Special Collections Department
403 Parks Library
Iowa State University
Ames, IA 50011-2140

RS 9/18/51
E. P. Sylwester (1906-1975)
Papers, 1936-1971, n.d.


Descriptive summary

creator:

Sylwester, E. P. (1906-1975)

title:

Papers

dates:

1936-1971, n.d.

extent:

7 linear feet (26 document boxes)

collection number:

RS 9/18/51

repository:

University Archives, Special Collections Department, Iowa State University.

 

Administrative information

access:

Open for research

publication rights:

Consult Head, Special Collections Department

preferred citation:

E. P. Sylwester Papers, RS 9/18/51, Special Collections Department, Iowa State University Library.

 

Biographical note

Erhardt Paul (E. P.) Sylwester was born to John and Justina (Stelter) Sylwester on January 19, 1906, in Gaylord, Minnesota. He Received his B.A. (1930) from St. Olaf College and his M.A. (1931) and Ph.D. (1945) from Iowa State University. Sylwester taught at St. Olaf College, but spent most of his professional career at Iowa State. In 1935 Sylwester received an appointment with Iowa State Extension, where he worked for thirty years as an extension botanist and plant pathologist. He specialized in weed control, especially promoting cultural methods. He served as head of the Iowa State Seed Laboratory from 1946-1952. Sylwester helped found the North Central Weed Control Conference and served as president in 1950. He was the national chair of the Association of Regional Weed Control Conference in 1952-1953. He received numerous awards, including a Distinguished Faculty Citation from Iowa State in 1969.

 

Collection description

This collection (1936-1971, n.d.) contains a biographical sketch of Sylwester, his correspondence (1936-1970), Sylwester publications and manuscripts (1942-1955), clippings (1917-1977), committee files (1945-1971), agreements (1932-1960), reports and surveys (1926-1963), subject files (1898-1971), class notes (1926-1937), photographs, and sound recordings. Correspondence is primarily related to inquiries regarding weeds and plant diseases in Iowa, but also includes requests from other states and international inquiries. Material and pamphlets related to wildlife, farm safety, and weed control are in the collection as well. Among the manuscripts is a draft of Louis H. Pammel's weed survey of Iowa, which Sylwester co-edited. Other manuscripts related to weed control written by Sylwester are in the collection. Much of the material is ephemera collected by Sylwester related to botany and natural sciences. Clipping files concern Barberry; 2, 4-D; "Bargain Seeds"; and clean seeds. Collection also includes sound recordings related to weed control.

 

Organization

The collection is listed alphabetically.

 

Container list

Box

Folder

Title

Dates

1

1

Biographical information

n.d.

1

2

Correspondence – greeting cards and post cards

1949-1969

1

3

Correspondence – incoming regarding queries on weed control

1936-1970, n.d.

1

4

Correspondence – Personal

1936-1970, n.d.

1

5

Correspondence – Professional

1936-1970

1

6

Correspondence – Missouri

1954-1955

1

7

Correspondence – Nebraska – Plant Pathology

1954-1955

1

8

Correspondence – Nevada

1954

1

9

Correspondence – North Carolina

1955

1

10

Correspondence – New Jersey

1954-1955

1

11

Correspondence – New York

1954-1955

1

12

Correspondence – North Dakota

1954-1955

1

13

Correspondence – Ohio

1954-1955

1

14

Correspondence – Pennsylvania

1954-1955

1

15

Correspondence – South Dakota

1954-1955

1

16

Correspondence – Tennessee

1954

1

17

Correspondence – Texas

1953-1955

1

18

Correspondence – Utah

1953-1954

1

19

Correspondence – Washington, D.C. General

1954-1955

1

20

Correspondence – Wisconsin

1954-1955

1

21

Correspondence – Canada

1953-1955

1

22

Correspondence – British Columbia

1953

1

23

Correspondence – Denmark

1955

1

24

Correspondence – South America

1954

2

1

Correspondence – Plant Disease (A-C)

1952-1953

2

2

Correspondence – Plant Disease (D-G)

1952-1953

2

3

Correspondence – Plant Disease (H-M)

1952-1953

2

4

Correspondence – Plant Disease (O-W)

1952-1953

2

5

Correspondence – Plant Disease (outside Iowa)

1952-1953

2

6

Correspondence – Weed Seeds (Ad-Au)

