What is in this article?:
- Barnyardgrass - what's your plan?
- What you can do
- Start clean.
- Use an at-planting application of a residual herbicide.
- Over-the-top programs should contain tank-mixtures of postemergence and residual herbicides with multiple modes of action.
- Regardless of the herbicide mixture, timing is critical.
- Strive for 100 percent control before flood.
What you can do
Following are some suggestions for barnyardgrass control in rice.
Start clean. This cannot be over-rated as a control tactic. In my rice plots at Stoneville, Miss., in 2010, we sprayed glyphosate at planting to control emerged barnyardgrass. This application worked poorly, and we never got back ahead of the barnyardgrass. Make sure fields are free of barnyardgrass before rice begins to emerge. This is a critical first step in successful barnyardgrass control.
Use an at-planting application of a residual herbicide. Like Palmer amaranth in row crops, barnyardgrass is much easier to control before it comes out of the ground. An at-planting application of Command will reduce early-season competition and also increase the effectiveness of postemergence treatments because these will be targeting smaller barnyardgrass plants.
Over-the-top programs should contain tank-mixtures of postemergence and residual herbicides with multiple modes of action. For example, the first over-the-top application could include propanil plus Bolero (or RiceBeaux) or quinclorac. Ricestar HT plus quinclorac or Prowl H2O would be an alternative in areas with propanil-resistant barnyardgrass. Tank mixtures containing different modes of action are also important to reduce the selection pressure on the limited chemistries available in rice that are active against barnyardgrass.
Regardless of the herbicide mixture, timing is critical. Well-timed, early-season applications always provide the most consistent control. Too often, barnyardgrass is sprayed in the three- to four-leaf stage (or tillering) rather than the one- to two-leaf stage. This can be a recipe for failure. Barnyardgrass cannot be sprayed too early. Control barnyardgrass when it is at a manageable size and rely on the residual herbicide in the tank mixture for control of the next flush.
Strive for 100 percent control before flood. Clincher has been used extensively as a postflood treatment in rice. Postflood, salvage-type applications can be important because there is always barnyardgrass that survives preflood herbicides. However, Clincher should be utilized to control barnyardgrass escapes. It should not be relied upon to control dense populations of barnyardgrass that have the luxury of ample water and fertilizer that will help it withstand the Clincher treatment.
My best advice for barnyardgrass is “have a plan.” Do not wait for barnyardgrass to emerge to decide how you will control it in rice. Use all the tools available, i.e., effective burndown, residual herbicides, well-timed postemergence application, tank mixtures and the flood. Hopefully, by utilizing all these tactics, the effectiveness of our barnyardgrass herbicide arsenal can be sustained into the future.