PB1521 Hay Crop and Pasture Weed Management

Hay crops and pastures are essential, highly valuable resources for Tennessee's beef cattle and dairy industries. Many ingredients must come together to insure optimum yields of high quality forage for beef and dairy animals. One of the key ingredients is a well-planned and well-executed weed management plan. Fortunately, compared to many agronomic and horticultural crops, forages are more competitive with weeds, so the likelihood of weed problems requiring yearly herbicide applications is lower.

Why, then, do weeds become troublesome in forage crops? Weeds can become troublesome because most grow rapidly, and many are prolific seed producers. Many of the seed produced can remain dormant for years. For example, research has shown that musk thistle, curly dock and pigweed can produce as many as 10,000, 40,000 and 120,000 seed, respectively, per plant in one growing season. Ultimately, weeds become troublesome in hay crops and pastures because they find room to grow. This room to grow may be due to a thin stand because of low seeding rate, poor internal drainage of the soil, droughty soils, low pH and/or poor fertility status or overgrazing.

Whether it is permanent grass pasture, alfalfa or other legumes, a bermudagrass hay field or sorghum-sudangrass hybrids, management of the crop for maximum competition is the first and most effective weed management input. In practically all cases, it is also the least expensive.