Document V3jGLvgy7gMkv9E63w1Gpgbzg

X'~ F i i Il i ! ! \ Reproduction of this publication in vhole or in part is prohibited except with permission of the Commanding Officer, Fort Detrick, ATIN: Technical Releases Branch, Technical Information Division, Fort Detrick, Frederick, Maryland, 21701. However, DDC is authorised to reproduce the publication for United States Government purposes. DDC AVAILABILITY NOTICES Qualified, requesters say obtain copies of this publication from DDC. Foreign announcement and dissemination of this publication by DDC is not authorized. DISPOSITION INSTRUCTIONS When this publication is no longer needed, Department of Army organisations will destroy it in accordance with applicable directives. Department of Defense contractors vil] destroy the publica tion according to the requirements of Section 14 of the Industrial Security Manual for Safeguarding Classified Information. All others will return the report to: Commanding Officer, Fort Detrick, ATTN: Technical Releases Branch, Technical Infor mation Division, Fort Derrick, Frederick, Maryland, 21701. The findings in this piblieation are not to be construed as an official Department of the Army position, unless so designated by other authorised documents. i i 0 .\ CD CO *4 DEPARTMENT OF THE ARMY Fort Detrick Frederick, Maryland 21701 m i s c e l l a n e o u s PUBLICATION 37 wiwj-a ovisION-- PLANT Si 5TAG2OEKT Vesta Z . Mattie November 1570 \ Office of Director PLANT SCIENCES LABORATORIES C 0 6 5 CO c .h CO CD '' ] T rn n r^ n p ^ ^ ' : r=nr=r Cri; I m O O'0 E ***# *. CO JbJCa i f a j* i J i (0) ABSTRACT ; i t i (0) The activities and accomplishments of personnel \ in Crops Division-Plant Sciences Laboratories, headed by \ JDivision Chief and Director, Dr. Charles E. Hinarik, are } narrated from the time Crops Division was established in October 1943 through 1969. The history narrates the / l development of chemicals for military use in vegetation and crop control and the development of systems for crop destruction by pathogens. Research of personnel published in open literature and as government reports is documented in detail throughout the report. The Author Index includes more than 400 literature citations and references. co CD rr 'J.. CHOPS DIVISIOH Oct 19t)Stp 19t5 Chief, Dr. A. G. Hrnen (Civilian) (Military Organization) Sep 1943 ; S*p 1946 Scp 1946 Jul 1932 Chief, Dr. C. E. Mlnarlk (Civilian Organization) Chief, Dt. A. C. Herman Deputy Chief, Dr. . E. Mlnarlk Jul 1932Jul 1933 Chief, Dr. C. E. Mlnarlk Jul 1935* 31 Dec 1959 Chief, Dr. C. E. Mlnarlk 1 Jas 19589ep .1959 Sep 1939JO Sep 1967 Chief, Dr. C. E. Hlnarlk Chief, Dr. C. fc. Mlnarlk Biological Chemical Biological Branch Chemical Branch Biological Branch Chemical Itranch LT. Axel L. nderten CAPT. William Eppa CAPT. U. W. Dorre11 LT. R. M. Paga Chief, Pilot riant Branch Dr. A. C. Norman Chlef, Dr. Berch W. Henry Chlef, Dr. C. E. Htnnrik `Chlef, Dr. Berch W. Henry Chlef, Dr. lan W. Tervet [Chlef, Dr. John E. Hlfcchell Chlef, Dr. C. E. Htnarlk 1946-Sep 1947 Oct 1947-Jul 1931 Jul 1931-Jul 1932 Dialogical Branch Chemical Branch Chlei, Dr. J. E. Mitchell Dr. R. L. lieIntraub Biological Branch -- Blo. 1 Chlef, Dr. John E. Httchll Chlef, Dr. Chrli C. Schmitt Jul 1933-Aug 1936 Aug 1956-Dcc 1937 Blo. 11 Chlef, Dr. C. H. KIngtolver Chemical Hrneh Phyelology Branch Cheralatry Branch Operational Requlr*- menta Branch,1 >. Chl.it, A. L. Welntraub ChUf, Dr. A. S. Newman Chief, Hr. H. M. r.ker Crop RAD program dtccontlmied. Small atoff retained for poaalbla reactivation. Inlologlcnl Branch Chemical Branch Chief, Dr. C. H. Klngaotver Chief, Dr. R. A. Darrow 19621962- zs-ocseo  m% n1rr.' '<** v* r?*** I ",- J t ,, I X PLANT SCIENCES LABORATORIES l Oct 1967- 3i Hay 1968 I June 1968 to frtent date. OFFICE OF DIRECTOR Dr. C. E. Hlnerik Adnlnlstratlve Servlcee Office Hr*. Carolyn K. WrilVor_____ Fiant Pathology DlVtaion Chief, Dr. C. H. Kingaolver IResearch Branch I Resecrch Branch II Eplphytology Branch Fiant Physiology Division Chief, Dr. R. A. narrow Field Project* & Support Dlvlaton Chief, Hr. L, U. Boyer IRaatarch Branch Chemical Evaluation Branch Mon* OFFICE OF DIRECTOR Dr. C. E* Hlnerik Attainlatrettve Services Office Hca. Carolyn H. Walker_____ Fiant Pathology Division Chief, Dr. C. H. Klnpaolver Plant rhyxloloiy Division Chief, Dr. R. A. Darrow Field Projects A Support Division Chief, Hr. L. V. Boyer ___ Chief, Dr. K. R Brcrafield Chief, Dr. F. H Lat.terell Chief, Hr. T. L Horgan Chief, Dr. F. B| Abelea Chief, Dr. C. B Truchelut I I I I I i (U) Organization, Cropa Division-- Plant Sciences Laboratories, 1943 to Freaeat, (U) G80GSG0 . . . . ! n ' - .ntusfRrwt' in I 6 (U ) Pr. Charles . UlnariJe, Chief, Crops division-- Director, Fiant Sciences Laboratories, 1952 to Present. (U) CO en CO O I (U) FOREWORD (U) Dr. Charles . Minarik, an Internationally recognized authority on * plant physiology and chemistry, organized Crops Division as a civilian organization in 1946, and since 1952 he has directed Its activities (now Plant Sciences'Laboratories). In 1959 he reestablished the anticrop and defoliation research and development programs of the Department of Defense that were phased out in 1957 because of limited funds and a lack of clear indication of military utility. Through his foresight and the dedicated efforts of his research group that-he led and is leading, the United States military forces in Southeast Asia are equipped with defoliation and anti- y crop weapons that are materially assisting them in combating the enemy. ^ Dr. Minarik has visited Vietnam and ether parts of Southeast Asia numerous times as a consultant to the U5AF, the Advance Research Projects Agency (ARPA), the Military Assistance Command Vietnam (MACV), and the U.S. Embassy on matters relating to defoliation and antiplant activities. Some of his ' more important accomplishments from 1954 through 1969 include: (1) serving as editor of Herds (now Weed Scihce), a quarterly journal issued by Heed' Society of America (now Heed Science Society of America) in 1954 and 1955; (ii) becoming in 1962 a member of the original 203 Committee that coordinates defoliation and anticrop operations in Vietnam, and recognition by the 202 Committee of the Vietnamese Joint General Staff for his contributions to the defense of the Republic of Vietnam; (ill) serving on a consulttee of the National Academy of Sciences, National Research Council, from 1961 through 1966; (iv). serving as consultant to the U.S. Ambassador to Bolivia, who requested his on-site consultation on vegetation control Barters In that country in December 19C5; (v) becoming an honorary member of .the Staff and Faculty, U.S. Army Chemical Center and School, Fort McClellan, Alabama, on 25 May 1966 and serving as a gu*.st lecturer on defoliation; (vi) investi gating alleged damage to rubber in Vietnam, in 1967 by invitation of the U.S. Embassy, Saigon; (vii) assisting Headquarters MACV from 17 March through S April 1968 in conducting tl.p Herbicide Policy Review; (viii) serving as a member of the Su b c o m i t t ee on Defoliants/Anticrop Systems of the Joint Technical Coordinating Group for Chenical/Bioiogical (JTCG/CS) since 1967; (ix), serving as Chairman of the Standing Subpanel E-2.5 on Plant Sciences, The Technical.Coordination Program (TTC?) since 1968; (x) evaluating the alleged damage to rubber and other crops in Cambodia in June and July 1969 as a member of a team of scientists at the request of the State Department; and (xl) presenting invitational papers throughout the years before various professional societies. (U) Dr. Minarik1s activities in research and development have included visits in 2 2 foreign countries, and because of his distinguished service to the National Defense* of th United States, Major General Frank G. White, Commanding General, U.S. Army Munitions Command, awarded him the Major General Amos A. Fries Gold Medal of the American Ordnance Association on 2 November 1967. S. -3 'rit- ,i . I 4 i i f j , | 9 (0) CONTENTS A b s t r a c t ................. F o r e w o r d ..................... 3 7 I. BACKGROUND, 1943-1965 . 13 A. Activation ........................................... .. 13 B. Early Research with Four Plant Pathogens . . . . . . . . . . . 1 3 C. Crops Division., Military to C i v i l i a n ......................... 15 D. Pioneer Development of 2,4-D and 2,4,5 - T ......................15 1. Early History .............................................. 15 .2. Contributors Toward Early Development ........... . 19 E. First Aerial Sprays with Diluted Chemicals . . . . . . , . . . . 21 1. *B-25 Aircraft-- Fort Knox, K e n t u c k y ....................... 21 2. B-25 Aircraft with Standard M-10 Smoke Tanks-- Florida Everglades . ; 21 3. B-26 Aircraft with Standard and Modified M-10 Smoke Tanks-- Bushn-ill A m y Air Field, Bushnell, Florida . . . . 21 4. A-20-G (Now S-26 Aircraft) Attack Bomber with Modified M-10 Smoke Tank-- Vigo Plant, Terre Haute, Indiana . . . . 22 F. Aerial Sprays with Undiluted C h e m i c a l ....................... 23 1. C-47 Airera fr.-- Avon Park, F l o r i d a ........ .............. 23 2. Navy XBT 2D-1 with Navy Aero X 2A-- Avon Park, Florida . . 24 3. USAF B-17, USAF B-26, TISN AD Skyraider, USN F4TJ Corsair-- Avon Park, F l o r i d a ..................... .................. 24 4. Modifications Resulting in Development of Hourglass-MC-1-- Eglln Air Force Base, Florida ............... 25 5. Navy F3D Jet Fighter with Aero 14A Airborne Spray Tank . . 25 6 . U.S. Navy F3D-1 Jet Aircraft with Navy Aero 14A Airborne Spray Tanks-- Avon Park, Florida .......................... 25 G. Greenhouse and Field Investigations with Chemicals at Fort Detrick and Elsewhere ........ . . . . . . . ............... 26 H. Initiation and Development of the Defoliation Program . . . . 27 1. In-House Screening of Chemicals in Earlier Years ........ 27 2. Greenhouse Screening and Field Testing Programs . . . . . 28 I. Early History of the Activities of the Biological Branch . . 2S J. Pioneer Research on G l b b e r e l l l n ..............................29 K. Stem Rust ............. .................... .................. 30 1. Development of Equipment for Cereal Rust S y s t e m ............30 2. Cereal Rust Production at Various Sites ........... 31 3. Development of Laboratory Assessment T e c h n i q u e s ...........31 L. Preliminary Studies on Leaf Rust .............................. 32 M. Early Work on Plant Viruses . . ............. ' ............... 33 N. Development of a System for R i c e ..................... . 33 1. Field Studies ...................................... .. 33 .2. Etiology of Ptice B l a s t ....................... 