Annual and perennial weed control in pastures and hayfields is an important aspect of successful forage management. This publication will discuss control measures for many of the common weeds found in Virginia and West Virginia permanent fescue and mixed fescue / bluegrass / orchardgrass pastures and hayfields.

The Shenandoah Valley of Virginia and some other regions produce more manure nutrients than local crops need. This manure has traditionally been applied to row crops and overapplication has led to soil-test phosphorus (P) being well above agronomic optimum in many cases. In 2008, it was estimated that nutrient-management regulations now require that approximately 85 percent of poultry litter be applied off poultry farms, as they do not have sufficient land to beneficially recycle their manure nutrients. There is a substantial area of nutrient-deficient forage production in the Shenandoah Valley that could benefit from this poultry litter. This publication summarizes two years of field research on fertilizing nutrient-deficient forages with poultry or commercial fertilizer. It also evaluates split versus single annual applications of nutrients and addresses a common misconception that poultry litter contains weed seeds.

In Virginia, annual ryegrass has become one of the most troublesome and difficult to control weeds in small grains, as well as in corn and soybeans grown in rotation with small grains. Annual ryegrass control has declined due to the development of resistance to Hoelon, which has been the only treatment available for control in wheat and barley. Lack of control in small grains has allowed annual ryegrass to proliferate and become problematic in no-till corn establishment where high rates of triazine herbicides or sequential applications of nonselective herbicides are frequently required for acceptable control.

Common reed is a tall perennial grass with creeping rhizomes that may make a dense vegetative mat. The leaves are rolled in the shoot, no auricles are present, and the ligule is a fringe of hairs. Leaf blades are 1 to 5 cm wide, 20 to 60 cm long, flat, and glaborous. The leaf margins are rough and the sheaths are overlapping.

On October 3, 2007, the Weed Identification Clinic at Virginia Tech received an itchgrass [Rottboellia cochinchinensis (Lour.) Clayton] sample from a cornfield in Westmoreland County, near Montross (Figure 1). Currently, itchgrass is considered a federal noxious weed and the Westmoreland County sample is the first record of this plant in the state of Virginia.

There are thousands of species of moss worldwide. These very simple plants lack the typical leaf, shoot, root, and seed-forming systems of most higher plants; however, they are some of the hardiest living organisms on the planet (Figure 1). Lawn moss can reproduce sexually (spores, etc.) or asexually (breaking off into smaller pieces that divide and multiply), and their numbers can increase rapidly under the right conditions. They are tolerant of extremely low mowing, so regular clipping of the grass will not remove them. It would seem that these plants would not offer much resistance to our efforts to manage or control them, but as Mother Nature often shows, their simplicity in design and function correlates well with their ability to colonize and persist in some of the most inhospitable growing conditions around your property: sidewalks, driveways, and yes – the lawn.

Those who experience the blisters, swelling, and extreme itching that result from contact with poison ivy (Toxicodendron radicans), poison oak (Toxicodendron pubescens), or poison sumac (Toxicodendron vernix) learn to avoid these pesky plants. Although poison oak and poison sumac do grow in Virginia, poison ivy is by far the most common. This publication will help you identify poison ivy, recognize the symptoms of a poison ivy encounter, and control poison ivy around your home.

Palmer amaranth (Amaranthus palmeri), a member of the "pigweed" family, is one of the most troublesome weeds in many southern row crops. Seed can germinate all season and plants can grow to over 6 feet in height. Plants have either male flowers that shed pollen or female flowers that can produce up to 600,000 seed per plant. One Palmer amaranth per 30 foot of row can reduce cotton yield by 6 to 12%.

Palmer amaranth (Amaranthus palmeri), a member of the "pigweed" family, is one of the most troublesome weeds in many southern row crops. Seed can germinate all season and plants can grow to over 6 feet in height. Plants have either male flowers that shed pollen or female flowers that can produce up to 600,000 seed per plant. Four Palmer amaranth plants per 100 ft2 of row can reduce soybean yield by 12 to 17%.

Weeds constantly invade crop fields and pastures; therefore, it is important to know the potential quality of individual weed species in making management decisions concerning weed control. It is frequently assumed that weeds have low nutritive value and livestock will not eat weeds, so expensive and time-consuming measures are often used for their control.¹² Some weeds are toxic or poisonous to livestock, and certain weeds are unpalatable – causing a reduction in total intake.⁹ Several weed species have thorns or spines that can injure the grazing animal’s mouth and/or irritate its eyes, which may lead to pinkeye.⁹ Other weeds can cause the milk and meat of livestock to have a negative taste or odor. Weeds also compete with cultivated crops and forages for moisture, light, and nutrients, but many weeds are nutrient-rich and digestible.⁹ The objective of this review paper is to recognize the nutritional values of weeds commonly found in pastures.²

For small fruit growers, the challenge of weed management is one of the greatest they will face to successfully grow these crops. Factors such as climate, weed introductions and adaptability, and years of agricultural activity have come together to select for weed species that are aggressive and persistent. Without management, weeds compete with crops for light, nutrients and water, resulting in stressed plants, poor fruit quality and yield.

One question that I have frequently received this year, just like last year, concerns the availability of Surflan (common name oryzalin). Surflan is a commonly-applied preemergence herbicide for control of annual grasses like crabgrass and foxtail, along with certain annual broadleaf weeds like chickweed, pigweed, and lambsquarters.