Features
Agronomy
Weeds
A new ‘one-pass’ corn herbicide for Ontario
Evaluations shown from comparative trials.
November 14, 2007 By Mike Cowbrough and Dr. Kris Mahoney
Option 1.2.3 is a new herbicide alternative from Bayer CropScience for annual
grass and broadleaf weed control in field corn at the one to three leaf stage.
It competes with other herbicide programs like Battalion and Callisto + Primextra
II Magnum. However, when comparing all three programs, there are significant
differences in the level of weed control achieved on certain species.
Option 1.2.3 rates
Option 1.2.3 contains four components, two of which are included in one pre-pack.
The other two components (Aatrex 480 and 28 percent UAN) must be purchased separately
and then tank-mixed at the following rates:
- Option 2.25 OD (foramsulfuron): 270 mL/ac +
- Define 60 DF (flufenacet): 310g/ac +
- Aatrex 480: 710mL/ac 4. 28 percent UAN at 1.0L/ac.
Activity on weeds
Option 1.2.3 will control emerged and non-emerged weeds similar to Battalion.
Callisto + Primextra II Magnum will control emerged broadleaf weeds but only
emerged grasses up until the first to second leaf stage.
Strengths
Option 1.2.3 has good control of fall panicum, yellow foxtail, green foxtail
and velvetleaf (see Table 1).
| Table 1. Visual control of fall panicum, yellow foxtail and green foxtail six to eight weeks after herbicide application. |
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| Herbicide |
Percentage visual control (six to eight weeks after application) |
|||
| Fall panicum* | Yellow foxtail* | Freen foxtail* | Velvetleaf** | |
| Option 1.2.3 | 92 | 93 | 93 | 98 |
| Battalion | 81 | 88 | 85 | 81 |
| Callisto + Primextra | 45 | 99 | 99 | 100 |
| Sources: *Six comparative trials conducted by the University of Guelph in 2005 and 2006. **One comparative trial conducted by the University of Guelph in 2006. |
||||
Weaknesses
Option 1.2.3 does not adequately control large crabgrass (see Table 2).
| Table 2. Visual control of large crabgrass at six to eight weeks after herbicide application. |
|
| Herbicide | Percentage visual control – large crabgrass |
| Option 1.2.3 | 51 |
| Battalion | 66 |
| Callisto + Primextra | 100 |
| Source: Three comparative trials conducted by the University of Guelph in 2005 and 2006. |
|
Similarities
In public research trials, Option 1.2.3 effectively controlled a similar spectrum
of common broadleaf and grassy weeds as other comparable herbicide programs
like Battalion and Callisto + Primextra II Magnum. Effectively controlled: common
lamb's quarters, eastern black nightshade, pigweed species, wild mustard, wild
buckwheat, common ragweed and barnyard grass.
Perennial weeds
All three herbicide programs are generally not effective at controlling perennial
weeds. Although certain perennial weeds may be susceptible to components within
each of the three herbicide programs (Canada thistle and the Banvel II component
of Battalion), such perennial weeds have usually not emerged at the recommended
time of application.
Cost
When comparing the suggested retail price minus any 'automatic discounts', all
three herbicide programs are similarly priced at around $32 to $33 per acre.
Rebate programs were not considered since they are usually tied to volume purchases
or early pay periods which are not necessarily achievable by all growers.
Summary
When comparing Option 1.2.3 to similar products in public research trials, Option
1.2.3 demonstrated comparable control of many annual grassy and broadleaf weeds,
superior activity of fall panicum, and poor control of large crabgrass. Perennial
weeds should not be targetted with Option 1.2.3, Battalion, or Callisto + Primextra
II Magnum. -30-