34 O. Development of Mobile Units for Rust Spore Analyzing, Processing, and Packaging . . . . . . . . . . . ............. 35 CO cn CO CO CO I 10 I F. Inhibitor S t u d i e s .......................................... . 36 ; Q . P h a s e - O u t .................................................... 36 R. Analogue Area Studies ........................................ 37 n . CROPS DIVISION, FY 1965-1967 ................................... , 39 A. Chemical B r a n c h ...................................... . . . . 39 1 1. Mission ............. ..................................... 39 ! 2. Professional Stature of P e r s o n n e l .................... 40 U 3. Synthesis and Screening Programs-........................ 41 i 4. Defoliation Tests in Thailand . . . . ................... 41 5. Crop Responses to Herbicides ................... .. 42 6 . Chemical Data Processing and Information Retrieval . . . 43 i 7. Basic Research in Abscission . . . . . . . . . . . . . . . 44 ; 8 . Basic Research vlth Herbicides and Adjuvants ........... 45 B. Biological B r a n c h ............................. 48 1. Hission 48 2. Professional Stature of Personnel .`............ . . . ' . 49 i 3. Rice Blast . . ............ .50. > 4. Stem Rust of W h e a t ............... 55 5. Cryogenic Storage ........................- .............. 56 6 . Stripe Rust of W h e a t ........... 57 ; 7. New A g e n t s ............................................. . 59 8 . P h a n e r o g a m s ............. ................................. 63 9. Ergot Alkaloid R e s e a r c h ............ .... ................ 63 III., PLANT SCIENCES LABORATORIES. FY 1968 ................. .. 65 A. H i s s i o n .............................................. .. . . . 65 . 1. Office of D i r e c t o r ....................... ........... .. 65- 2. Administrative Services Office ......................... 65 B. Activities and Accomplishments of Deputy to Director . . . . 66 C. Plant Physiology Division (Formerly Chemical Branch) . . . . 06 1. Mission and Activities of Division andBranches . . . . . 6 S 2. Chemical Evaluation B r a n c h .............. ............. 6 ? 3. Research Branch .................................... .. . 73 D. Plant Pathology Division (Formerly Biological Branch) . . . . 76 1. Hission and Activities of Division and B r a n c h e s ......... 76 i 2. Research Branch I ......................... . . . . . . . 77 3. Research Branch X I ....................... ... 80 4. Epiphytology Branch . . . .............................. 82 ; E. Field Projects and Support D i v i s i o n ............. .. 85 [ IV. PLANT SCIENCES LABORATORIES, FT 1969 ........................... 87 * A. Plant Physiology Division ......................... ......... 87 1. Accession and Screening of Candidate Chemicals ......... 87 * 2. Field Testing of Defoliants and Soil-Applied Herbicides . 92 . 3. Field Tests of Chemicals on Crops .................... 92 4. Biological Effectiveness of Stull Bifluid Chemicals . . . 92^ 5. Herbicide Manual Prepared for U.S. AirForce . . . . . . 93 * 6 . Basic Research on Herbicides and D e f o l i a n t s ........ 93 ' 7. Basic Research on Abscission . . . . * ............. 94 i1 11 1I J B. Plant Pathology Division ........ 94 1 Nev Agents .. ............................................... 95 2. .Cryogenic Storage andPhysiology of Stem Bust . . . . . . 99 3. Phanerogams ................. 100 4. Rice Blast . . -.. , ........................... 100* 5. Epidemiology . . . . . . . . . . .......................... 100 C. Field Projects and Support D i v i s i o n ........................... 102 Literature C i t e d ........................ 105 References ............................. . . . . . . . . . . . . . 135 f. Author Index ............................... 145 Distribution List 153 DD Form 1473 ................................. 155 ( V ) FIGURES * Organization, Crops Division-- Plant Sciences Laboratories, i 1943 to Present ............................................. 5 t ; Dr. Charles E. Minarik, Chief, Crops Division-- Director, Plant * Sciences Laboratories, 1952 to P r e s e n t ........................... 6 ; 1. Wartime Staff of Crops Division . ............. .............. .. . 17 2. Plant Sciences Laboratories Staff,February 1970 . . '.................88 3. Staff, Plant Physiology Division .................................. 90 4. Staff,, Plant Pathology Division ..................................... 96 5. Staff, Field Projects and.Support Division ......................... -103 13 I. BACKGROUND, 1943-1965 A. (U) ACTIVATION (U) In 1942 Che War Research Service was established in Che Federal Security Agency and assigned the task of initialing research and development on biological warfare in the United States. As a/Tern It*-- Caap^petrick was activated by The Chemical Warfare Service (CWS) c n l O A p r i l 19j (U) Crops Division was established in October 1943 to conduct research and development on chemical and biological^ anricrop agent systems. Dr. A. Geoffry Norman., presently vice-president for research at the University of Michigan, was taken from another assignment at Camp Detrick and appointed the first Chief of Crops Division. B. $ EARLY RESEARCH WITH FOUR PLANT PATHOGENS & Several conferences were held among biologists of the National Reseicrcclh Council, War Research Service, and the United States Department of Agriculture, and as a result of these meetings, four plant pathogens, Sclerotiuc rolfsli, Phvtoohthora infestans, Helminthosp'orium oryzae. and Piricularia oryzae. were considered as possible biological anticrop agents. (U) Sclerotiun rolfsii was approved for investigation at Camp Dctrick in September 1943, but the first experiment was not Initiated until 22 October 1943 when Captain William M. Epps,* Plant Pathologist-- Plant Breeder, undertook the investigation. 1 He initiated another experiment on 16 . December 1943 using P. Infestans. 3 Work was being carried out on both of these pathogens before Crops Division was established. Scleratiua rolfsil was being investigated in early 1943 by Dr. Freeman Weiss, Dr. E.B. Lambert, and Dr. Dorothy B. Vaughn at Beltsville, Maryland, under a War Research Service project. At the same time another War Research Service project with P. infestans was being carried out by Dr. Bonde and Dr. Stanley Snieszko at the Maine Agricultural Experiment Station and by Dr. Weiss at the New Jersey Agricultural Experiment Station. Later Dr. Weiss used P. lnfestans in an experiment at Beltsville, Maryland. (UJ In November 1943, Lt. Axel L. Andersen,** assigned to Crops Division at Camp Detrick, was sent to Beaumont, Texas, to begin preliminary work on H. oryzae and P. oryzae with Dr. Edgar Tullis of the USDA. * Presently Professor and Head, Department of Botany & Bacteriology, Cleoson University, Clemson, South Carolina 29631. Home address: 211 Wyatt Avenue, Clemson, South Carolina 29631. ** Presently Department'of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan *48823. -- ^ --^ CO 14 (U) The first experiments with H. orvaae3 and P. oryzac1 were started at Camp Detrick on 23 February 1944 by Lt. Robert Meredith rage. Page, Assistant Professor, then Professor of Biology, Department of Biological Sciences, had been affiliated with Stanford University for 20 years (1948 to 1968) until his death 17 May 1968.* Because Lt. Andersen had worked on these pathogens prior to this date, he returned to Camp Detrick and began full-scale work. (U) Preliminary work on all four pathogens during late 1943 and most of 1944 consisted mainly of laboratory tests to determine environmental conditions necessary for growth, data collection on adaptability to largescale production, selection of media and substrates, and literature reviews. All work was preliminary because the planning committee had failed to provide for research in plant sciences, and sufficient personnel, facilities, and equipment were lacking. Therefore, early in 1944 the laboratory facilities in Building 201 of Fort Detrick were made available to Crops Division or work on plant pathogens. (U) At this time, the facilities of Crops Division consisted of a 5* acre test field located near the present parking lot near Building 330 and a small 12- by 25-foot laboratory in Building 201 that had been designated as a wash room when the building was remodeled. Later it was expanded to include half of another larger laboratory in which personnel of another Division were working on human pathogens. Because all research and services at Camp Detrick were carried on In Building 201,"personnel of Crops Division were required to conform to all safety regulations, making research on plant pathogens difficult. Under these circumstances, Captain Epps conducted the first greenhouse test with . rolfsli on 5 Hay 1944; then on 30 June he conducted the first field test with this pathogen. (U) When the laboratory in Eui^ding 201 was made available to Crops Division, three officers and two enlisted men constituted the Biological Section, an increase of one officer and one enlisted man. since the latter part of 1943. From February 1944, the strength of the Division had increased to the point that shift work was initiated so that the meager facilities could be used more advantageously.' One group of researchers worked from 0800 to 1600 hours and another used the same facilities from 1600 to 2400 hours. This setup continued until August 1944 when Crops Division moved into Buildings 321 and 325, the latter becoming Crops Division*s.Pilot Plant. (U) With the occupancy of both buildings and additional personnel, intensive laboratory, greenhouse, field, and pilot-plant experiments were * Raper, John R . ; Briggs, Winslow R. November 1968. RoberL Meredith Tage 19i>-1968. In Plant Science Bulletin 14:3:6-7. OJ on C.O d? 15 conducted on all four pathogens. Branch Chief Captain William Dorrell* and Dr. Edwin F. Lowe** worked closely with laboratory personnel in adapting these pathogens to pilot-plant production. Under their super vision, Captain Epps set up the first experiment in the pilot plant for the growth of S t rolfsii on 23 December 1944.5 Sufficient quantities of alI-foairpathogens"ft'te-- pfoucfed for~additional laboratory and field testing. (U) On 9 June 1945, In cooperation with Captain Tat lock of PC Division, experiments on the use of plant viruses as simulants for human viruses' were performed in the testing of gas mask canisters and protective clothing. C. (D) CROPS DIVISION, H H H A S y TO CIVILIAN (U) By late- 1945, Crops Division consisted of 26 officers and 16 enlisted men under a civilian chief, Dr. A.G. Norman (Fig. 1). Dr. Charles E.'Minarik, Plant