There are many products on the market that will do a fine job of controlling broadleaf weeds. Probably the most well know product is 2,4-D. It gives excellent control of bitter sneeze weed, plantains, buttercup, and ragweed but relatively poor control of horsenettle and most woody weeds. One note here on 2,4-D. When applied at lower rates, it will not harm white clover. Cimmaron is widely used. This product is excellent on bahiagrass, curly dock, buttercup, wild garlic, and spiny amaranth. However, it only injures ryegrass and is poor on horsenettle. Weedmaster provides excellent control of broadleaf weeds and is the preferred product in hay operations. Try to choose a product that will control as many of the weeds that you have as possible. This will keep costs down and avoid multiple trips through the field. If more than one product must be used, try to choose products that can be mixed in the same tank and applied in one pass. Some products, like Weedmaster, can be mixed with liquid fertilizer as the carrier. Using this method, a producer could perform two functions with one pass. Also note the surrounding crops. Many of these herbicides are lethal to cotton, tobacco, and soybeans. Producers should choose a product that won’t harm surrounding crops if exposed to drift. If this is not possible, try to choose a formulation that is less prone to volatilization. The more volatile a product is, the more likely you will experience product drift. Drift will also vary with boom height, nozzle type, pressure, and wind. Remedy, Crossbow, and Redeem R&P are all labeled for hay and pasture but must be used cautiously due drift dangers. Grazon P&D is probably the best and most dangerous product available. The product has seen drift up to 2000 feet.
Producers should know and adhere to any grazing or haying restrictions. Some products have restrictions on grazing and haying. Others have restrictions just on haying. These restrictions can be anywhere from seven days to one year so make sure you know what you are dealing with. An interesting note here is that most products that have no grazing restrictions for beef cattle will have grazing restrictions for dairy cattle. Most will also have a withdrawal period before slaughter.
Controlling grass weeds in pastures and hay fields in much more challenging. Most products on the market give minimal control on most grasses. Cimmaron will control bahiagrass along with certain broadleaf weeds. The ester formulation of 2,4-D will control crabgrass in newly sprigged bermudagrass for approximately three weeks. Roundup Ultra can be used to control crabgrass and sandbur if used immediately after the first cutting. Gramoxone Extra can be used to kill winter annuals in dormant bermudagrass and is safer on greening-up bermudagrass than Roundup. For control during the summer growing season, the options available are Journey, Panoramic, and Pastora.
Journey and Panoramic are labeled for use in bermudagrass for the control or suppression of many grass weeds. These weeds include crabgrass, nutsedge, sandbur, Johnsongrass, vaseygrass, barnyardgrass, and others. They will cause some stunting of the bermudagrass, especially if used at high rates. For this reason, they should not be used until the bermudagrass has reached full green-up and no more than 6 ounces per acre of the active ingredient, imzapic, should be applied regardless of the weed species you are trying to control. At this rate you will see minimal and acceptable levels of suppression to the bermudagrass. If more than 6 ounces are used be prepared for severe, very noticeable suppression of the bermudagrass crop. Also note that these herbicides have a lenghty restriction on overseeding rye. This will limit the use of these two products on sprayfields that will be overseeded. In these cases control of problem grasses can come from the use of spot treating with Roundup, application of Roundup with a wicking device, or Pastora.
Pastora is new to the market, having received EPA clearance this year. Patora is labeled for bermudagrass pastures and hay fields and has no grazing or haying restrictions. Moreover, it will not cause stunting of bermudagrass like Journey or Panoramic. Pastora will control twenty-five different grass weeds and over 100 different broadleaf weeds.