Use and Characteristics of Herbicides for Non-crop Weed Control PENN STATE Department of Horticulture - College of Agricultural Sciences Uses and Characteristics of Herbicides for Non-crop Weed Control Prepared by: Art Gover Department of Horticulture The Pennsylvania State University To the User of this Publication This document provides information about herbicides and their uses, primarily for use as a study guide for applicators seeking certification in Pennsylvania Categories 10 - Rights-of-Way, or 14 - Industrial Weed Control. This document does not provide instructions or directions for use. Directions for use for any pesticide product are contained only in the label. Do not use any pesticide without carefully reading the label. If information in this document is in conflict with the information in a product's label, then this document is in error, and the incorrect information must be disregarded (and hopefully brought to the attention of the author). To the best of the author's knowledge, the information in this document is current as of May, 2000. Although the intent is for this document to be exhaustive, there are surely products that have been omitted through ignorance - not intent. Inclusion or omission of a product in this document does not constitute a recommendation, or lack of a recommendation regarding the use of that product. Table of Contents Introduction .................................................................................................................................................1 Integrated Pest Management and Integrated Vegetation Management...........................................................1 Integrated Vegetation Management......................................................................................................1 IVM and Total Vegetation Control.......................................................................................................2 IVM and Selective Vegetation Management.........................................................................................3 Summary.............................................................................................................................................3 Herbicide Use Properties..............................................................................................................................4 Herbicide Formulations.......................................................................................................................4 Herbicide Application..........................................................................................................................5 Summary.............................................................................................................................................6 Herbicide Mode of Action............................................................................................................................7 Systemic vs. Contact Herbicides..........................................................................................................7 Categorizing Mode of Action...............................................................................................................7 Herbicide Resistance...................................................................................................................................11 Herbicides Available for Non-crop Use, by Product...................................................................................13 Herbicides Available for Non-crop Use, by Active Ingredient.....................................................................15 Summary of Herbicide Toxicity and Reaction to Inorganic Materials.........................................................18 Summary of Herbicide Behavior in Soils....................................................................................................19 Summary of Labeled Uses, by Product.......................................................................................................21 Individual Herbicide Summaries.................................................................................................................25 Introduction The term 'non-cropland' covers a wide range of Selective control is practiced in any non-crop settings - pretty much any area not supporting food, area where vegetative cover is desired. In some feed, fiber, forest, or nursery plantings. We can instances, the intent is to preserve vegetation that divide non-crop areas into those requiring non- was planted, such as turf along a limited-access selective control, and those requiring selective highway. The alternate scenario is an area where control. only certain vegetation is undesirable, and is selectively removed from the desirable, or non- Examples of areas where non-selective control, problem vegetation. An electric ROW is a common or total vegetation control is practiced include example of this, as trees that could grow to contact fencelines, highway guiderails, railroad ballast, the conductors are eliminated, while most shrubs, unpaved parking or storage areas, electric sub- and herbaceous plants are desirable. stations, petroleum tank farms, and the grounds surrounding industrial facilities. Regardless of the non-crop setting, the principles of Integrated Pest Management should Some of the reasons for practicing total be followed. vegetation control include ease of maintenance, ease of access, visibility, maintaining surface drainage, reducing fire hazard, and eliminating cover for vermin. Integrated Pest Management and Integrated Vegetation Management Integrated Pest Management (IPM) is a means A pest threshold is the level at which a pest to take a structured approach to common sense-, or becomes damaging enough to warrant control preventive pest control. IPM stresses using all efforts. In a commodity setting, this threshold is methods that are practically available, in a economic - it is the level where the yield loss coordinated, or integrated manner, to manage pests. caused by a pest is equal to the cost of controlling it. It does not make economic sense to implement a The stress is on the concept of management. control practice that costs more than the damage a Any ecosystem has many natural forces interacting pest is going to cause. in a constantly changing manner. IPM stresses encouraging or enhancing the natural forces that When pest thresholds have been set, scouting is work to our benefit, and trying as much as possible required to determine if pest levels are approaching to allow these natural processes to work in concert the threshold. Once a pest management effort has with our inputs. been made, it is necessary to monitor the pest population to determine if the control has been IPM brings together varied control methods, the successful. Keeping effective records of your notion of pest thresholds, scouting, monitoring, and scouting, control, and monitoring efforts provides record keeping. the information you need to anticipate pest Methods available to manage pests can be problems and gather the necessary resources in grouped into the following categories: advance. Cultural - methods that enhance the growth or Integrated Vegetation Management vigor of desirable species. Integrated Vegetation Management (IVM) is Mechanical - physical processes that exclude, simply adopting the IPM approach and targeting it damage, or remove pests. specifically at the management of troublesome Biological - using one organism to control vegetation. This is appropriate in rights-of-way and another. other non-crop sites because vegetation is typically Chemical - the use of pesticides. the only pest. The following section describes examples of control practices specific to vegetation management. Method Integration Cultural When used in a coordinated fashion, control methods are complementary. Cultural methods are practices to enhance the growth and vigor of desirable species. When the Mowing roadside turf high and infrequently desired species is more vigorous, it can withstand improves turf vigor, reducing weed pressure and the more pest pressure before there is a negative effect. need to use herbicides - judicious use of herbicides Some examples of cultural practices include proper controls established weeds, and therefore the seedbed preparation, adequate fertilization, and reduces the tendency to mow to 'clip' weeds, timely seeding of groundcovers; and increasing the reducing stress to the turf, which allows the turf to height and reducing the frequency of mowing of be more competitive - reducing weeds. utility turf. Treating brush selectively when it is small Mechanical reduces damage to adjacent desirable vegetation. The adjacent vegetation fills in, providing biological Mechanical controls physically remove, control so that brush cannot re-establish, which exclude, or harm target vegetation. Pulling, reduces the need chemically treat brush. mowing, cutting, or digging weeds are examples of mechanical methods. When large brush is mechanically treated, either by mowing, or cutting with a chain saw, following- Biological up with a cut-stubble or cut stump application reduces regrowth from the tree root systems. This Biological control is the use of other organisms allows the area to be re-established to desirable to control pest species. The leaf-feeding beetle vegetation, either naturally or by reseeding. The Galerucella has been introduced into North competition further inhibits regrowth of the brush. America to feed on the