1951-1953

2

7

Correspondence – Weed Seeds (Be-Br)

1952-1953

2

8

Correspondence – Weed Seeds (Bu)

1951-1953

2

9

Correspondence – Weed Seeds (Ca)

1952-1953

2

10

Correspondence – Weed Seeds (Ce-Ch)

1952-1953

2

11

Correspondence – Weed Seeds (Ch-Cr)

1952-1953

3

1

Correspondence – Weed Seeds (Da-De)

1952-1953

3

2

Correspondence – Weed Seeds (De-Du)

1952-1953

3

3

Correspondence – Weed Seeds (Em)

1952-1953

3

4

Correspondence – Weed Seeds (Fa-Fr)

1952-1953

3

5

Correspondence – Weed Seeds (Gr-Gu)

1952-1953

3

6

Correspondence – Weed Seeds (Ha)

1952-1953

3

7

Correspondence – Weed Seeds (He-Hu)

1952-1953

3

8

Correspondence – Weed Seeds (Id-Io)

1952-1953

3

9

Correspondence – Weed Seeds (Ja-Jo)

1952-1953

3

10

Correspondence – Weed Seeds (Ke-Ko)

1952-1953

3

11

Correspondence – Weed Seeds (Le-Li)

1952-1953

3

12

Correspondence – Weed Seeds (Lo-Ly)

1952-1953

4

1

Correspondence – Weed Seeds (Ma)

1952-1953

4

2

Correspondence – Weed Seeds (Mi-Mu)

1952-1953

4

3

Correspondence – Weed Seeds (O)

1952-1953

4

4

Correspondence – Weed Seeds (Pa-Po)

1952-1953

4

5

Correspondence – Weed Seeds (Po)

1952-1953

4

6

Correspondence – Weed Seeds (Po)

1952-1953

4

7

Correspondence – Weed Seeds (Po)

1952-1953

4

8

Correspondence – Weed Seeds (Ri-Sa)

1952-1953

4

9

Correspondence – Weed Seeds (Sc-St)

1952-1953

4

10

Correspondence – Weed Seeds (Ta)

1952-1953

4

11

Correspondence – Weed Seeds (Un-Va)

1952-1953

4

12

Correspondence – Weed Seeds (Wa)

1952-1953

4

13

Correspondence – Weed Seeds (We)

1952-1953

5

1

Correspondence – Weed Seeds (Wi)

1952-1953

5

2

Correspondence – Weed Seeds (Wo-Wr)

1952-1953

5

3

Correspondence – Weed Seeds (outside Iowa)

1952

5

4

Correspondence – Weed Seeds (outside Iowa)

1953

5

5

Correspondence – Weed Seeds (Canada)

1952-1953

5

6

Publications – 2,4-D, Weed Control (Open forum of the Sunday Register)

n.d.

5

7

Publications – Chemical Weed Control

1949

5

8

Publications – Common Poisonous Weed Enemies

1955

5

9

Publications – Educational Problems in Weed Control

1948

5

10

Publications – The Iowa Weed Law

1951

5

11

Publications – Modern Weed Control

n.d.

5

12

Publications – Questions and Answers on Weed Control

n.d.

5

13

Publications – Spraying – Babyhood to Manhood in 5 years

n.d.

5

14

Publications – Top-killing Alfalfa For Seed Production

1951

5

15

Publications – Weed Control

1949- 1950 ca.

5

16

Publications – Weed Control – Garden

1948-1949, n.d.

5

17

Publications – Weed Control – Lawns

1950 ca.

5

18

Publications – Weed Control – Noxious Weeds, Chick-weeds

1951-1955

5

19

Publications – Weed Control – Pasture

1951, n.d.

5

20

Publications, Talks – Weeds and Weed Control

n.d.

6

1

Publications – Weed Control – Roadside Spraying

1948-1950

6

2

Publications – Weed Control – Seed Treatment

1942-1950

6

3

Publications – Wild Hemp (Cannabis sativa L.)

n.d.

6

4

Committees – 4-H Club Essay Scholarship Committee

1952-1955, n.d.

6

5

Committees – Albia Pasture Committee

1954

6

6

Committees – Cemetery File

1960-1962, n.d.

6

7

Committees – Cooperative Extension Work

1943-1944, n.d.

6

8

Committees – Epsilon Sigma Phi

1955-1957, n.d.

