One-Pass Considerations
A soil-applied application of either Keystone®, Keystone LA, FulTime®, Surpass® or TopNotch® herbicide should be the foundation of any weed control program in conventional corn. Eliminating early season competition for your emerging corn from grasses and broadleaf weeds with a soil-applied product is an important first step toward realizing yield potential.
- Experiments conducted by University of Guelph professor Charles Swanton found that corn can “see” the color of light, and can determine if weeds are nearby. He says this helps explain how early season weed control can help improve yields up to 20 percent.1
- South Dakota State University weed scientist Sharon Clay reports less yield loss is experienced when weeds emerge after the V2 to V3 stages, adding that in some years it takes just five plants per square yard emerging with the crop to reduce yields as much as 10 percent.2
Can you get complete weed control with just one pass? Or is a two-pass program necessary?
Following are guidelines to help determine whether grasses and weeds can be controlled with a broad-spectrum, one-pass tank mix of Keystone + Hornet® WDG herbicide.
- Soil-applied herbicides have a greater availability in fields with coarse- to medium-textured soils and are more likely to effectively control weeds.
- Fields with organic-matter content of 4 percent or less allow more of the herbicide to be available for weed control.
- Use a one-pass approach with light to moderate weed infestations, so long as those fields typically don’t experience late emergence of troublesome weeds, such as ragweeds, waterhemp, cocklebur or Canada thistle.
Following are examples of one- and two-pass programs in conventional corn.
| Examples of One-Pass Programs† |
| Timing |
Herbicides |
| Pre to Early Post |
Keystone (2.2 to 3.4 qts.) + Hornet® WDG (3 to 4 oz.) |
| Pre to Early Post |
Keystone (2.2 to 3.4 qts.) + Python® (0.8 to 1.0 oz.) |
| Pre to Early Post |
FulTime (2.5 to 4.0 qts.) + Hornet (3 to 4 oz.) |
| Pre to Early Post |
FulTime (2.5 to 4.0 qts.) + Python (0.8 to 1.0 oz.) |
†Rates vary based upon soil pH values and organic matter content.
1www.tristateneighbor.com/articles/2004/12/12/tri_state_news/production_news/news19.txt
2Made in the Shade: Weeds Find Growing Tough in Crop Canopy. Iowa Farmer Today, April 9, 2005.
Keystone, Keystone LA, Surpass, FulTime and TopNotch are Restricted Use Pesticides and are not available for sale, distribution or use in the state of New York. Hornet WDG is not available for sale, distribution or use in Nassau and Suffolk counties in the state of New York. Always read and follow label directions.