Physiologist,***-Joined Crops Division in Hay 1945 and )r vas among the 26 officers assigned to the Division. Ee and 11 otherofficers and 10 enlisted men constituted the Chemical Branch, and*T4 officers and 6 enlisted men including T/3 Sgt. Thomas. L.. Morgan (February 1944) constituted the Biological Branch. To date, Dr. Minarik and Mr.' I Morgan'are the only wartime members left in Plant Sciences Laboratories.] (U) Dr. Norman resigned in September 1945, and Dr. Minarik became Chief, Crops Division. At the end of World War II and'during the early part of 1946, Dr. 1'li.iarik organized Crops Division as civilian organization. At that time 11 professionals composed the Division Staff. During early 1946 and until the end of 1947, the number of personnel increased gradually. Dr. Norman returned in September 1946, again to assume his role as Chief, Crops Division, with Dr. Minarik as his Deputy. Dr. Minarik vas also Chief of the Chemical Branch. In December 1947 the Division strength numbered 32 people, including seme military personnel either serving as technicians or working in the administrative branch. D. (U) PIONEER DEVELOPMENT OF 2,4-D AND 2,4,5-T 1. (U> Early History (TJ) Research in Crops Division has resulted in a number of develop ments that have been significant to the military -and/or the United States * Presently Technical Coordinator (), Directorate of Chemical and Nuclear Operations, Office of Assistant Chief of.Staff for Force Development, Department of the Army, Washington, D.C. ** Presently Special Studies Branch, Special Operations Division, Fort Detrick. *** Presently Director of Plant Sciences Laboratories, Fort Detrick. ^ ^ n co d? .\ Back Row Standing 1. Lt. F.W, Leaver (Dr.) 2. T/4 Landry 3. PhM2/c Jack Hyatt (Navy) , 4. Capt. H. Robert DeRosc (Dr.) (Deceased) 5. Lt. John C. Carpenter (Dr.) 6 . Capt. Stanley F. Snieszko (Dr.) 7. Lt. Arden F. Sherf (Dr.) (Navy) 8 . ` FhMl/c Fred Owlngs (Navy) 9. Ensign R.W. Allard (Dr.) (Navy) Front Row Standing 1. Capt. Daniel Ready ` 2. PhMl/c John G. Jakob 3. Lt. Axel Andersen (Dr.) 4. Y3/c Wolfe (Waves) (Secretary) 5. Lt. Berch W. Henry (Du.) (Navy) 6 . FhH3/c Givens (Navy) 7. Sgt. Houston G. Adams S. PhM3/c Ivy Freemen (Navy) First Row Seated 1. Capt. Robert Weaver (Dr.) 2 Lt. Carl, F. Swanson (Dr.) 3. Capt. David L. Taylor (Dr.) (Deceased) 4. Major John R. Taylor (Dr.) 5. Dr. A. Geoffry Norman, Chief l G0 ES 0 i 10. T/5 Edward Smith 11. U . Arthur Newman (Dr.) 12. Lt. Howard E. Thompson (Dr.) (Navy) 13. PhM2/c Bennett M. Goodloe (Navy) 14. Lt. John Patterson 15. Lt. Roy ,M. Acker 16. T/3 Thomas L. {'organ 17. Capt. Edward Cherry (Deceased) 18. Lt. Edwin P. Loue 9. Lt. Robert Hb Page (Dr.) (Deceased) 10. S g t . `Virgil E. Farmer 11. T/5 Robert G. Smith 12. T/4 Walter Pregler 13. Capt. Charles E. Hlnarik (Dr.) 14. PhM3/c Edwards (Navy) 15. Capt. William W. Dorrell (Dr.) 6 . Major William Eppa (Dr.) 7. Lt. William Ennis (Dr.) (Navy) 8 . T/4 Rebecca Boorsteln (WAC) (Secretary) 9. Capt. R. Marek 10. Ensign Margaret Mills (Navy) I V : CB0 ESEO __. . . . . .. 18 economy. The earliest, and possibly the most outstanding, contribution was I f the pioneering work on synthetic plant hormones as herbicides that led to the selection and development of 2,4-dichlorophenoxyacetic acid (2,4-D) an,* 2,4,5-trichloropheuoxyacetic acid (2,4,5-T). Early data on these com* pounds were developed during World War XI and were publicized in the open literature after the war had ended._^13_ * ,1*~2S The high potency ^.physiological^nu'TaorpKbIqgidalI3f 2,4-D and 2,4,5-T was first discovered by Zimmerman and Hitchcock iiCl942tSa Dr. E.J.^Kraus, who worked con currently at the University of Chicago as Head of the Botany Department and at the U.S. Plant Industry Station, Beltsville, Maryland, obtained samples from Dr, Zimmerman, and In January 1943 performed successful pre liminary experiments at the University of Chicago, then investigated the growth regulators more extensively at the Plant Industry Station. 2 7 After Crops Division was established in 1943, it sponsored this research. 1 (U) Early in 1944, Captain H. Robert DeRose and Captain David L. Taylor were detailed from Crops Division to the Plant Industry Station at Beltsville to carry out field experiments with 2,4-D and 2,4,5-T. b e c a u s e the U.S. Army was considering the feasibility of using these .growth regu lators for the destruction of enemy crops, the work conducted by these men at the Station, and thetr subsequent research on growth regulators at Camp Deerlck was not published/^" i (U) Dr. Kraus continued to have access to the work at Camp Detrick. He was also editor of the Botanical Gazette. - Dr. Kraus was concerned when he received a paper for publication on these growth regulators in 1944 from Drs. Charles L. Hasmer and H.B. Tukey (the latter Head of the Horti culture Department at Michigan State). He also was aware of a paper of Drs. John W. Mitchell and Banner on work done while Hamper was still at Beltsville, one that Dr. Mitchell was holding for later publication. Dr. Hamner had already left the Plant Industry Station, and after assisting Kraus and Mitchell with their, experiment with 2,4-D and 2,4,5-T, he under stood the objectives. 20 Dr. Kraus released this paper2 9 because he could think of'no valid reason to withhold publication without breaking security. Therefore, he released the paper by Mitchell and Hasmer.3 0 (U) In September 1944, Dr. James W. Brown transferred at the Bureau of Plant Industry to work with Dr. Mitchell and conduct the testing of chemicals for growth-regulating activity In conjunction with the work at Camp Decrick. 3 1 * 3 2 In February 1947, Dr. Brown transferred to Camp Detrick to further the research in this area. 3 3 *1" * 3 (U) During the period February 1944 through 1945, Camp Detrick personnel intensively synthesized and screened a broad array of synthetic plant hormones. Lt.(jg) Howard E. Thompson, USSR, a keen and resourceful chemist, with a dedicated assistant, PhMl/c Fred J. Cwings, USNR, synthe sized more than 1,000 chemicals during this period. Lt.(jg) Thompson devoted most of the day and night to his research, his time out for sleeping consisting mostly of naps on laboratory benches or foot lockers. A 19 synthesis contract with Ohio State University supplemented the Camp Betrick synthesis effort* New growth regulators were tested and evaluated in Crops Division and the USDA (cross-service agreement). (U) As a result o the synthesis and screening o.f many chemicals; the phenoxys, 2,4-D and 2,4,5-T, were identified as outstanding herbicides), and a mass of basic and applied data9 - 2 5 ' 3 3 " e 9 on t'ieir activities was developed under the guidance of Dr. Norman and Dr. Ilinarik until 1952; when Dr. Norman resigned; then under Dr. Minarik throughout the history of Crops Division. (U) In the postwar period, the Camp Pet rick group that was studying plant-growth-regulator-type herbicides w as the foremost group in the world engaged in this type of activity. Release of information to the public " -fifttil World war b'-J caused revolutionary changes in weed control practices throughout the world and resulted in the development of many nev industries and a new body of scientific .literature. It has been estimated that during 1960 (prior to military' use in Vietnam) the United States pro duced 50 million pounds of these chemicals annually for agricultural use. Since 1961; military requirements have caused expansion of the United States production capability. 1. 2. (U) Contributors Toward Early Development (U) The principal investigators at Camp Detrick who contributed to the early developments of defoliants and chemical anticrop agents were: Dr. A.G. Norman (presently Vice-President for Research; University of Michigan, Ann Arbor, Michigan). Directed the program and maintained liaison with the using agencies and higher headquarters.5 ,7 ,8 *4B- 4 7 so,e s ,6 8 ,7 5 - 7 4 . ey.se Dr.'C.E. Minarik (presently Director of Plant Sciences Laboratories, Fort Detrick, Frederick, Maryland). Worked on spray applications, effects of rainfall subsequent to spray applications, and root absorption by plants grown in nutrient culture.13" 13* *-5 0 *Sl~6 " 66.,s:%,7 0 ,7 5 - 7 5 Dr. A,S, Newman (presently with Cooperative Research Service, U.S. Depart ment of Agriculture, Washington, D.C. 20250). lLt. Neuman joined Crops Division staff (Dr. Norman's first graduate student) as an Army Air Corps aerial photographer. From 18 February 1946 through 4 October 1957, Newman, civilian research agronomist, studied the effects of soil microflora on the persistence end decomposition of 2,4-D and other herbicides when applied to variev" types of Dr. W.B. Ennis, Jr. (presently Chief, Crops Protection Research Branch, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland). Developed the first invert emulsions, devised spray techniques, and studied droplet sisa.3 i5 * 1 ,a i * s , 6 2 , E 7 7 e , e i CO c-o (ji co CO CO on 20 Dr. H.R. DeRose (Deceased 2 February 1969). Screened plant growth regulators for activity on various agricultural crops and studied the persistence' of herbicides in soils until his retirement from Crops Division 31 August 196S.1019" 2 1 *7*78 '01,03 Dr. H., Thompson (presently Dugway Proving Ground, Utah). Headed a synthesis group that synthesized more than 1 , 0 0 0 compounds. 0 1 0 , 7 8 Dr, C.P, Swanson (presently Associate Dean for Undergraduate Studies, Johns Hopkins University, Baltimore, Maryland'21218) .**9*11,1S" 1 9 , 7 0 Dr. R.J. Weaver (presently Department of Viticulture, University of California, Davis, California 95616).10,12,13,17,21 - Dr. F.T. Boyd (presently, Agronomist, Florida Experiment Station) . 1 3 , 1 5 , 1 7 , 1 0 Dr. H.H. Smith (presently Geneticist, Department of Biology, Brookhaven National Laboratories, Upton, New Turk 11973).6,14 Dr. R.W. Allard (presently University of California, Davis, Calif.),10,10,21. Dr. D.L. Tavlor (Deceased) .32" 2S Mr. Daniel C. Ready (Retired-- Ridge Road, Braddock Heights, Maryland) . 