Mark VanGessel, Extension Weed Specialist; firstname.lastname@example.org
This appears to be the year for yellow nutsedge and horsenettle. Only a few products will provide yellow nutsedge control in corn. Glyphosate products are rated as suppressing yellow nutsedge if applied up to 6 inch tall plants. A recently registered product for our region, Permit Plus at 0.75 oz wt/A, is the best product available. Permit Plus contains halosulfuron and thifensulfuron (active ingredients in Sandea and Harmony). Permit Plus can be tankmixed with glyphosate. Basagran will control emerged tissue of yellow nutsedge, but the plants often regrow from the nutlets. Other products list nutsedge suppression but need to be applied to very small nutsedge plants. For soybeans, Basagran and glyphosate are also available, but so is Classic, for nutsedge plants up to 4 inches tall. Classic can be tankmixed with glyphosate.
Nutsedge control in vegetables includes Basagran or Sandea. Later planted vegetables can be treated at planting with Dual and/or Pursuit for control/suppression of yellow nutsedge. Pre-plant incorporated applications of Dual generally provide better yellow nutsedge control than applications to the soil surface.
Horsenettle is a perennial that emerges from creeping rhizomes and is hard to control. Glyphosate is rated as fair for control of horsenettle, but no other soybean herbicide provides control or appears to enhance glyphosate activity. In corn, Callisto provides good horsenettle control. Banvel, or dicamba containing herbicides, provide fair control of horsenettle. Postemergence options in vegetables are very limited; most products will provide some leaf burn but poor control.
Both yellow nutsedge and horsenettle should be treated after harvest with glyphosate. In late summer or fall, these plants are moving sugars to their root systems where the glyphosate can kill the perennial tissue of the plants.