This publication discusses a number of options that are available to the greenhouse manager for controlling weeds such as creeping woodsorrel, hairy bittercress, spotted spurge, and others. Not only are these persistent problems in greenhouses but they detract from the perceived quality of plants produced, and also are known to harbor insects, such as whitefly and thrips, and other pests such as mites, slugs and snails.
This pesticide factsheet covers the use and characteristics of Princep, Simazine (simazine).
This pesticide factsheet covers the use and characteristics of HGH 75 (oxyfluorfen + trifluralin).
This pesticide factsheet covers the use and characteristics of Regal O-O (oxyfluorfen + oxadiazon).
This pesticide factsheet covers the use and characteristics of Dimension (dithiopyr).
This pesticide factsheet covers the use and characteristics of Pennant Magnum (S-metolachlor).
This pesticide factsheet covers the use and characteristics of Tower (dimethenamid-p).
This publication covers weed management practices for cotton production.
This pesticide factsheet covers the use and characteristics of Broadstar (flumioxazin).
This pesticide factsheet covers the use and characteristics of Pendulum, Aquacap, Corral (pendimethalin).
This pesticide factsheet covers the use and characteristics of Casoron (dichlobenil).
This pesticide factsheet covers the use and characteristics of Ornamental Herbicide II (oxyfluorfen + pendimethalin).
This pesticide factsheet covers the use and characteristics of the preemergence herbicide: Barricade, Prodiamine or Regalkade G (prodiamine).
This pesticide factsheet covers the use and characteristics of Marengo (indaziflam).
This chapter of the North Carolina Organic Grain Production Guide discusses cultural, mechanical and chemical tactics used for weed control in organic farming.
For organic soybean producers increased seeding rates improve early soybean canopy density, which shades out weeds in the early stages of weed competition. Organic soybean producers can increase seeding rates with much less of a negative impact on economic return than for conventional production with herbicides.
Organic farmers cite weed management as their number one research priority. This publication in the Organic Production publication series describes weed control strategies for organic farms based on weed characteristics and an integrated cropping system approach. A special section on cultivation practices that limit emerged and future weeds is based on research by the Center for Environmental Farming Systems.
Keeping weeds out early in the season is very important for cole crops that are marketed by size. Learn how to use both cultivation and herbicides to achieve good early-season weed control and avoid losses in yield and profits.
Cool-season leafy greens face a different weed spectrum than warm-season crops. The presence of weeds in harvested greens can result in lower prices or rejection at market. Learn about the cultivation and herbicide options that growers can use to avoid weed competition and contamination.
Weed competition in lettuce reduces both yield and head quality. This cool-season crop faces competition from winter annuals as well as early summer weeds. Learn about the cultivation and herbicide options that growers can use to control weeds in lettuce, including advice for lettuce grown with plastic mulch.
Being related to cotton, okra can be a poor competitor with weeds, particularly early in the growing season. As the crop is harvested, more sunlight can reach the soil and increase late-season weed interference. Learn about the cultivation options and herbicides that growers can use for weed control in okra.
Most commercial onions produced in North Carolina are seeded in the fall and harvested in mid- to late-June. Weed competition can reduce onion yields up to 96 percent, and weeds must be controlled throughout the growing season. Learn about the cultivation and herbicide options growers can use to keep onions weed-free in both wide and narrow rows.
Establishing and maintaining quality annual color beds requires a plan to prevent and control weeds. Weeds compete with ornamental plants for water, light, and nutrients, reducing aesthetic quality and plant growth. To minimize these problems, this publication presents a weed management program that should be developed and implemented prior to planting.
Growing strawberries as an annual crop on black plastic requires a different weed management strategy than the perennial matted row strawberries. When black plastic is combined with fumigation by methyl bromide, excellent control of most weeds in the row can be expected. However, weeds that have hard seed coats, such as vetch and clover, emerge for long periods of time and can establish in the row. They emerge in late fall or spring, grow under the plastic for a period of time, and emerge from any holes in the plastic.
The objective of this leaflet is to discuss weed-control considerations and herbicide options for grape vineyards in the Southeastern United States. It should be used as a guide for growers making vineyard floor management decisions. It should not be used as an alternative to a pesticide label.
Japanese stiltgrass (also known as annual jewgrass, bamboograss, flexible sesagrass, Japanese grass, Mary's grass, microstegium, Nepal microstegium, or Vietnamese grass) is a summer annual commonly found in shady, moist areas and is spreading rapidly in woodlands as well as shaded landscapes and low-maintenance turf throughout the southeastern United States and mid-Atlantic states. Japanese stiltgrass germinates in early spring, several weeks before crabgrass, yet flowers and seeds much later, from mid-September through October. It has broader, shorter leaves than many other annual grasses; somewhat resembling broadleaf signalgrass or spreading dayflower. After frost, the foliage and wiry stems turn a distinctive light tan in color and persist through the winter. Vegetative identification characteristics include: rolled vernation, a very short membranous ligule, and leaf blades that are shorter and broader than most other grasses.
Weeds compete with conifer seedlings for light, water, nutrients and space. Of these, light competition is probably the most detrimental to conifer seedlings. Shading will reduce growth, and generally weaken seedlings making them more susceptible to insects, mites and diseases. Weed competition has also been known to reduce winter hardiness. Consequently, an intensive weed control program is required to produce quality seedlings and transplants.
More than 40 sedge species may be found in North Carolina landscapes. Although grass-like in many ways, and the nutsedges are often referred to as “nutgrass”, they are not grasses and require different control measures than grasses. Sedges are easily distinguished from grasses by their leafy shoots that produce leaves in “3s” resulting in stems that are triangular in cross section. In contrast, shoots of grasses are flat or round in cross section.
Manual removal of weeds is time consuming, expensive, and often results in damage to landscape plants when intertwined roots of both the weed and the ornamental plant are pulled up. Nonselective herbicides (which must be selectively applied to avoid injury to desirable plants) are typically used for postemergence annual and perennial weed control. This publication covers choosing the right herbicide for this situation.
The use of wildflowers in the landscape has increased since Lady Bird Johnson first promoted them in the late 1960s and early 1970s. Wildflowers were further popularized by the "Meadow in a Can" seed collections that were marketed in the early 1980s. A number of books have been written that describe methods for planning and planting wildflowers, however, few recommendations are available regarding maintenance and long-term weed management. In wildflower plantings, weed management is a complex system that requires knowledge of the specific wildflowers and weeds, environmental conditions, and control methods. Therefore, the objective of this leaflet is to discuss weed management strategies that can be applied to the planning, establishment, maintenance and renovation stages of a naturalized wildflower planting.