Dennis Robert Hoagland

Dennis Robert Hoagland (April 2, 1884 – September 5, 1949) was a chemist and plant scientist working in the fields of plant nutrition, agricultural chemistry, and physiology. He was Professor of Plant Nutrition at the University of California at Berkeley from 1927 until his death in 1949. He is commonly known especially for his pioneering work on hydroponics and the development of the Hoagland solution.[1] The Dennis R. Hoagland Award, first presented by the American Society of Plant Biologists in 1985, is named in his honor.[2]

This article is about the plant scientist. For the man who disappeared in Connecticut in 2013, see Disappearance of Robert Hoagland.
Dennis Robert Hoagland
BornApril 2, 1884
Golden, Colorado, USA
DiedSeptember 5, 1949 (1949-09-06) (aged 65)
Oakland, California
CitizenshipAmerican
Alma materStanford University
University of Wisconsin, Madison
Known forHoagland solution
AwardsNewcomb Cleveland Prize Stephen Hales Prize
Scientific career
FieldsPlant Scientist, Chemist
InstitutionsUniversity of California, Berkeley

Biography

Early life and career

Hoagland graduated from Stanford University (1907) with a major in chemistry. In 1908 he became an instructor and assistant in the Laboratory of Animal Nutrition at the University of California at Berkeley, an institution with which he would be associated for the remainder of his life. He worked in the fields of animal nutrition and biochemistry until 1912, when he entered the graduate school in the department of agricultural chemistry (McCollum lab) at the University of Wisconsin, receiving his master's degree in 1913. The following year he became Assistant Professor of agricultural chemistry and in 1922 Associate Professor of plant nutrition at Berkeley.[3]

Private life

In 1920, Dennis R. Hoagland married Jessie A. Smiley. She died suddenly of pneumonia in 1933. He was left with the responsibility of bringing up three young boys.[4]

Work

During the World War I, Hoagland tried to substitute the lack of imports of potassium-based fertilizers from the German Empire to the United States with plant extracts from brown algae. He investigated the ability of plants to absorb salts against a concentration gradient and discovered the dependence of nutrient absorption and translocation on metabolic energy using innovative model systems. During his systematic research he developed the basic formula for the Hoagland solution based on the composition of soil solutions obtained from high productivity soils, and established the essentiality of molybdenum for the growth of tomato plants. Hoagland was able to show that various plant diseases are caused by a lack of trace elements such as zinc. Further work dealt with plant-soil interactions implying the physiology of soil solutions and the pH dependence of plant growth, thus, contributing to the understanding of fundamental cellular physiological processes in green plants.[5]

A Hoagland hydroponic and soil culture solution provides every essential nutrient required by green plants being appropriate for the growth of a large variety of plant species.[6] The solution described by Hoagland and Snyder (1933)[7] has been modified several times, for example, by Hoagland and Arnon (1938, 1950), notably with the number and concentrations of micronutrients[8] and the addition of iron chelates.[9]

Hoagland's research was influenced by the plant pathologists H. E. Thomas and W. C. Snyder, and another pioneer of plant nutrition and hydroponics, William Frederick Gericke.[10] Gericke's positive results in this field inspired him to expand their research on hydroponics finally resulting in the Hoagland solutions (1) and (2).[11] The composition of macronutrients of the Hoagland solution (1) can be traced back to Wilhelm Knop's four-salt mixture[12] and the respective salt and element concentrations to Dennis Hoagland.[13] Knop's solution in contrast to Hoagland's solution was not supplemented with trace elements (micronutrients) because the chemicals were not particularly pure in Wilhelm Knop's day. More highly purified chemicals and more sensitive methods for analysing trace concentrations were developed from 1930 and onwards.[14]

Hoagland's students included Daniel Israel Arnon who developed the Hoagland solution (2) as a result of joint efforts,[15] and Folke Karl Skoog.[16] Unlike the Murashige and Skoog medium, the Hoagland solution contains neither vitamins nor other organic compounds, but essential minerals for plant nutrition. It is concluded that the promotion of growth of tobacco callus cultured on White's modified medium is due mainly to inorganic rather than organic constituents in aqueous tobacco leaf extracts added.[17]

Awards and honors

Hoagland became a Fellow of the American Association for the Advancement of Science (AAAS) in 1916 and member of the National Academy of Sciences in 1934.[18] In recognition of his many discoveries, the American Society of Plant Physiologists elected Dennis Hoagland as president in 1932 and awarded him the first Stephen Hales Prize in 1929.[19] In 1940, together with Daniel I. Arnon, he received the AAAS Newcomb Cleveland Prize for the work "Availability of Nutrients with Special Reference to Physiological Aspects".[20] In 1944 he published his Lectures on the Inorganic Nutrition of Plants subtitled "Prather Lectures at Harvard University" which he was invited in 1942 to give at Harvard University. In 1945 he was elected member of the American Academy of Arts and Sciences.[21]

Perception

Nowadays the most common solutions for plant nutrition and plant tissue cultivation are the formulations from Hoagland and Arnon (1938, 1950),[22] and Murashige and Skoog (1962).[23] Their basic formulas are being replicated by modern manufacturers to commercially produce liquid concentrated fertilizers for plant breeders, average consumers, and the life sciences. Even their names are partly used as a brand for innovative products, e.g., basal salt mixtures.[24][25]

Hoagland's great research merit was to develop the Hoagland solution, thereby, creating the basis for a modern balanced plant nutrition that is still valid today. His fundamental research contributions are of historical relevance being reflected in the following bibliography. Though some sources claim the opposite, Gericke's and Hoagland's recipes for plant nutrition were developed independently of one another. Even if Hoagland and Arnon were never awarded the Nobel Prize for their outstanding research work on plant physiology and nutrition, the Hoagland solution, although never been applied for a patent, is still one of the most important inventions of modern times.[26]

Bibliography
1912

The Determination of Aluminum in Feces. With C. L. A. Schmidt. J. Biol. Chem., 11(4) :387-391.

