Item D Number 03519 G Not Scanned Author Romancier, Robert M. CorpOratB Author Georgia Forest Research Council Report/Article TitlB 2'4'D' 2.4'5-T> and Related Chemicals for Woody Plant Control in the Southeastern United States Journal/Book Title Year Month/Day Color D Number of Images 46 Descrlpton Notes Monday, December 31, 2001 Page 3619 of 3802 2, 4-D, 2, 4, 5-T, AND RELATED CHEMICALS FOR WOODY PLANT CONTROL IN THE SOUTHEASTERN UNITED STATES BY ROBERT M. ROMANCIER REPORT NUMBER 16 GEORGIA FOREST RESEARCH COUNCIL MACON, GEORGIA 1965 2, 4-D, 2, 4, 5-T, AND RELATED CHEMICALS FOR WOODY PLANT CONTROL IN THE SOUTHEASTERN UNITED STATES BY ROBERT M. ROMANCIER SOUTHEASTERN FOREST EXPERIMENT STATION FOREST SERVICE, U.S. DEPARTMENT OF AGRICULTURE ASHEVILLE, NORTH CAROLINA REPORT NUMBER 16 GEORGIA FOREST RESEARCH COUNCIL MACON, GEORGIA 1965 THE AUTHOR: Robert M. Romancier, a native of Springfield, Massa- chusetts, has degrees in forestry from the University of Massachusetts and Yale University. Since joining the U. S. Forest Service in 1957, he has served at field locations maintained by the Southeastern Forest Ex- periment Station at Franklin, Virginia, Macon, Georgia, and Charleston, South Carolina. At these centers, Roman- cier worked primarily in forest management research, especially on problems of pine regeneration and also the uses of fire and chemicals in hardwood control. Early in 1965 Romancier moved to Station headquarters in Asheville, North Carolina, where he is serving as a staff assistant in the Timber Management Research Office. THE COVER: Georgia Forestry Commission photo. The use of tractor-mounted mist blowers is one of the latest and most popular techniques in the application of herbicides for woody plant control in the Southeastern United States. TABLE OF CONTENTS ~ - - 5 ~ ~ 5 THE PROBLEM AND THE ROLE OF 2,4-D AND 2,4,5-T 7 THE GENERAL NATURE AND ACTION OF 2,4-D AND 2,4,5-T 7 PENETRATION AND ABSORPTION _ 8 TRANSLOCATION - - 8 DEATH — - 9 STRUCTURE AND FORMULATIONS OF 2,4-D, 2,4,5-T, AND RELATED COMPOUNDS 10 STRUCTURE 10 2,4-D . __ -..- 10 2,4,5-T 10 OTHERS 10 2-(2,4,5-TP) 10 2-(2,4-DP) ._ 10 4-(2,4-DB) 10 TORDON „ - -.- - 10 ADDITIONAL HERBICIDES 10 FORMULATIONS - 11 ACID ... ... 11 SIMPLE SALTS 11 AMINE SALTS 11 ESTERS 11 CARRIERS, ADDITIVES, AND CONCENTRATIONS 12 CARRIERS - 12 WATER 12 OIL-WATER _ 12 OIL 13 ADDITIVES 13 CONCENTRATIONS 13 APPLICATION 14 METHODS 14 BROADCAST TREATMENT ._ 14 HIGH VOLUME SPRA YING 14 AERIAL SPRAYING 15 MIST BLOWING 16 INDIVIDUAL STEM TREATMENT 17 INJECTION -- 17 FRILLING - - - 18 BASAL SPRAYING 18 SOIL TREATMENTS 20 COMBINATION TREATMENTS _ 20 EFFECTIVENESS OF THE PHENOXY HERBICIDES 20 2,4-D 20 ACIDS 20 SIMPLE SALTS _ 20 AMINES 20 ESTERS 21 2,4,5-T .- 21 ACIDS 21 SIMPLE SALTS 21 AMINES 21 ESTERS 21 OTHERS _ 22 2-(2,4,5-TP) 22 2-(2,4-DP) 22 4-(2,4-DB) 22 TORDON - 22 CHOOSING THE MOST SUITABLE CHEMICAL, FORMULATION, AND METHOD 23 DRIFT _ 23 DROPLET SIZE AND DISTRIBUTION 23 SPECIES 23 HARDWOODS _ 24 CONIFERS 24 TIME OF YEAR .... 26 TREE SIZE AND CONDITION 26 STAND STRUCTURE 26 ENVIRONMENTAL FACTORS 26 SOIL MOISTURE AND SITE CONDITIONS . 26 WEATHER 26 LIGHT 27 OTHER FACTORS 27 COST 27 SOIL MICROORGANISMS AND RESIDUES ..- 28 POSSIBLE HARMFUL EFFECTS 28 MAN 28 ANIMALS 28 EVALUA TION CONSIDERA TIONS 29 GENERAL RECOMMENDATIONS 30 HIGH VOLUME SPRAYING 30 AERIAL SPRAYING 30 MIST BLOWING 30 INJECTION 30 FRILLING 30 BASAL SPRAYING 31 APPENDIX 32 STRUCTURAL DIAGRAMS 32 CARE OF EQUIPMENT 33 COMMON AND SCIENTIFIC NAMES 33 LITERATURE CITED 35 GLOSSARY 44 BIBLIOGRAPHY 45 FOREWORD This paper is intended to serve as a source of reference and as a guide to foresters and landowners who want information about 2,4-D, 2,4,5-T, and certain related chemicals. The scope is primarily limited to these herbicides as they relate to control of woody plants growing in the southeastern United States. Properly used, these recently syn- thesized herbicides will control many of the woody plant species found in the southeast, at reasonable costs, and with far greater safety than some of the earlier chemicals. ACKNOWLEDGMENTS Many people have assisted in the preparation of this paper. I wish especially to thank 0. Gordon Langdon of the Southeastern Forest Experiment Station for his many useful suggestions and hours of discussion, and also E. V. Brender of the same Station who made many contributions in the early phases of this publication. Several re- viewers gave sound advice: W. E. McQuillan of the Northeastern Forest Experiment Station, John L. Arend of the Lake States Forest Experiment Station, Jack Stubbs of the Southeastern Station, and John H. Kirch of Amchem Pro- ducts, Inc. Mason C. Carter, Auburn University, was especially helpful with the sections on organic chemistry. 