6

9

Committees – Epsilon Sigma Phi – Note from Recognition Committee

1952-1963, n.d.

6

10

Committees – Farm Safety Committee

n.d.

6

11

Committees – Farm Safety Committee

1945-1956

7

1

Committees – Farm Safety Committee

1957-1960

7

2

Committees – Farm Safety Review

1950-1961

7

3

Committees – Farm Safety Week

1955-1960

7

4

Committees – Future Meetings – NCWCC

1953-1960

7

5

Committees – Memorial Resolution – J.E. Sass

1971

7

6

Committees – Midwest Agricultural Chemicals Assn.

1961

7

7

Committees – Plant Industry Group

1951-1960

7

8

Committees – Program Development

1954, n.d.

7

9

Committees – Seed Laboratory Committee Meetings and Correspondence

1945

7

10

Committees – USDA Recognition

1961-1962, n.d.

7

11

Agreements – Memorandum of Understanding between Agriculture and Home Economics Extension Service ISU and American Cyanamid Company

1959 ca.-1960

7

12

Agreements – Project Agreements

1932 ca.-1954

7

13

Agreements – Proposed Revision of Project Agreements

1960, n.d.

7

14

Reports and Surveys – Barberry Eradication Campaign, Iowa, Annual Report

1929

7

15

Reports and Surveys – Extension Manuscript Report of Review Committee

1949

7

16

Reports and Surveys – Farm Accidents

1947-1956

7

17

Reports and Surveys – Committee on Integration of Work between the College and USDA

1939-1940

7

18

Reports and Surveys – Committee on Relations with State Department

1939-1940

8

1

Reports and Surveys – Minneapolis Extension Conference

1950

8

2

Reports and Surveys – Committee on Striga Sp.

1957

8

3

Reports and Surveys – Housing Committee

1931-1935

8

4

Reports and Surveys –Trip to Third Pan-Pacific Science Congress

1926-1927

8

5

Reports and Surveys – Seed Viability

n.d.

8

6

Reports and Surveys – Sod and Nod

1950

8

7

Reports and Surveys – Twelfth Annual Report of Northern Iowa Agricultural Experiment Association

1942

8

8

Reports and Surveys – Weed Commissioner

1953-1956, n.d.

8

9

Reports and Surveys – Weed Commissioner

1957-1959

8

10

Reports and Surveys – Weed Commissioner

1960-1963

8

11

Reports and Surveys – Weed Survey of Iowa (I)

1931

9

1

Reports and Surveys – Weed Survey of Iowa (II)

1931

9

2

Reports and Surveys – Weed Survey of Iowa (III)

1931

9

3

Reports and Surveys – Weed Survey of Iowa (IV)

1931

9

4

Subject – 2,4-D Injury

1952-1962, n.d.

9

5

Subject – 2,4-D Weed Killer

1953-1966, n.d.

9

6

Subject – Algae Control

1954-1959, n.d.

9

7

Subject – Audubon Society (Des Moines)

1945

9

8

Subject – Bacterial Disease - Crown gall

1932

9

9

Subject – Birds

1928-1950

10

1

Subject – Bliss Material

1952-1955, n.d.

10

2

Subject – Brayton Chemicals

1955-1965

10

3

Subject – Brush Cutters

1953-1954, n.d.

10

4

Subject – Conservation

1933-1951, n.d.

10

5

Subject – Daily Summary – USDA Publications

1953-1957

10

6

Subject – Diseases of Livestock

1928-1956, n.d.

10

7

Subject – Elms

1961-1962, n.d.

10

8

Subject – Evergreen Windbreaks

1914-1940

10

9

Subject – Farm

1944-1950, n.d.

10

10

Subject – Farm and Home Practices and Labor Saving Methods

1943

10

11

Subject – Fence Posts – Preservative Treatments

1938-1944

10

12

Subject – Ferns of Iowa

1929-1950

10

13

Subject – Fish Recipes

1944-1952

10

14

Subject – Fishponds

1936-1951

10

15

Subject – Fishponds – USDA Publications

1936-1983

11

1

Subject – Forest

1934-1953

11

2

Subject – Forest Pathology

1938-1950

11

3

Subject – Forestry – USDA Publications

1933-1948

11

4

Subject – Fungi of Iowa

1921-1951

11

5

Subject – Game Birds

1936-1943, n.d.

