Cattail Control in Corn

Chris Boerboom, Extension Weed Scientist

Last year’s wet summer brought a new weed to many corn fields this year – cattail. Controlling this new weed will be a challenge in some cases. Obviously, cattail will establish in wet or flooded portions of fields. If these areas dry enough for tillage, through tillage will probably be the best first step in effective control. Tillage should disrupt the cattail tubers and help with drying the soil, especially if the cattail are not well established. However, if the cattail is in a no-till field, it will be more difficult to control with herbicides. Few herbicides are labeled for cattail control, especially corn herbicides. Cattail is listed on most glyphosate labels. For instance, the Roundup PowerMax label recommends that 2 to 3.3 qt/a is applied at the early heading stage of growth. This timing increases the amount of glyphosate translocated to the tubers and increases control, similar to the practice with many other perennial weeds. Unfortunately, the maximum rate of PowerMax that can be used in corn with the Roundup Ready 2 trait is 32 oz/a (or 48 oz/a of a 3 lb ae/gal formulation). Also, the cattail will need to be sprayed before the heading stage. Despite these shortcomings, glyphosate may be one of the most effective options to suppress in no-till corn. I would recommend using the highest labeled rate and delay the application as long as reasonable.  As a tank mix partner, dicamba may increase the activity of glyphosate in glyphosate-resistant corn (see conventional corn comments for more information).

In Liberty Link corn, I don’t have experience, but I doubt that Ignite will be effective in Liberty Link corn because Ignite is primarily a contact (non-translocating) herbicide. 

In conventional corn, the best suppression options might include dicamba-based herbicides (e.g. Banvel, Clarity, Status). Initially, you might wonder if this “broadleaf” herbicide would work on this “grass-like” plant. It is true that cattail is a monocot and not a dicot plant. However, cattail is in the Typhaceae (cattail) family, not the grass family. Just as Permit is a broadleaf herbicide, is not active on grasses, but highly effective on the monocot, yellow nutsedge. Dicamba is active on cattail. Again, the low labeled rates allowed and early timing of dicamba applications will likely limit the amount of control achieved. Others have suggested that dicamba activity might be increased if tank mixed with an ALS-inhibiting herbicide (such as Steadfast), but this is speculation. 2,4-D is not rated to be as effective as dicamba or glyphosate.

Growers will have to wait to control cattail in areas of fields with standing water (photos 1 and 2). If these potholes dry during the summer, a high rate of glyphosate could be applied at the proper stage mentioned above. 

 Cattail facts

• Broadleaf cattail (Typha latifolia) is a native plant, but narrowleaf cattail was introduced. Both narrowleaf cattail and the hybrid of these two cattails are considered unwanted invasive weeds.
• Cattails reproduce by seed and tubers, but rapid spread is through wind-borne seed.
• Cattails can produce 20,000 to 700,000 seeds per flowering “spike”.
• Cattail seed readily germinates to start new seedlings or seed can persist in the soil for long periods of time if conditions are not proper for germination. 

 Photo 1. A 2-year old (?) patch of cattail established in a corn field.

Photo 2. Close-up of cattail (8-16 inches tall) in mid-May in a corn field.