2, 4-D, 2, 4, 5-T, AND RELATED CHEMICALS FOR WOODY PLANT CONTROL IN THE SOUTHEASTERN UNITED STATES BY ROBERT M. ROMANCIER THE PROBLEM AND THE ROLE OF THE GENERAL NATURE AND 2,4-D AND 2,4,5-T ACTION OF 2,4-D AND 2,4,5-T The control of weeds has been a problem ever These chemicals are in the organic chlorophenoxy since man first learned to cultivate plants. Some weeds (or simply phenoxy) group. They are nonflammable, non- compete with desirable plants for space, water, or nu- explosive, and noncorrosive. They are considered selec- trients; others poison man's livestock, irritate allergies, tive, in that some plants are more susceptible than others spread plant diseases, or in other ways interfere with to these substances. And they are translocated herbicides, the most effective utilization of this productive earth. which means they travel within the plant, rather than Weed control measures are often among the most acting only where they are applied. They are usually expensive steps in growing crops for food or fiber. In effective in very low concentrations. the never ending struggle against weeds, man has used 2,4-D and 2,4,5-T are auxins or growth regu- many methods of control. He has used his bare hands lators which in some ways act like plant hormones (43, to pull weeds out of the ground, he has used a hoe or 143), but they disrupt the normal cell and plant life fashioned many mechanical tools to act as hoes, he has processes. Unfortunately, much of the basic research used fire, he has introduced insect enemies of plants, into the action of the phenoxy herbicides has not been on he has encouraged domestic animals to eat the weeds, he the woody plant group, but rather on tomatoes, beans, has flooded with water. And he has used chemicals. oats, and morning glories, so it is often risky to apply Chemicals are not new to the field of plant control, the findings of such studies to maples, pines, or oaks. for we know salt was used to sterilize fields in Biblical Additionally, almost every study has been based on foliar days. In more recent times, sodium arsenite and am- application, with little attention given to cut surface, monium sulfamate (ammate) have been used to kill dormant season, or soil application. woody plants, but the arsenite is dangerous, most forms Certain conditions and observations, however, are of ammonium sulfamate are corrosive to metal, and basic to all plants. Thus, some references cited here are neither is selective—they kill or affect whatever they based on nonwoody plants, such as oats, or unfamiliar contact. There has been a definite need for a selective, tree species, such as California blue oak, rather than on low-cost herbicide. woody weed species found in southeastern forests. Two chemicals, 2,4-D and 2,4,5-T, were first syn- There are many obstacles or variables affecting thesized in the early 1940's (167). The first developed, the performance of a translocated herbicide. Shaw et al. 2,4-D (2,4-dichlorophenoxyacetic acid), was initially (188) graphically illustrated some of these obstacles in found to be a plant growth regulator (235). The de- the following diagram (Figure 1). Freed (63) has esti- velopment of 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) mated that less than 40 percent of the applied chemical followed closely. In 1944, after successful field trials, finds its way into the plant to become effective. Hamner and Tukey (73) announced that 2,4-D and For a translocated herbicide to have a potentially 2,4,5-T were selective herbicides.1 Wartime secrecy had lethal effect on a plant: (1) the herbicide must penetrate been imposed when it was thought that these herbicides or be absorbed into the plant, (2) it must move through might be used to kill enemy crops. A more complete ac- the plant, generally in the phloem, and (3) it must have count of the discovery of 2,4-D and 2,4,5-T and their a toxic reaction with the cells and tissues of the plant uses has been written by Freed (63). (29, 108). Since 1944, continuous advances in chemical for- mulations, knowledge of the specific action or actions 'Some confusion in terms exists. Properly, an of these herbicides, and new application methods and herbicide will kill herbs—plants that annually die back to equipment have been made. Preparations and techniques the ground and have no woody stem. Silvicides and ar- of the 1940's and 1950's have been superseded, and boricides kill tree species, and phytocides kill all plant results have been bettered.