4 4 , 5 9 Mr.. Roy M, Acker (presently Manager, Market Planning, Allison Division, General Motors Corporation, Indianapolis, Indiana 46206). Laid .the ground work for the defoliation systems currently in use In Vietnam.1* Dr. R.L. Welntraub (presently Professor of Botany, Department of Biology, George Washington University, Washington, D.C.; also Plant Physiologist, Radiation Biology Laboratory, Smithsonian Institution, Rockville,- Maryland). Conduted extensive research on the mechanism of action of plant-growthregulating c h e m i c a l s * 2 4 3 **a,sc,5 4 , & 5 se. as-s7 fe7-- os (U) The USDA scientists who worked on Army contracts were: Dr. J.W. Mitchell (presently Plant Physiologist, Bureau of Plant Industry, U.S. Department of Agriculture, Beltsville, Maryland). Dr. J.W. Brown (Plant Physiologist, also Deputy to Dr. C.E. Minarik, Office of the Director, Plant Sciences Laboratories, Fort Detrick, Frederick, Maryland, until his retirement 28 February 1969. Transferred to Camp De Crick February 1947). * Events discussed in text. CO cn CO CD CT3 E. (U) FIRST AERIAL SPRAYS WITH DILUTED CHEMICALS (U) The crash program of synthesizing and screening chemicals was the result of a request from the U.S. Army to Investigate chemicals that were available in large quantities in. the United States that would defoliate tree's^- `shrubs~gr orft tovarsj^and vines." At chat time, there was a great deal of Interest in destroying vegetation in the South Pacific Theater, and the principal means available was high explosives. Millions of tons of high explosives were required to destroy vegetation on these Pacific Islands. 90 1. (U) 3-25 Aircraft-- Fort Knox, Kentucky 1 (U) The screening, program yielded two chemicals of' promise, ammonium thiocyanate and zinc chloride. In cooperation with the Armored Medical Research Laboratory, personnel sprayed temperate zone vegetation at Fort Knox with these two chemicals and with other chemicals with excellent results. The spray treatment was followed with incendiaries that were dropped from B-25 aircraft. 90 L 2. (U) B-25 Aircraft with Standard M-10 Smoke Tanks-- Florida Everglades (U) In another program that dealt with subtropical vegetation in the Florida Everglades, Captains Weaver and Taylor and Lts. Page, Carpenter, and Newman under Dr. Norman's leadership conducted successful aerial sprays in March and April 1944 and In August and September 1944 at two locations in Florida, at Marathon and at Orlando (the latter site 90 miles west of Orlando-- a forested area that included part of the Chassahovltzka Swamp). Aqueous solutions of ammonium thiocyanate and zinc chloride were sprayed ' from B-25 aircraft with standard M-10 airplane smoke tanks with excellent results. The vegetation changed color in 2 or 3 days and defoliation occurred in 4 or 5 days, resulting in effective target marking. 9 1 (U) Because the United States might be accused of conducting poison gas warfare (the word thiocyanate sounded very much like cyanide), these chemicals were not used in the Pacific Theater. The war ended before another defoliant could be developed. 90 3. (U) B-26 Aircraft with Standard and Modified M-10 Smoke Tanks-- Bushnell Army Air Field, Bushnell, Florida (U) After working with the phenoxvs and other growth regulators in the greenhouse and field at Camp Detrick, personne 1 from Camp Detrick tested some of the agents at Bushnell Army Air Field, Bushnell, Florida, i/ with the cooperation of personnel from Dugyay Proving Ground Mobile CWS Unit aaj AAFTAC personnel at Orlando Annv Air Base. From February through April^ 1 9 4 5 X t s . R.M. Acker, J.B. Carpenter, A.S. Newman, and Harold H. Smith (USiiR), with Major H..Hall. Capt. D.L. Taylor, ar.d T/4 C.G. Wyckoff tested the practicability of destroying crops with diluted ^2f4^D and its CO cn axnoonium salt sprayed from standard M-10 chemical smoke tanks mounted on 1 v> % / g '- t f \ (I 22 tactical aircraft, A-26 B airplanes (attack bombers). Preliminary tests also were carried out with a modified M - 1 0 tank with reduced orifice plate and venturi tailpipe, and with the E-2 bomb bay chemical spray tank installed in a TB-25J airplane. Both agents sprayed from standard M-10 chemical smoke tanks caused severe injury or destruction of crops (potted plants were used as indicators). Less than 1 pound per acre of 2, 4-D in oil destroyed crops (other than cereals) , 00 (U) Natural vegetation primarily affected by spray drift (2,4-D in oil and its anmonium salt in water) incidental to other trials showed charac teristic symptoms of injury in the younger growth. 69 4. (U) A-20-G (Now B-26 Aircraft) Attack Bomber with Modified K-10 Smoke Tank-- Vigo Plant, Terre Haute, Indiana (U) Further extensive research in destroying crops by aerial.spray operations was carried out at Vigo Plant. CWS, .Terre Haute, Indiana, and at RpmMBnnr) T p v b c (limited operations on connaeria.lly planned irrigated rice at the latter). From April through 0ctober(j 9 4 ^ nine officers and one' nilsted man (T/4 C.G. Wyckoff, CVS) from Crops Division, aided by some enlisted personnel for field work and ground operations from the Technical Department, Vigo Plant, conducted 104 missions in the area. There were 81 missions over grid areas (where potted plants and indicator cards were set up) or over weed fields and 23 missions over a variety of field crops (planted in strips) in different stages of development. 7 0 (U) At the Vigo Plant, Cant, C.E. Mlnatik, Cav; 1st Lt. R,,M. Acker, CWS; Lt. W.B. Ennis, USNR; M a j o r `H. Hall, AC; 1st L t. A.S. Newman, AC; Lt. H.H. Smith, USNR; Lt. C. Swanson, USNR; Capt. D.L. Taylor, CVS; and Uapt. H.W,' Wheeler, CWS, intensively investigated and modified equipment, solutions, agents, and related droplet distributions to plant responses. They confirmed and extended the results of tests carried 'out at Busline11 Army Air Field and further demonstrated that by installing a reduced orifice adapter (recommended 3^-inch opening) on the M-10 airplane smoke tank mounted on a A-20-G (now B-26 aircraft) attack bomber, the swath length would be increased 25Z, with no apparent reduction in effective width. They ...tested the suitability of an alternative large-volume spray tank (550gallon bomb-bay Installation for the B-25 airplane) for disseminating cropdestroying agents and reduced the lag period between beginning of discharge and attainment of full flow rate by adding an air collector scoop attached to the air inlet, placing the contents under small positive pressure. The preferred discharge rate was 3.5 to 4.0 gallons per second at an altitude of about 1 0 0 feet and a speed of 2 0 0 mph.7 0 (U) The officers thoroughly investigated solutions and agents. They tested such items as * 'nA 7 i/`itp T and their various esters and studied spray volumes in relation to agent concentration; compared agents; determine the most satisfactory oil-type carriers for agent dissemination; and als<: tested spray solutions after adding a coagent or a wetting agent.70 G60S&U .1 i I r i r if b-- t -.jiiliMiifSR .. .11 e V F*fI' 23 i t CU) Twelve missions were reserved for comparing agents (phenoxyacetic ; acid type) that were as good as, or better than, 2,4-D as Inhibitory or herbicidal agents. One was easier to manufacture. Four other agents were -directly-miscible.n-ciJ-and-thercfcrc required no ccsclvent such as tri- buuylphosphate. Dr. Minarik et al. made valid comparisons between spray density as revealed on the indicator cards at any one station and plant responses at the same station as judged by the degree of inhibition of new growth. 70 I I (U) Additional agents that shoved inhibitory action comparable to 2,4-D in static trials proved to be at least as effective in the field. The oil sprays.were more effective than water sprays at similar spray densities and agent concentration. The investigators recosmended that the production of ethyl ester of 2,4-D be considered for direct incorporation into oil for crop destruction. 7 0 (U) The following year (12 to 14 August 1946) Newman and Ennis , returned to the Vigo Plant to determine the enduring effects of such sprays upon annual and perennial vegetation. They found that Insufficient chemical was present in the soil to affect the growth of soybeans or c o m that was planted the nei:t>year. There was no noticeable reduction in the weedy plant population in areas treated the preceding year with aerial sprays of plant inhibitors, ranging in concentration-from 1 to 15Z.71 F AERIAL SPRAYS WITH UNDILUTED CHEMICAL . 1. (U) C-47 Aircraft-- Avon Park, Florida (U) After demonstrating the feasibility of releasing diluted agent, from aircraft at Vigo, Indiana, field tests were set up at Avrm T^ri^ Tin?jM * 1 to demonstrate the feasibility of releasing undiluted agent from aircrart. The tests at Avon Park were conducted by Mr. Roy M. Acker, project leader, who contributed significantly to the program. His work on aerial spray systems for military aircraft and his dissemination trials at Avon Park Air Force Base, Florida, and Edgewood Arsenal, Maryland, laid the ground vork for the defoliation systems currently in use in Vietnam. The agent used \ in Vietnam was one that he selected-- mixed butyl esters'of 2,4-D and \ 2,4,5-T.* (U) Acker conducted the first aircraft releases (crosswind and upwind) of undiluted agent from c C-47 aircraft (furnished by Commanding General, Tactical Air CossnajidjvLangley Air Force Base, Virginia) at Avon Park during the spring of ^ 9 5 i p He and Roger W. Hartmeyer** et al. -- V/ * Personal letter from Dr. Hinarik to Mr. Acker on 3 March 1969. ^ ** Presently Deputy in Directorate of Munitions and Equipment, -Air Force Systems Command, Andrews Air Force Base, Maryland 2C331. CO cn CO conducted tests to determine if low-volume highly concentrated anticrop agents .could be sprayed from aircraft both effectively and practically. They also conducted teats to determine (i) droplet distribution obtained from various atomizing devices, (ii) rates (gal/acre) of undiluted agent that severely inhibited or killed young potted plants (arranged on sample lines of a grid), and (iii) lethal swath widths in crosswind flights at di." .erent altitudes and flow rates. 