Weed control also is very important while the forage is young and prone to competition from invading species. The effectiveness of various herbicides at or during establishment is listed in Table 8-10 . Herbicides available for use during the establishment year are listed in Table 8-11 . The best weed control in an established forage stand is achieved by maintaining a dense healthy stand through proper fertilization, cutting management, and insect control. Controlling weeds in established forages normally is of greatest benefit in the first cutting.
Weeds generally contribute much less to yield in the second and succeeding harvests.
Before using a herbicide in established stands, evaluate the forage to ensure that it is worth the cost of the herbicide. Be sure that there are sufficient desirable species to fill in the gaps. A minimum of five alfalfa plants per square foot should be present. Weeds tolerant of the herbicide may invade the space left by susceptible species, ultimately creating a more severe weed problem. Only well-established vigorous stands should be treated with herbicides.