Trade name(s) Casoron, Barrier

Manufacturer(s) Chemtura, PBI/Gordon

Formulation(s) 50% wettable powder, 4% granules, 15.3% liquid

Remarks A nitrile compound used as a preemergent and early postemergent herbicide in noncrop areas and around established trees and shrubs. Dichlobenil is most effective when applied before weeds emerge, during cool weather, and immediately incorporated through irrigation or rain. It has little, if any, effect on foliage.

Water solubility 25 ppm

Storage conditions Store under cool, dry conditions to avoid volatility.

Acute toxicity LD50 - 5,000 mg/kg

Action in plant Inhibits meristematic tissue in growing points of roots and shoots.

Site of action Group 20: inhibits cell wall synthesis Site A

Chemical family Nitrile

Koc Average is 400 mL/g (estimated)

Vegetation Control

Tim Prather
Revised March 2016

Total vegetation control with soil-residual herbicides is a process in which the addition of chemicals renders the soil unfit for plant growth. Soil-residual herbicides do not kill all animal and microbiological life in the soil.

Keep the following in mind when using soil-residual herbicides:


Ed Peachey
Revised March 2016

Winter Applications to Dormant Rhubarb

carfentrazone (Aim EC)

Rate Up to 0.031 lb ai/A (2 fl oz/A Aim EC)

Time After crop emergence, but only to row middles. Use hooded and shielded sprayers.


Kim Patten
Revised March 2016

Preplant weed control All major weed problems can be prevented by starting with a clean field and avoiding reinfestation. For proper preplant management, growers should consider spraying perennial weeds with several applications of an appropriate systemic herbicide, using sand free from weed seeds, fumigating soil, planting weed-free vines, cleaning equipment when moving between beds, and seeding dikes with cover crops effective in preventing weed infestation (e.g., dwarf perennial ryegrasses and some creeping fescues).

Blueberries, Gooseberries, Currants, and Elderberries

Joe DeFrancesco and Ed Peachey
Revised March 2016

Weed Control Efficacy Ratings For information on weed control efficacy of products listed in this article, see the publication “Pest Management Strategic Plan for Blueberries in Oregon and Washington” (DeFrancesco and Murray, 2011): http://www.ipmcenters.org/pmsp/pdf/ORWABlueberry.pdf

Blackberries and Raspberries

Joe DeFrancesco
Revised March 2016

Boysenberry; Loganberry; blackberries (Marion, Evergreen and other cultivars);and red and black raspberries

Site Preparation

glyphosate (numerous product names)

Rate Consult labels

Vineyards and Grapes

Ed Peachey
Revised March 2016

(Note: Some clones may be sensitive to certain herbicides)

Weed and Vegetation Management

General strategy Vegetation management in vineyards is determined by site-specific environmental factors. Weed competition and interference must be minimized within the row while trafficability and soil conservation are required between rows (see “Section L. Vegetation Management in Orchards, Vineyards, and Berries” in this handbook).

Tree Fruits and Nuts

Ed Peachey
Revised June 2016

Pome fruits: apples and pears

Stone fruits: apricots, peaches, nectarines, cherries, prunes, plums

Nuts: hazelnuts, walnuts, and chestnuts

Site Preparation

glyphosate (numerous product names)

Rate Read label carefully for crops listed and geographic location.

Control of Problem Weeds

Timothy Prather, Timothy Miller, and Andrew Hulting
Revised June 2016

This section gives information about specific weeds that may be troublesome to control. Herbicides and/or rates listed cannot necessarily be used on cropland. Rates of application and restrictions vary depending on crop or site. Do not apply to a crop or site not listed on the label.

Non-cropland is greenspace where plants are not harvested by humans or animals for food, feed, or fiber; roadsides, for example.

Christmas Trees

Chal Landgren and Ed Peachey
Revised March 2016

Excessive weed growth in Christmas trees reduces tree vigor, increases vertebrate pests, and can reduce the quality of the product if plant debris is lodged among branches. However, completely eliminating all vegetation increases runoff, soil erosion, and soil compaction and can diminish tree quality if branches get muddy during harvest. Consequently, vegetation management in Christmas trees requires a balanced approach. Realizing that the goal is to produce quality trees while maintaing long-term site quality and managing—not just controlling—weeds.

Agrichemicals and Their Properties

Ed Peachey, Tim Miller, and Andy Hulting
Revised March 2016

This information provides specifications for users of this handbook. For more information regarding the physiological or biochemical activity and behavior in or on soils, refer to the Herbicide Handbook of the Weed Science Society of America.

Syndicate content