79 2. (U) Navy XBT 2D-1 with Navy Aero X 2A-- Avon Park, Florida (U) During these trials Acker et al. also tested the performance of the Navy Aero X 2A spraying device that they mounted on a Navy XBT 2D-1. This equipment was developed by the Navy to meet a requirement for insecti cide sprayers that could be attached to and removed from combat aircraft. Therefore, they conducted flights to determine whether this general type of sprayer might be adjpted for low-volume antierpp spray operations. Upwind flights were made primarily to obtain particle size and distribution data, and crosswind flights for determining maximum effective swath widths.79 3. J USA? B-17, USAT B-26, USN AD Skyraider, USN F4U Corsair-- Avon Park, F K rriidda A ^ I n the fall of ^951> at Avon Park, Acker, Hartmeyer and others conducted low-volume anticrop aerial spray trials (49 missions) using tHe USAF B-17, USAF B-26, USN AD Skyraider, and a USK F4U Corsair to disseminate undiluted butyl 2,4-D (Agent 143), isopropyl 2,4-D (Agent 167), and butyl _gf4rV -T (Afrent 974). The Commanding Generals of Warner Robins Air Force liase, (reorgia, >and MacDill Air Force Base, Florida, provided essential logistical support. The commanding Officer, 3210th Chenrtial and Ordnance Test Group. Aberdeen Proving Ground, Maryland, from 110th Chemical Test Squadron, Army Chemical Center, Maryland, furnish. *. the fi-17 and B-26 --- aircraft and experienced test pilots and crews. The Malaria and Mosquito Control Unit No. 1, Jacksonville Naval Air Station, Florida, furnished the Navy AD Skyraider, the F4U Corsair, Navy dispersal equipment, and per^ sonnel vhj participated in the Navy phases of these trials. The dual spraying system that proved most valuable in the assessment trials was originally developed by the Forest Insects Laboratory of the Division of Forest Insects Investigation, USDA. The test director stressed the investigation of (i) behavior of agent when discharged from various atomizing devices, (ii) effects of airspeed on spray characteristics, (iii)'effects of location of atomizing devices on distribution of the spray, and (iv) effects of altitude of release on swath characteristics. The location of the atomizing device greatly affected the behavior of the droplet cloud, ^.major finding in these tests. The chemical anticrop agents proved potent, ^ ^ t became known beyond q u e s t i o n ^ that 0 . 1 to 0.25 lb. per acre would cause kilting of plants or severe yield reduction in many major economic ert ;; Recovery of sprays upon the ground was high for all three agents. From la: obtained, personnel determined that an adequate installation for chemical anticrop spraying probably would be relatively simple In design and suited for placemens in bomber-type aircraft without extensive modification. 80 U lS f i I :: / / ,** i l I A. (U) Modifications Resulting in Development of Hourglass-KC-1-- i Eglin Air Force Base, Florida -- I > 1 (U) The third seri&^of chemical aerial spray trials vas conducted in N< -ember and December-- after the Division Chief, Dr. A. G. Norman, resi^u.d and was replaced by Dr. C.E. Minarik who formerly wa$ Chiefs Chemical Branch. The trials were conducted jointly by Chemical Corps and Air Force i personnel at Eglin Air Force Base, Florida, with R.K. Acker as Project i Leader. The tests included an Air Force project*-- that of evaluating a f large-capacity spraying system for'installation in B-29, B-50, and C-119 vV aircraft. Optimal flow rate for maximum utilization of agent was determined i ( 1 0 0 gal/mih recommended for broadleaf crop attack), based on the finding of lethal swaths ranging from 8 , 0 0 0 to 20,500 feet as determined with pot: ed j. test plants. Data collected at flow rates of 50, 100, 150, and 200 gal/min < i permitted recosmendations for optimal flow -rates to be used in effectively I treating a given target area. The engineering data that Acker et al. . collected with this prototype large-capacity spray systerP3 subsequently led to the design of the "Hourglass-MC-l," the first system to be used in Vietnam. This system, standardized and built for the U.S. Air Force by Hayes Aircraft Corporation, ^ 2 has been adapted for use in the C-123 and has been the major spray system that has been used in Vietnam since 1962. In Dr. Minarik1 s letter to Acker on 3 March 1969 he states, "We made a few changes in flow rates and used wing booms, but ve regard it as a modified 'Hourglass' system* With the sound background information that you developed, it vas simple to make changes that would .dapt the Hourglass for use in the C-123, with a three-gallon per acre deposit." 5. (U) Navy F3D Jet Fighter with Aero 1AA Airborne Spray Tank (U) In the spring Acker, Hartseyer and others dispersed -standardized chemical anticrop agents, butyl 2,A-D, and butyl 2,A.5-T from the Navy F3D jet fighter at 100-, 300-, 500-, and 700-foot altitudes, with speeds of 360 knots, ising two Aero 14A Airborne Spray Tanks. The results were highly satisfactory. Sprays that were released at 700 feet effectively treated a swath 7,000 feet vide and more than 8 miles long, representing an area coverage of 10 square miles per sortie. Sprays released at 300 feet produced areas highly .overdosed, resulting in inefficient agent utilization.0* 6 , (TJ) U.S. Navy F3D-1 Jet Aircraft with Navy Aero 1AA Airborne Spray Tanks-- Avon Park, Florida 1 (U) Additional trials were included for the fall of 195A at Avon Park. Acker et al. conducted and completed the trials in January 1955, seeking further information on the dissemination of chemical anticrop agents. They used two Navy Aero 1AA Airborne Spray Tanks (manufactured by Edo Corporation) mounted on the wings of-a U.S. N a v y F3D-1 jet aircraft and .particularly studied the effect cf altitude of spray release on swath charaq^ teristics and the effects of airspeed on spray atomization. Higher altitude^ spraying resulted in greater swath widths. Sprays released in crosswind ^ missions at altitudes of 1,500 feet produced average effective swaths of -26 . 17,425 feet in contrast to an average of 7,190 feet obtained from previous tests in which sprays were released at 700 feet. From data obtained, it was calculated that a. single jet aircraft using Luo tanks could effectively treat about 2 0 square miles of susceptible broad-leaved crops per sortie in 51 seconds pver_the_ target undex-^. variety, of meteorological conditions. WKen they increased the airspeed from 180 to 360 knots, the mass median diameter of the droplets decreased from 273 to 170 microns. Because finer spray droplets were expected to produce a more uniform deposition with an increase in area coverage, higher airspeeds were suggested in future tests for possibly obtaining finer spray atomization. 'Further studies were recom mended for establishing an optimum spray release altitude for maximum coverage. 86 ..... .'7 G. (U) GREENHOUSE AND FIELD INVESTIGATIONS WITH CHEMICALS AT FORT DETRICK AND ELSEWHERE * (U) While the chemical aerial spray trials were* conducted in the field a n d `equipment was being perfected, the Chemical Branch at Camp Detrick was investigating other phases of research: Pre-emergence herbicides and their \ behavior;5 1 Influence of different carriers upon the inhibitory properties J of growth regulatory sprays;5 2 New growth-regulating compounds;93 Disappear- ance of 2,4-D and 2,4,5-T from soil; 5 3 Behavior of droplets impinging on \ leaves of different species; 94 Studies on the relation between molecular ; structure and physiological activity of plant growth-regulators: I. Abscission-inducing activity; 3 7 Metabolism of 2,4-D; 3 8 5 4 A root elonga tion test for herbicide screening; 40 2,4-D - Mechanisms of action; 55 Herbicides: Chemical weed control; 56 Halogenated phenyl alkyl ethers as plpnt growth-regulators; 95 Precision sprayer for small plots; 96 New growth- : regulating compounds: TV, Selected toloxyacetic acids;B&/^Species sensitivity to chemicals tested for herbicidal properties.?3^ (U) Defoliant and desiccant chemicals were being screened and inves tigated intensively. S 7 ~ 1 0 4 (U) During 1954 and 1955, SF3 J.R. Whiteley, SP3 E.B. Hinton, and SP3 B.C. Patten, Jr. conducted greenhouse and field defoliation investigations, including selection of active compounds, field testing, variation in response . among species, and comparison of the effectiveness of two of the tost premising compounds. 96 In field applications at Fort Detrick, plants were treated with a battery-operated portable sprayer. 90 This equipment permitted application of small volumes to small areas of foliage (approximately 2 ft2) . It also was used in a forested area at Port Ritchie (9 and 11 August 1955) to spray endothal on selected branches of various species* Previously (March and April 1955) chemicals had been applied to plants (in 16-ft2 areas) (1 nl/16 ft2 was equivalent to 0.75 gal/acre) at Avon Park with e 250-ml hand sprayer operated by carbon dioxide and equipped with a flat-spray Teejet nozzle. In all areas (Gasp Detrick, Maryland; Avon Park Air Force Base, Florida; and Fort kitchie, Maryland) disodium 3,6 -endoxohexahydrophthalate and 2-butyne-l,4-diol were the most effective defoliants on woody vegetation. 98 co cn co I i i I 27 H. (U) INITIATION AND DEVELOPMENT OF THE DEFOLIATION PROGRAM (U) From 1956 through 1964 approximately 12,000 chemicals were screened for herbicidal activity. Those that showed even the slightest defoliation or desiccation activity were put into the defoliant screening program that was initiated in 1962.QO (U) Dr. Minarik implemented the present U.S. Army Biological Laboratories Defoliation Program with the establishment of a synthesis and screening contract with Penhsalt Chemicals Corporation in July 1962,lOB also an inhouse screening for candidate defoliants. In April 1962loe he had negotiated a seedling tree contract with Bio-Search and Development Company Inc. to screen more than 600 chemicals that had previously shown biological activity in Crops Division screening programs. In the fall he established a tree nursery (8,000 trees comprising 18 species) at Fort Detrick. The program ^ expanded rapidly. l>&fQliaion Conferences were held at Fort Detrick in 1963,903 1964,107 and 1965108 so that- all contractors and government per sonnel who were working in support of the Defoliation Program could summa rize their findings, discuss their problems, and exchange ideas. 90 (U) Dr. Robert A. barrow had joined Crops Division in September 1962 after extensive experience in research in vegetation control at Texas A&M University. Be assumed the role of Chief, Chemical Branch, when he joined the Division Staff and in 1963 and 1964 served as Project Officer for the defoliation test program conducted in'Thailand under ARPA Order Number 423* 1. (U) In-House Screening of Chemicals in Earlier Tears (U) In the earlier years (1956 and 1957) William H. Preston, Charles R. Downing, and Charles E. Hess were involved with in-house screening of chemicals. They intensively screened 577 chemicals at Fort Detrick and Fort Ritchie, Maryland, for the best available defoliants, desiccants, and vegetation-control agents. After investigating environmental conditions, spray techniques, and formulations that increase the effectiveness of defoliants and desiccants, they found that 2-butyne-l,4-diol and tributyl phosphate were the most effective defoliant and desiccant. 1 0 1 Dr. S.R. HcLane and Edward W. Dean had previously reported (lSSS)9'* that tributyl phosphate produced a discernible mark on vegetation in less than 30 minutes, making it potentially useful in camouflage detection. HcLane also found that an area marked with 3 -amino-1 ,2 ,4-triazole could be detected more than 3 months after the spray application, indicating its potential usefulness in target marking. (U) When Charles E. Hess investigated the potentialities of cacodylic acid as an anticrop cge.nt," he reported that cacodylic acid was an agent of choice. 