With the drought, overgrazing of pastures this summer, and out of state hay being fed this winter, this all adds up to be the perfect environment for an extraordinary weed infestation in 2012. Identifying these weeds is the first step with control.
Let’s start by answering the question, what is a weed? Perhaps the best definition of a weed is a plant out of place, a plant that is growing where you don’t want it, this could be in a pasture, garden or lawn. Not all weeds are bad (just undesirable), like sunflowers in a corn field are considered weeds to a farmer, as is bermudagrass in a vegetable garden to the gardener.
Weeds can be grouped into two major categories, grasses and broad leaves. Weeds can compete with pasture grasses for water, nutrients and sunlight. They can also harbor insects and plant diseases. Some weeds are toxic and can cause livestock to become ill or die.
Weed seeds can remain dormant in the soil for many years, and then germinate when conditions are right. When weeds appear control can be achieved by many different methods. Prevention can be accomplished by planting weed free seed and/or by using a pre-emergent herbicide. In worst cases eradication of the invasive weed may mean complete reestablishment of the pasture. Non-reestablishment control methods may involve limited use of herbicides, cultivation, mowing or maintenance of a vigorous pasture grass that will crowd out weeds.
Mowing weeds with a rotary mower can be risky, it usually causes the weeds to produce their leaves closer to the soil. If you decide to mow, it should be done when weeds are in the bud or pre-bloom stage to reduce seed production of the invasive plant.
If a herbicide is used you must first identify the plant that is to be controlled to properly choose the right chemical. Herbicide application rates will vary by weed species and plant maturity. Some herbicides containing 2-4D as the active ingredient require a pesticide applicator license to purchase and apply. When using chemicals it is very important to read the label and follow the directions closely, to prevent injury to livestock or humans or damage from spray drift. Federal and State law controls the use of restricted and state-limited herbicides. General use herbicides do not require a license, such as Round-Up, Pasture Guard, Cimarron and Redeem and will do a good job on selected weed varieties.
Pasture weed control will increase forage production on the average of 1 pound for every pound of weeds controlled. This increase can be equivalent to the application of 40-60 pounds of nitrogen per acre. The best method of weed preventive control is to maintain a healthy and well fertilized stand of pasture grass.
Eddie Baggs, Denton County Extension Agent-Agriculture
Texas AgriLife Extension – Denton County
(940) 349-2880 or Metro (972) 434-8812
Educational programs conducted by the Texas AgriLife Extension serve people of all ages regardless of socioeconomic level, race, color, sex, religion, disability or national origin.