11

6

Subject – Game Management on the Farm

1936-1940

11

7

Subject – Hemp

1937-1943, n.d.

11

8

Subject – Herbs

1935-1941, n.d.

12

1

Subject – Honey Producers

1936-1955, n.d.

12

2

Subject – Iowa Conservationist

1942-1961

12

3

Subject – Iowa State College Publications

1938-1947

12

4

Subject – Iowa Weed Law

1951 ca., n.d.

12

5

Subject – Iowa's State Parks

1932-1941, n.d.

12

6

Subject – Johnson Glass

1957-1966, n.d.

12

7

Subject – Landscape Plan

1941-1948, n.d.

12

8

Subject – Publications List of ISC Staff Members

1951

12

9

Subject – Losses Due to Weeds

1957

12

10

Subject – Magnetic Separators – Eriez Company

1952, n.d.

12

11

Subject – Mammals

1929-1949

12

12

Subject – Medicinal Plants

1940-1964

12

13

Subject – Medicinal Plants – USDA Publications

1921-1941, n.d.

13

1

Subject – Medicinal Plants – USDA Publications

1949-1960

13

2

Subject – Metropolitan Life Insurance Company Publications

1934-1939, n.d.

13

3

Subject – Miscellaneous – USDA Publications

1927-1958

13

4

Subject – Multiflora Rose

1949-1963, n.d.

13

5

Subject – Mushrooms

1928-1955

13

6

Subject – Nature Material

1952-1962, n.d.

13

7

Subject – Newsletter

1946-1971

13

8

Subject – Ornamental Trees

1931-1938

13

9

Subject – Plants

1905-1946, n.d.

13

10

Subject – Plant Diseases – Common Barberry and Black Stem Rust

1922-1951, n.d.

13

11

Subject – Plant Diseases – Ergot and Smuts

1934-1955, n.d.

13

12

Subject – Poisonous Plants

1925-1957, n.d.

13

13

Subject – Poisonous Plants – Colorado State College

1937-1950

13

14

Subject – Poisonous Plants – Nevada, University of

1920-1931

14

1

Subject – Poisonous Plants – New Mexico College

1929-1936

14

2

Subject – Poisonous Plants – North Dakota Agricultural College

1931-1935

14

3

Subject – Poisonous Plants – Purdue University

1914-1930

14

4

Subject – Poisonous Plants – Texas Agricultural Experiment Station

1931-1944

14

5

Subject – Poisonous Plants – USDA Publications

1898-1958

14

6

Subject – Poisonous Plants – Wyoming, University of

1913-1940

14

7

Subject – Poisonous Weeds – (A-M)

1903

14

8

Subject – Poisonous Weeds – (P-W)

1903

14

9

Subject – Poisonous Weeds Cause Livestock Hazards

n.d.

14

10

Subject – The Seed Laboratory

n.d.

14

11

Subject – Seed Treatment and Testing

1914-1951, n.d.

14

12

Subject – Seed Viability, Effect of Manure, Compost and Silage on

1944 ca.

14

13

Subject – Snakes

1926-1952

14

14

Subject – The State of Iowa

1940-1945

15

1

Subject – Striga Disease

1956, n.d.

15

2

Subject – Striga Disease

1957

15

3

Subject – Striga Disease

1958-1966

15

4

Subject – Teasel

1962-1965, n.d.

15

5

Subject – Top-killing Alfalfa for Seed Production

1941 – 1951 ca.

15

6

Subject – Trees

1914-1950, n.d.

15

7

Subject – Trees and Shrubs

1930-1944

15

8

Subject – Trees – USDA Publications

1929-1948

15

9

Subject – Turtox News

1930-1933

16

1

Subject – Usefulness of Birds on the Farm – USDA Publications

1922-1939

16

2

Subject – Weed and Brush Control

1946-1951

16

3

Subject – Weed Burners

1955 ca.-1957, n.d.

16

4

Subject – Weed Control

1935-1955

16

5

Subject – Weed Control – Botany 216

n.d.

16

6

Subject – Weed Control – Counties

1949 ca.

16

7

Subject – Weed Control – Highway and Fence Row

1958

16

8

Subject – Weed Control – Roadside Spraying

1950

16

9

Subject – Wild Flowers

1932-1953, n.d.

16

10

Subject – Wildlife Conservation

1936-1951

16

11

Subject – Woodland and Lumber

1936-1954, n.d.