1 0 3 In 1959 and I960 Ray Taylorson was involved in synthesising various forms of this chtmi-jal.10* I 0 3 5 3 10 co 28 2. (U) Greenhouse Screening and Field Testing Programs (U) After the Defoliation Program was established, J. Ray Frank (Horticulturist, assigned to Crops Division 14 April 1961) headed the screening phase;. He with the assistance o Ralph E. Buschmann and Robert F. Morneweck1 0 9 conducted coordinate screening tests on 14-day-old-Black Valentine bean plants for defoliant, desiccant, or herbicidal activity of compounds shown to be active in the contractor screening program or in the six-plant primary screening program that Dr. DeRose conducted. In turn, compounds showing a moderate or higher level of activity as defoliants, desiccants, or herbicides in the 14-day bean test (1,410 compounds tested from August 1961 to June 1963) were subjected to secondary screening on woody plant stealings (8 , 0 0 0 trees used each year) in greenhouse tests, which J. Ray Frank also h e a d e d . A c t i v e compounds in this screening program on woody plant seedlings were carried into a field testing program* that Kenneth Demaree, Horticulturist, directed.9Qa 1 1 0 I. EARLY HISTORY OF THE ACTIVITIES OF THE BIOLOGICAL BRANCH (13) An intensive biological program had been initiated at the same time as the chemical program. In March 1944 a formal research program was instituted in the Biological Branch on Piricularia oryzae as a potential agent against rice, 4 ' 1 1 1 and in 1946 on Puccinia graninis trj-.icl. the pathogen causing stem rust of wheat. Research continued on other pathogens. ' 1 1 2 ' 1 1 3 1 i 4 A.L. Andersen, B.W. Henry, and E.C. Tullis studied factors affecting infectivity, spread, and persistence of . oryzae in greenhouse and field trials. Investigations on sporulation conducted by Andersen, Henry, V.W. Dorrell, and Edward Cherry led to the development of a process for producing spores of P. cryzac in mass quantities.4 111llla Henry and Andersen also investigated the use of wetting and adhesive agents to increase the effectiveness of conidial suspensions for plant inocu lations. 1 1 5 S.F. Snieszko, E.P. Lowe, and J.B. Carpenter not only inten sively investigated the development of Phytophthora infestans as a potential agent for biological warfare, but they also submitted improved methods for the cultivation and storage of . infestans. 1 1 4 R.H. Page, A.F. Sherfj and T.L. Morgan reported the effect of temperature and relative humidity on the longevity of the conidia of He imlnthosporium orvzae and studied, the factors affecting its infectivity. 1 1 3 1 1 3 With interest in the Orient waning after the end of the war with Japan, the rice blast (P. oryzae) work was terminated in December, 1947, and the progress on all aspects of the problem was summarized in a final report. 4 In the latter part of 1947, Dr. Ian W. Tervet* joined Crops Division s tAS f &s Chief of the Biological Branch, replacing Dr. Berch W. Henry,** who resigned In September 1947. Dr. Tervet, with Dr. Robert Cassell as * Presently Lecturer in Biology, Arizona State College, Flagstaff, Arizona. ** Presently Assistant Director, Southern Forest Experiment Station, Headquarters T-10210 Federal.Building, 701 Loyola Avenue, New Orleans, Louisiana 70113, telephone (504)527-6781. co cn co ,tu,'^U'ylw--~~ ^ "VSMr* 29 project leader, made actable progress during the period 1948 through the summer of 1951.116" 123 He and his colleagues developed and demonstrated methods for performing all critical steps such as culturing; 1 3 0 harvest ing, 1 1 6 * 1 2 1 * 1 2 2 processing, storing, and disseminating P. graminis tritici. Exper-iment-c-were-- being-carried-out- in'the field and greenhouse, and stem rust production vas under way in Crops Division's nev Pilot Plant (Building 374). Col. Theodore Odlmd had taken leave of absence from the University of Rhode Island where he was Head of the Agronomy Department* to head this project. ffiy After carrying out extensive research on P. gramlnis tritici at Camp Detrick, field tests were set up in Puerto Rico during the winter of 1950 to 1951 to demonstrate, the feasibilityoflarge-scale production. Success with tests in Puerto Rico resulted in a requirement from theM/Lit Force for the production and stockpiling of a substantial quantity of P. graminis tritici. .This procurement was assigned to Special Projects Division, Edgewood Arsenal, who directed six production sites in the midwest in the summer o f. 1951. Personnel from the Biological Branch of Crops Division gave technical advice and aided is establishing a facility for this requirement. (U) Dr. Tervet resigned in the sunnier of 1951 and was replaced by Dr. John E. Mitchell.** J. (U) PIONEER RESEARCH ON GIBBERELLIN (U) Before Dr. Mitchell joined Crops Division, Dr. Axel Andersen was working on Gibberella zeae as an agent for wheat and had acquired numerous cultures of related, fungi. 1 2 4 One culture, Fusarium moniliforme (Gibberella fulikuroi). was known to cause bakanae (foolish seedling) disease of rice. Dr. Andersen- cultured the organism and studied it while Dr. Minarik inves tigated the spent culture liquids for their ability to stimulate vegetative elongation of rice. It was believed that there were two materials In the spent culture liquids-- a stimulator and a toxic material. When Dr. Mitchell joined the staff on 1 July 1948, the latter task (isolation of biologically active materials) was turned over to him as his primary responsibility. (U) Crops Division was now carrying out the first research on gibberellln outside that in the Orient. 1 2 5 In 1912, Sawada, a Japanese plant pathologist, believed that the bakanae disease of rice was caused by a fungus. In 1926, Kurosawa, a co-worker of Sawada, published his now classical paper, "Experimental studies on 'the secretion of Fusarium heterosporium on rice plants." Dr. Kurosawa is credited with the "opening up of the fertile ; * Presently holds the same position in the College of Agricultural Science, University of Rhode Island, Kingston, Rhode Island 02881. * * Presently Professor, Plant Pathology Department, University of Visconsin, Hadisoa, Wisconsin 53706* Cl? co cn co cz> cn * in*:.' _ i - >> v- ; II \ 30 | gibberellin field." In 1935, Dr. Yabuta named the growth factor "gibberellin" 1 on the basis of the scientific name of the fungus, Gibberella fo iikuroi 1 (Saw.) Wr. Three years later he and Dr. Sumiki reported the isolation | of crystalline gibberellin A and B . 1 2 8 i (D) In March 1950, Dr, Mitchell gave a review of his work at the 7th Annual Meeting of the Potomac Division of the American Fhytopathological I Society held in the Plant Industry Station Auditorium, Beltsville, Maryland, { March 9 and 10. 1 2 7 After developing procedures for large-scale production t of gibberellin concentrates, Dr. Mitchell served as project officer on a contract (negotiated August 1951) with a PSDA, Peoria, Illinois, facility (Northern Regional Research laboratory) to produce gibberellin. Dr. Mitchell et al. had obtained a new gibberellin in crystalline form from a fermentation using Mitchell's organism (Mo. 624 * NRRL 2284) on glucose solution and i designated the new product as gibberellin X. (This new product was temporarily designated gibberellin X to distinguish it from Sumiki's natural gibberellins A and B and from his gibberellin C, a derivative of gibberellin A.) In June 1952, a successful 160-gallon fermentation had been run and crude crystalline gibberellin was obtained. On 1 July 1952 work was begun on contract with the* Chemical Corps, Camp .Detrick, to develop suitable methods for the production, isolation, and characterization of the gibber ellins, plant growth regulators produced by the fungus F. moniliforme (G,. fujikuroi) .1SS According to the Source Book on Gibberellin, 1828- < 1957, compiled by Dr. Frank Stodola of the U.S. Department of Agriculture,13Ba Dr. J.E. Mitchell in this country and Dr. P.W. Brian in England were the * first to point out the potentialities of the gibberellin compounds, leading to rapid and substantial progress on all aspects of the problem by workers in all parts of the world. K. f t STEM RUST After Dr. Mitchell became Chief of the Biological Branch in 1951, Dr. ^ 1 . Kingsolver joined the staff as leader of the rust project. Further significant improvements were made in cereal rust spore production techniques, 1 E 9 " 1 4 5 leading to the development of new agent-dissemination techniques. In cooperation with the USN Bureau of Aeronautics, Roy M. Acker and his assistants in Operational Requirements Branch demonstrated effectively the feasibility of the line-source delivery of dry agents with the Aero 1A and Aero 2A tanks.33 As a result of these demonstrations, this concept of agent delivery was widely accepted for C3R agent employ ment and was adopted throughout DOD. 1. ^ p e v e l o p m e u t of Equipment for Cereal Rust System ; An integral part of this development was the further design and fabj^Hcition of equipment and devices for all phases of the stem rust system. Dr. L.M. Massey, Jr., and Thomas L. Morgan developed methods for processing, packaging, and storing cereal rust spores. 1 3 7 (A search of the literature had produced no careful quantitative analysis of fungus tPUViUiiktffoSiSUiritl! 31 spore longevity in storage prior"to the initiation of their work.) Equipment (harvesters both for greenhouse and field) was fabricated as a joint activity of the Engineering Division and Crops Division. An historical account, with illustrations, of the various types of equipment used by Crops Division for harvesting cereal rust spores from host plants was written by Edward Cherry in Special Report 219-1.131 Field harvester development had progressed from a simple garden tractor (Field Harvester, Model 1) that collected 4 pounds of rust per acre in 194S to a selfpropelled machine harvester (Field Harvester, Model 4) that harvested as touch as 73.7 pounds per acre in 1933.131 2. Cereal Rust Production at Various Sites ' During the winter months of 1952 to 1953, C.H. Kingsolver, eld, William E. Miller, Robert G. Emge, Edward Cherry, Louis Massey, and Thomas Morgan were involved in experiments on cereal rust production in the Southwestern United States. 