Controlling weeds in alfalfa at the seedling stage is one of the most important factors in producing a high yielding, good quality stand of alfalfa. By competing for light, nutrients, and water, weeds can reduce yields and the value of alfalfa. If left unchecked, weed infestations can untimely render a stand of alfalfa worthless. Each of the four trials conducted, utilized combinations of herbicides. Herbicide combinations have several advantages over a single material application.
Herbicides have different modes of action and can be selective in the type of plants they affect.
Therefore, a combination of herbicides may control a broader range of weed species. Lower doses of two combined herbicides can usually be applied more efficiently than a higher dose of a single herbicide. Lower doses of herbicides reduce damage to the crop and lower the active residues left behind in the crop and soil, ultimately reducing environmental impacts. Lastly, combining herbicides greatly reduces the ability of weeds to develop resistance to treatments. A study performed by Orloff and Cudney, found that combination treatments of 2,4-DB amine plus Pursuit, Sethoxydin, or Pronamide, provided the most complete control of weed species.