crop injury it may also reduce control horseweed control. UD has not had experience with Starane Ultra or other available herbicides for spring treatments.