1 3 2 The following winter (1954 to 1955) some members of this team conducted tests at five sites in Puerto Rico and at one site In St. Croix, Virgin Islands. They recorded plant height, plant development, and .plant susceptibility to stem rust for 13 varieties at the various sites throughout the testing period.13S * 1 3 5 a (U) During the winters of 1954 through 1957, Dr, Kingsolver, John F. Underwood, and Clyde Feet conducted a series of experiments in St. Croix to evaluate the intensification and spread of wheat stem rust both within field stands and over a 10-mile grid. These experiments resulted in the formulation of a mathematical model characterising the spread potential of the stem rust organism. The exponential slope regres sion characterized the rate of rust intensification and, together with data on rust development prior to the exponential increase, could be used as a prediction system.13S^ *13Sc 3. (U) Development of Laboratory Assessment Techniques (U) Concomitantly at Camp Detrick, laboratory assessment of stem rust was being studied intensively. To improve the accuracy of assay , results, Massey and Morgan recommended certain modifications in methods of assessment. 1 3 3 Procedures for determining percentage total spores, per centage stem ruse of total spores, spore viability, and moisture were adopted as standard. 1 3 4 (D) By February 1955, Drs. Kingsolver, C.G. Schmitt, and E.L. Sharp reported research on the influence of controlled environmental conditions on the Infectivity of uredospores of cereal rusts. They found that hydration Increased chances for rust establishment by increasing percentage of spore germination and by decreasing the time required for maximum germination and appressoriuc formation. The benefits of hydration for enhancing infection ware proportionally greater with older spore lots than with younger and with i 32 shorter dev periods chan with longer. Primary leaves verie more susceptible to infection than were secondary or succeeding leaves. Uniform inoculations made on the adaxial leaf surface yielded more pustules than did those made on the abaxial surface. The minimum continuous moist-chamber temperature to initiate infection was near 33 F, the maximum near. 83 P, and the optimum _________ between 70 an d 7 r* F ._Minimum-mo4sj--chembr* period for infection at optimum temperature was 6 hours for nonhydrated spores. Temperatures exceeding j 90 F vapidly reduced infection potential of uredospores. Spores on plants I that received a dew period of 15 to 120 minutes before interruption of dew f at 60Z EH and 70 F decreased directly in infection potential with period f of dew prior to "drying" and resumption of dew period'.138 rt * [ (U) Concurrently, Drs, Schmitt, Sharp, Ball,.Miller, Bromfield, and * Kingsolver were developing techniques for assessing infectivity of cereal i rust spores. Relatively uniform spore distribution was attained by using a galvanized sheeting settling tower 4 feet high and 3 feet in diameter ' ' mounted over a plywood box with a rotating floor to facilitate loading and unloading and with a baffle to allow spore clumps to settle before exposing * leaves to the spore shower. A CC>2 pistol provided somewhat better spore ' distribution than did air pressure between 15 and 50 psi instantaneously released by a b o lenoid-actuated mechanism. .Leaves were exposed horizontally : to the vertically falling spores by the expedient of fastening them to ! metal backboards. Regulation of temperature andhumidity during the moist period was effected in specially constructed, thermostatically controlled * dew chambers that provided a range of temperature from 55 to more than 95 F. Aniline blue and acid fuchsin alone or in mixture with either lactc- phenol or chloral hydrate were effective in rapid staining methods to ; demonstrate rust mycelium in host tissues.1*0' L. (U) PRELIMINARY STUDIES ON LEAF RUST (U)."Complementary studies on leaf rust had been made previously (1950) to compare the behavior of this rust with the related stem rust. Kent Irish obtained significant information on the competition of races of the leaf rust organism. Preliminary studies indicated that competition was mani fest between closely associated Tacas growing in composite culture. -Four important races of leaf rust, 9, 15, 58, and 126, were mixed in equal amounts and grown together on the uniformly susceptible host variety Cheyenne, A decline and/or disappearance of a race from the association was considered to be evidence of competition with one or all of the races in the mixture. Composite culture I was carried through seven generations and composire culture II was continued through 10 generations. The race populations in each generation were sampled by making a series of single-pustule isolations. The Isolates vers cultured and the races identified. One hundred and three isolations were cade from the generations of culture I and 158 from those of culture II. Physiologic races 9 and 15 were the dominant competitors when grown with races 58 and 126.123 CD C x 'i t-T l CD } CD I i 23 : H. (U) EARLY WORK ON FLANT VIRUSES (D) Investigations on the bud-biight disease of soybeans caused by the tobacco and tomato ring-spot viruses were conducted by Dr. Frances M. . Lacterell from 1950 to 1952.* Upon her reassignment to the rice project, virus studies were continued by Dr. P.R. Desjardins (lit.)** and Dr. Robert P. Kahn.*** Plant viruses considered as candidates for BW agents at this time were limited to mechanically transmitted viruses (as opposed to insecttransmitted) because of the anticipated problems in transporting viruliferous insects with retention of viability of both host and agent. Lt, R.C. Carter, an entomologist, spent his tour of duty (1954-1955) compiling a literature survey on the feasibility of using insect-transmitted plant viruses as BW agents.**** Dr. Kahn was assisted by Lt. Thomas C. Allen, Jr. and Pvt. Q.J. Dickerson in his virus work. . (U) Dr. Mitchell continued as Chief of the Branch until July 1955, when it was divided into two branch , Biological Branch 1 and Biological Branch II. He headed Biological Branch I and directed research on rice and potato pathogens and plant viruses. Dr. Kingsolver became Chief of Bio logical Branch II, directing research on the cereal'rusts. # ; i i 1; N. (U) DEVELOPMENT OF A SYSTEM F O R RICE 1. (U) Field Studies (U) In 1952, investigations on rice blast (Piricularia oryzae) and brown spot l rice (Kolminthospnrium oryzae) were reinstated in the Crops Division piogram under Dr, E.C. Tuilis as Project Leader. Dr. T.W. Johnson, Jr., was assigned to study P. QTvzao, and Dt. Letterell, H. oryzae. During that year, inocula of both rice pathogens were prepared by laboratory culture, and field tests were conducted in Texas, Arkansas, and Mississippi, The Inoculations yielded minimal success for reasons relating to quality of inoculum, plant age, and weather. Inoculations of P. oryzae planned for plots in the new rice-groving areas in the Florida Everglade region in this first year were not completed because of the natural development of a severe epiphytotic of rice blast. Investigations on H. oryzae were termi nated in the latter part of 1952 because the field trials and greenhouse tests showed that this agent could be effective only on pre-eoerged or young seedlings, or on plants grown in poor soils having low nitrogen or unbalanced nutrition.***** The severity of the natural outbreak of blast * Reference 67, page 141. ** References 62, 64, and 66, jpages 140 and 141. *** Inferences 64, 66, and 67, pages 140 and 141. **** Reference 15, page 136. ***** Johnson, T.W., Jr.j Lattereil, F.M.; Tuilis, E.C. 1952. Field tests of rice pathogens, (typewritten repert). Crops Division, Camp Detrick, Frederick, Maryland, CD CO R. f t ANALOGUE AREA STUDIES (U) During' this interim (1958), a state-of-the-art evaluation indicated a need for additional quantitative data on the effectiveness of the wheat TEem" nTs't'~agent-- itfclimati'E' analogues- of'possible targets. After Crops Division was reactivated and the mission vas reinstated in 1959 (the Division was in process of staffing its operation from 1959 to 1962), an intensive test program was planned and initiated (in 1960) under the supervision of Kent R. Irish.184 Because of the numerous uncontrollable variables, it was recommended that 5 years' testing be conducted to accumulate meaningful data. The first tests that involved analogue areas had been conducted by Rogqf ti. Hartmeyer, Kent R. Irish, Shosuke Goto, William B. Johnson, Wilton' R. Tenney, and George N. Asal under the supervision of R.H. -Acker at Rosemount Research Center, Rosemount, Minnesota, and at the adjoining Rosemount Agricultural Research Center. The USN Jet Fighter Cutlass F7U-3 vas used in these experiments and results from 1955 to 1957 shoved that cereal rust epidemics could be induced in analogue areas that would result in complete destruction of a cereal crop.185 (U) After the reactivation of Crops Division, analogue tests were con tinued under an agreement with the IJSDA, who provided sites and crops at selected analogue areas. The first series of tests after reactivation were conducted in 1960 at Hays, Kansas, and, Langdon, North Dakota,184 where four 1-acre plots were inoculated with various amounts of stem rust spores. These tests were designed to delineate the major factors contributing to the development of destructive rust epidemics in the central United States. Extensive data were collected on rust increase and development, crop development, meteorology,* and effect of rust on crop yield. (U) The program vas accelerated in 1962 to Include a greater number of "locations and more detailed study of rust increase, micremeteorological factors, and yield reduction at each location.187 Under Dr. Kingsolver's leadership (he resumed his role as Chief, Biological Branch, 17 September 1962), William B. Johnson and Dr. Roland F. Line conducted tests at Still water, Oklahoma, and Hays, Kansas, in 1963;187 then in 1964 the tests ware expanded to include six locations and two to -11 plots in each area. That * Of special interest was the amount of dew and its duration that W 2 S measured by the Taylor dew meter, an instrument that records with high accuracy the starting time and the duration of dev deposits (application for patent filed by the Federal C'-vcmment in Hay 1953 under title "Dev Meter").106 Dr. Carlton F. Taylor had invented Lhit device (an invalu able instrument used to date, 1970) in the course of research on potato diseases. Edw.vd Cherry (deceased), Raymond Crum (deceased), and Dr. John Smoot (presently Research Flant Pathologist, Market Quality Research Division, Agricultural Research Service, United States Depart- C 3 ment of Agriculture, 2120 Camden Road, Orlando, Florida 32789) also OJ> ' participated in its development