Share

Pests

Weed Management

Managing weeds in forages requires a different approach than weed management in row crops.

Without proper management, broadleaved weeds can directly compete with forage grasses or pasture to reduce its nutritional value and longevity.

The weed multiflora rose (Rosa multiflora, Thunb.) is an increasing problem in Pennsylvania pastures and noncropland. It thrives on idle land, fencerows, and minimally maintained, hilly pastures.

Alfalfa (Medicago sativa) is an important perennial forage crop used around the world. Alfalfa is the fourth largest crop, in terms of acreage, grown in the United States behind corn, soybeans, and wheat.

This publication will discuss weed management options for Conservation Reserve Enhancement Program (CREP) grassland acres enrolled in Conservation Practices CP1, CP2, and CP10. Areas designated otherwise (e.g., CP22, riparian buffers) are not discussed in this publication.

Insect Management

Management of forage insect pests is aimed primarily at the alfalfa weevil and the potato leafhopper in alfalfa.

The clover root curculio is a common insect in Pennsylvania alfalfa and clover fields. It is believed to be of European origin, and was originally reported from North America in New Jersey in 1875.

Two insect pests, the clover root curculio and the clover root borer, are partially responsible for the reduction or elimination of red clover stands.

The potato leafhopper is the most destructive insect to alfalfa in Pennsylvania, causing average annual losses of approximately $15 million. It reduces yields, quality (especially lower protein content), and stand longevity.

The first arrivals of adult Potato Leafhoppers (PLH) will have made it into PA in June from their wintering areas in the Southeastern United States.

The potato leafhopper (PLH) is the number one pest affecting alfalfa. This tiny (1/8 inch) wedge shaped, pale yellowish-green, winged insect can significantly affect alfalfa yields and forage quality.

If you were a Cereal Rust Mite, the most widespread source of decreased timothy forage yields in south central Pennsylvania, you would be pretty darn happy right about the time you are reading this article.

Researchers note that alfalfa weevils have a long egg laying and hatching period.

Disease Management

The following management practices will help minimize disease losses in alfalfa.

PDF, 10.5 MB

Forage grasses are subject to a multitude of leaf, stem, floral, and root diseases. The leaf diseases include rusts, smuts, and leafspots, and cause the major reductions in yields, as harvested forage consists primarily of leaf material. Grass diseases may limit effective utilization of the grass species and affect herbage quality, digestibility, tillering, and root growth.

Forage grasses are subject to a multitude of leaf, stem, floral, and root diseases. The leaf diseases include rusts, smuts, and leafspots, and cause the major reductions in yields, as harvested forage consists primarily of leaf material. Grass diseases may limit effective utilization of the grass species and affect herbage quality, digestibility, tillering, and root growth.