17

1

Subject – Woodland and Lumber – USDA Publications

1928-1945, n.d.

17

2

Subject – General (Includes Nominees for Extension Recognition – Iowa World Index Map to NRC Coded Areas, "The Use of Copper Sulphate in Control of Microscopic Organisms," Report of County Agricultural Project Exhibits Committee)

1918-1939, n.d.

17

3

Subject – General (Includes "Response of Certain Legumes to Variations in Soil and Microclimate on Eroded Areas in Southeastern Iowa, Scientific American, Iowa Veterinarian)

1945-1970

17

4

Class Notes – Algae Extras

n.d.

17

5

Class Notes – Bacteriology 208a, 208b

1926-1933

17

6

Class Notes – Corn Kernel, Structure (Botany 138)

1931 ca.

17

7

Class Notes – Crop Breeding (Farm Crops 504)

1927

17

8

Class Notes – Cytology

1933

17

9

Class Notes – Dendrology and Ecology (Botany 420a)

1929

17

10

Class Notes – E.P. Sylwester – Bacteriology Notes

1931

17

11

Class Notes – Enzymes

1930 ca.

18

1

Class Notes – Farm Crops 104

1931 ca.

18

2

Class Notes – General Botany

n.d.

18

3

Class Notes – Genetics 122

1933

18

4

Class Notes – Genetics 130

1933

18

5

Class Notes – How Plants Make Food, Reproduce and Grow

n.d.

18

6

Class Notes – Organic Chemistry

1930

18

7

Class Notes – Pathology (Bacterial Diseases)

1926

18

8

Class Notes – Pathology (Disease Resistance)

1930 ca.

18

9

Class Notes – Plant Diseases

1935-1944, n.d.

18

10

Class Notes – Plant Histology (Botany 141)

1930

18

11

Class Notes – Plant Physiology (Botany 202)

1930

18

12

Class Notes – Seed Viability (Botany 445)

1937

19

1

Class Notes – Seeds

1931

19

2

Class Notes – Thallophyta

1930

19

3

Class Notes – Weeds (Botany 490)

1931 ca.

19

4

News Clippings – Barberry -

1917-1922

19

5

News Clippings – Barberry – Iowa Barberry clippings

1925-1932, n.d.

19

6

News Clippings – Barberry – Iowa Barberry clippings

1925-1932, n.d.

19

7

News Clippings – Barberry – Iowa Barberry clippings

1925-1932, n.d.

19

8

News Clippings – Barberry – Iowa Barberry clippings

1925-1932, n.d.

20

1

News Clippings – Barberry – Iowa Barberry clippings

1933-1938

20

2

News Clippings – Barberry – Iowa Barberry clippings

1933-1938

20

3

News Clippings – Barberry – Iowa Barberry clippings

1933-1938

20

4

News Clippings – Barberry – Iowa Barberry clippings

1933-1938

20

5

News Clippings – Barberry – Iowa Barberry clippings

1933-1938

20

6

News Clippings – Barberry – Iowa Barberry clippings

1933-1938

21

1

News Clippings – Barberry – Iowa Barberry clippings

1939-1957

21

2

News Clippings – Barberry – Iowa Barberry clippings

1939-1957

21

3

News Clippings – Barberry – Iowa Barberry clippings

1939-1957

21

4

News Clippings – General – 2,4-D

1950

21

5

News Clippings – General – "Bargain" Seeds

1967

21

6

News Clippings – General – Clean Seed

1955

21

7

News Clippings – General – Clean Seed is Vital to Weed Control

1954

21

8

News Clippings – General – Crabgrass Control

1961

21

9

News Clippings – General – E.P. Sylwester – Speaker at Meeting

1950

21

10

News Clippings – General – E.P. Sylwester – Speaker at Meeting

1955

21

11

News Clippings – General – Elm Disease

1966

21

12

News Clippings – General – Elm Disease

1966

22

1

News Clippings – General – Elm Disease

1977

22

2

News Clippings – General – Ergot Infection

1962

22

3

News Clippings – General – Fall Good Time to Spray Weeds

1950

22

4

News Clippings – General – Four Chemicals Help Control Weeds in Corn

1962

22

5

News Clippings – General – Good Weed Control By Iowa's Farmers

1962

22

6

News Clippings – General – High Germination Important in Seed

1967

22

7

News Clippings – General – Hoards Clippings

1960-1961, n.d.