from the basic idea to the present .c_n .model.186 c_o  38 year Dr. Line and Clyde E. Eeet conducted field tests at the following locations: Stillwater^ Oklahoma;188 Hays, Kansas;188 Crookston, Minnesota;les and Casseltorr80 and Langdon, North Dakota.191 The inoculum (mostly race 56 of wheat stem rust) was varied in dosage from plot to plot to produce a range of primary infections. Also portions of each plot were protected from disease by fungicides to serve as controls in assessing yield reduction. (U) In Hays, Kansas, from 1960 to 1965, Line, Peer, and Kingsolver studied the epidemiology of stem rust in fields of Cheyenne wheat that had been Inoculated wj th u redos pores of race 56 when the plants were in tillering to boot stages of growth. Infection occurred in 6 consecutive years. Severities at soft dough were about 30, 25, 7, 2, 2, and 20Z; yields for rusted plots were 20, 19, 25, 34, 22, and 18 bushels per acre; and yields for adjacent control areas were 46, 29, 45, 35, 29, and 62 bushels per acre, 'respectively. In 1965,' a natural epidemic of stem rust caused severe -* damage to wheat in Kansas and Nebraska. In 1965, the crop ripened late in the season. In 5 of the 6 years, weather was favorable for rust epidemics. Late natural infection appeared to be the primary factor limiting severity of the rust epidemics.192 (U) Further research in Crops Division-- Plant Sciences Laboratories during FY 1965-1967, 1968, and 1969 is discussed in Sections II, III, and IV. i r* .? in Florida, on the other hand, encouraged greater emphasis on the study of \ blast. This outbreak occurred in plantings of varieties that had been considered resistant to blast on the basis of their reactions in Arkansas, 7------------- and-*thtxsr-prov"i`ded" crtrirums'tantTal'- evidence o f p h y s io lo g ic a l s p e c ia liz a t io n J in the rice blast pathogen. (U) Another outbreak of blast occurred in commercial rice plantings * In the Belle Glade area in 1953.146 Dr. R.D..Schein (CFL), Dr. Tullis, f and other members of the staff observed the progress of the disease from | 15 June to 25 September. Severe damage occurred in all fields planted in muck soil, both upland and flooded. Severity of infection subsided during i late tillering stages, but increased during panicle development in most : fields. The occurrence of this epiphytotic afforded an opportunity for I firsthand study of the potentialities of the pathogen as a BW agent aud of ; the conditions requisite for disease development.146 The following, year (work completed October 1954), Dr. Schein and Dr. R.B.* Corey (enlisted i Specialist of the U.S. Army), with the cooperation of personnel of the i Everglades Experiment Station, induced an epiphytotic of the blast disease in rice growing under highly atypical soil conditions. It was started from inoculations in plots 0.036 acre and spread over more than 10 acres in 4 weeks* time. The increase in disease resulting from application of nitrogen fertilizers to the sand land was indicative of the potential effect of this nutrient element on blast development. The marked surge in disease development, followed by a definite regression of inlensity, illustrated the need for more adequate knowledge concerning the effect of meteorological conditions on disease development and the need for an experimental site with soil more typical of rice-growing land.147 2. (U) Etiology of Rice Blast (U) With the increased interest in rice blast following the severe epiphytotics in Florida, Dr. Latterell was reassigned to study the cultural and pathogenic characteristics of the causal fungus, P. o ryzae. Dr. Kahn * was detailed from the virus project to study the factors influencing in fection by the blast pathogen. As noted above, the varieties of rice affected in the Florida fields indicated that there probably existed more than one pathogenic strain of oryzae. Experiments were undertaken to \ determine whether such was the case by inoculating four varieties of rice with two strains of the pathogen: one from the 1952 epiphytotic and a 1943 isolate from Arkansas. The two isolates caused opposite responses ; from each of the four varieties: the Florida isolate was pathogenic to Zenith and Rexoro, but not to Lacrosse and Caloro; the Arkansas isolate, showed the reverse pattern. These patterns of reaction appeared to be characteristic and consistent for both isolates, and thus provided the first experimental evidence of the existence of at least two strains of P. -- , . oryzae.*46 In October, 1953, Dr. Latterell initiated a screening program o' with se*,eral general goal: (i) to determine to the extent possible the r_j~i degree of pathogenic variation or ''physiologic specialization*' that occurs v_* \ among isolates of P. orvzat to be collected from different hosts and many __ l rice-growing areas of the wor3.d; (ii) to select through intensive testing __ .'A .j -3 .;-n.* -* 35 a group of varieties that by their reactions would provide clear-cut differ entiation among the various races encountered among the collections; and (ill) to determine the capability of th Isolates acquired for attacking varieties known or likely to be grown in potential target areas by screening a large number of varieties to the most broadly pathogenic races. As. isolates were collected from various parts of the world and tested for pathogenicity, it became apparent that this fungus was extremely variable, and that the species comprised a number of "races" that differed in their ability to attack certain varieties of rice.1*9 (U) The data from 3 years' testing (1954 to 1957) involving more than 1,000 isolates of P. oryzae and several hundred varieties of rice were summarized in a report published in 1959.150 Dr. Latterell had selected ten varieties of rice as best among all those tested for characterizing the 15 physiologic races that she had identified up until that time.-50 In a 1960 publication151 presenting evidence for the existence-of physiologic races characterized by their ability to attack rice varieties differentially, a scale of lesion types was proposed to delineate the range `of response encountered among the different varieties, and a chart presented showing the response of the 10 differential varieties to the 15 races. (U) By Pebrupry 1956, Dr. Robert P. Kahn completed a study, under controlled environmental conditions, of factors influencing the infection of rice by the blast fungus.152 He continued working with this pathogen under controlled conditions, investigating the effects of temperature, moisture, age, rice cultural conditions, and/or light on appressorial development, the relative susceptibility to infection of different varieties, lesion incubation period, race of lesion elongation, and relative specu lation.153 During the first phase of work, PFC Jack Collier, PTC- John Libby,'and 1LT James Kato assisted Kahn in the plant inoculations and lesion counts. During Che second phase, LT. Thomas C. Allen, Jr., and PVT O.J. Dickerson assisted in the research. Kahn submitted data on the third phase in April 1958, his final report of investigation on infectivity studies.154 (U) Dr. Mitchell resigned in August 1956 and Dr. Chris G. Schmitt assumed responsibilities as Chief of Biological Branch II. 0. (D) DEVELOPMENT OF MOBILE UNITS FOR RUST SPORE ANALYZING, PROCESSING, AND PACKAGING (U) In December .1955, a proposal was submitted to the U.5. Army Chemical Corps Materiel Command for improvements in processing, harvesting, and storage equipment in connection with an anticrop agent. One of the phases of the proposed program was the design and development of mobile units for C D analyzing, processing, and packaging the agent. That part of the IndusLrialco Preparedness Measure (IPM) concerned with the mobile units was approved, c_n and work was initiated on their development during 1956. The units were cd obtained from Ross Ordnance Depot and delivered 9 November 1956. With the -- 36 tti ' i. ] cooperation of Engineering Research Division, personnel fitted the two i semitrailers (34-foot van-type) as mobile units, one a laboratory, the t other a processing unit, for processing and packaging the anticrop agent at : the production site. These units were completed and turned over to Crops T Division for preliminary testing in August 1957. Thomas Morgan, project } leader, tested each project item as it vas developed. For his outstanding ; service during the development and testing of the mobile labs,139 the large- ; capacity storage containers, and the X5A harvester,, all of which contributed f significantly to greater efficiency of agent production, the Department of | the Army awarded him a "Special Act or Service Award" (21 March 1961).1393 i Edward Cherry received a "Special Act or Service Award" on the same date [ for his contribution, the perfecting (with the cooperation of Engineering Research Division) of the X5A harvester. After Morgan's final testing and acceptance of the units in the summer of 1958,139 the units were shipped to Puerto Rico for use during stem rust experiments that Edvard Cherry and Lester Boyer headed from 1958 to 1961.155 . P. (U) INHIBITOR STUDIES (U) Other phases of research on P_. graminis triti ci in the laboratory .and greenhouse were: some physical and chemical properties of a volatile fraction from uredospores affecting their germination and development;155 pelargonaldehyde as an endogenous germination stimulator of wheat rust spores;15' interaction of aldehydes with uredospores Df stem rust of wheat;15B the effect of DDT on the rust reaction of several wheat varieties to wheat stem rust;159 "the use of controlled temperature and selected hosts to differentiate between two cultures of wheat stem _rust;lao some critical factors involved in establishment e,I\ graalnis-.151 and determination of effects of different temperatures on uredial infection with P. graminis tritici.152 Q. (U) PHASE-OUT (U) Most of the activities of Crops Division ceased when the Department 1 of the Army terminated the primary function of the Division 31 December 1957. Eight professionals* (of 118 personnel) and three nonprofessiohals** were retained to complete reports of work92B9-i3i35i39 ,iso,is3,i6*,iE9-ie3,iss and carry on research at a token level. IPH funds were used to improve equipment such as the mobile units and type-classified agent systems.1393 0 3 5 3 112 * Dr. Charles E. Minarik, Dr. Frances M. Latterell, Dr. William E. Miller, Mr. Kent R. Irish, Mr. Thomas L. Morgan, Mr. William B. Johnson, Mr. Lester U. Boyer, and Mr. Edward Cherry. ** Mrs. Carolyn M. Walker, Mr. Melvin E. Krantz, and Mr. Charles M. Bierly (deceased 17 August 1968).