22

8

News Clippings – General – Iowa Weed Law

1953

22

9

News Clippings – General – Lawn Weed Control

1946

22

10

News Clippings – General – Make Sure Seed Used Will Grow

1953

22

11

News Clippings – General – Mow Diverted Acres for Weed Control

1962

22

12

News Clippings – General – New Chemicals Control Weeds

1961

22

13

News Clippings – General – E.P. Sylwester

1949-1962

22

14

News Clippings – General – Vote

1930

22

15

News Clippings – General – Noxious Weed Kill

1961

22

16

News Clippings – General – Open Season Brush Work

1954

22

17

News Clippings – General – Pasture Weed Control

1954

22

18

News Clippings – General – Pest Control

1967

22

19

News Clippings – General – Plant Diseases

1967

22

20

News Clippings – General – Ragweed Control

1962

22

21

News Clippings – General – Seed Conference

1953

23

1

News Clippings – General – Seed Test

1949

23

2

News Clippings – General – Seed Test and Treatment

1950

23

3

News Clippings – General – Seed Test and Treatment

1953

23

4

News Clippings – General – Should Kill Weeds While Still Young

1954

23

5

News Clippings – General – Spray Tank

1962

23

6

News Clippings – General – Stump Sprouting

1961

23

7

News Clippings – General – TCA Good Killer of Quack Grass

1950

23

8

News Clippings – General – Use Pre-Emergence Spray to Kill Weeds

1961

23

9

News Clippings – General – Weed Control

1946

23

10

News Clippings – General – Weed Control

1960

23

11

News Clippings – General – Weed Control

1962

23

12

News Clippings – General – Weed Control – Canada Thistle

1953

23

13

News Clippings – General – Weed Control – Canada Thistle

1954

23

14

News Clippings – General – Weed Control – Dandelions

1950

23

15

News Clippings – General – Weed Control – Poison Ivy

1946

23

16

News Clippings – General – Weed Control Can Start Right Now

1954

23

17

News Clippings – General – Weed Control in Driveway

1961

23

18

News Clippings – General – Weed Control with Fertilizer

1962

23

19

Miscellaneous

1962

24

 

Printing Blocks

 

25

 

Correspondence: answers to plant queries in capacity of extension specialist

1953-1974

26

1

5 colored Kodak sheet film

n.d.

ISU Film

Collection

Symposium on Weed Control, 16mm Sound Print, Color Positive, Roy Nolan Productions – Moved to AAFF # 6-2364

n.d.

26

3

Sound Recording Tape – WOI Recording Service ISC, Ames, Iowa, program E.P. Sylwester, speed 7.5, length 3.55

n.d.

26

4

National Agricultural Chemicals Association

 

To: Radio Farm Directors and Program Directors Receiving 1956 NACA Recordings on the Use of Herbicides

 

Scripts and suggested introductions attached to this sheet correspond to the recorded features on the enclosed platters. Each platter contains four open-end features on the use of Herbicides.

 

Scripts and suggested introductions attached are:

 

26

4

Platter #201

 

1. "Herbicides Help Cotton Fight Back" (3:43) – By Claude L. Welche, Director of Production and Marketing, The National Cotton Council.

 

2. "It's the Timing That Pays" (2:40) – By Dr. Wayne C. Hall, Plant Physiologist, Texas A&M College.

 

3. "Better Grasslands with Herbicides" (3:25) - By Dr. Marion W. Parker, Head of the Weed Investigations Section, Agricultural Research Service, U.S. Department of Agriculture.

 

4. "Brushlands to Grasslands" (3:02) – Jack Dreeseen, Herbicide Specialist, National Agricultural Chemicals Assn.

 

26

4

Platter #202

 

1. "Herbicides for Highway Use" (3:13) – By Lea S. Hitchner, Executive Secretary, National Agricultural Chemicals Assn.

 

2. "Chemical Weeding of Vegetables" (3:12) – By Dr. L.L. Danielson, Plant Physiology

 

3. "Herbicides Boost Corn and Small Grain Yields" (3:57) – By Dr. E.P. Sylwester, Extension Botanist, Iowa State College.

 

4. "Chemical Frost" (3:28) – By Luther G. Jones, Specialist in Agronomy, University of California.