1913

Studies of the Endogenous Metabolism of the Pig as Modified by Various Factors. (I.-III.). With E. V. McCollum. J. Biol. Chem., 16(3) :299-325.

1915

The Destructive Distillation of Pacific Coast Kelps. J. Ind. Eng. Chem., 7(8) :673-676.

Organic Constituents of Pacific Coast Kelps. J. Agr. Res., 4(1) :39-58.

The Complex Carbohydrates and Forms of Sulphur in Marine Algae of the Pacific Coast. With L. L. Lieb. J. Biol. Chem., 23(1) :287-297.

1916

Acidity and Adsorption in Soils as Measured by the Hydrogen Electrode. With L. T. Sharp. J. Agr. Res., 7 :123-145.

1917

The Effect of Hydrogen and Hydroxyl Ion Concentration on the Growth of Barley Seedlings. Soil Sci., 3(6) :547-560.

1918

Relation of Carbon Dioxide to Soil Reaction as Measured by the Hydrogen Electrode. With L. T. Sharp. J. Agr. Res., 12(3) :139-148.

The Freezing-Point Method as an Index of Variations in the Soil Solution Due to Season and Crop Growth. J. Agr. Res., 12(6) :369-395.

The Chemical Effects of CaO and CaCO3 on the Soil. Part I. The Effect on Soil Reaction. With A. W. Christie. Soil Sci., 5(5) :379-382.

The Relation of the Plant to the Reaction of the Nutrient Solution. Science, 48(1243) :422-425.

1919

Notes on Recent Work Concerning Acid Soils. With L. T. Sharp. Soil Sci. 7(3) :197-200.

Note on the Technique of Solution Culture Experiments with Plants. Science, 49(1267) :360-362.

The Effect of Certain Aluminum Compounds on the Metabolism of Man. With C. L. A. Schmidt. Univ. Calif. Pub. Path., 2(20) :215-244.

Table of pH, H+ , and OH− Values; Corresponding to Electromotive Forces Determined in Hydrogen Electrode Measurements, with a Bibliography. With C. L. A. Schmidt. Univ. Calif. Pub. Phys., 5(4): 23-69.

Relation of Nutrient Solution to Composition and Reaction of Cell Sap of Barley. Bot. Gaz., 68(4) :297-304.

Relation of the Concentration and Reaction of the Nutrient Medium to the Growth and Absorption of the Plant. J. Agr. Res., 18(2) :73-117.

The Effect of Several Types of Irrigation Water on the pH Value and Freezing Point Depression of Various Types of Soils. With A. W. Christie. Univ. Calif. Pub. Agr. Sci., 4(6) :141-158.

1920

Optimum Nutrient Solutions for Plants. Science, 52(1354) :562-564.

Effect of Season and Crop Growth on the Physical State of the Soil. With J. C. Martin. J. Agr. Res., 20(5) :396-4O3.

Relation of the Soil Solution to the Soil Extract. With J. C. Martin and G. R. Stewart. J. Agr. Res., 20(5) :381-395.

1922

The Soil Solution in Relation to the Plant. Trans. Far. Soc., 17(2) :249-254.

Soil Analysis and Soil and Plant Interrelations. Calif. Agr. Exp. Sta. Cir., 235 :1-7.

Soil Analysis and Soil and Plant Interrelations. Citrus Leaves, 2(6) :1-2, 16-17.

1923

The Feeding Power of Plants. With A. R. Davis and C. B. Lipman. Science, 57(1471) :299-301.

The Composition of the Cell Sap of the Plant in Relation to the Absorption of Ions. With A. R. Davis. J. Gen. Phys., 5(5) :629-646.

Effect of Salt on the Intake of Inorganic Elements and on the Buffer System of the Plant. With J. C. Martin. Calif. Agr. Exp. Sta. Tech. P., 8 :1-26.

Further Experiments on the Absorption of Ions by Plants, Including Observations on the Effect of Light. With A. R. Davis. J. Gen. Phys., 6(1) :47-62.

The Absorption of Ions by Plants. Soil Sci., 16(4) :225-246.

A Comparison of Sand and Solution Cultures with Soils as Media for Plant Growth. With J. C. Martin. Soil Sci., 16(5) :367-388.

The Effect of the Plant on the Reaction of the Culture Solution. Calif. Agr. Exp. Sta. Tech. P., 12 :1-16.

1924

The Electrical Charge on a Clay Colloid as Influenced by Hydrogen-Ion Concentration and by Different Salts. With W. C. Dayhuff. Soil Sci., 18(5) :401-408.

1925

Suggestions Concerning the Absorption of Ions by Plants. With A. R. Davis. The New Phytologist, 24(2) :99-111.

Physiological Aspects of Soil Solution Investigations. Calif. Agr. Exp. Sta. Hilg., 1(11) :227-257.

1926

Some Phases of the Inorganic Nutrition of Plants in Relation to the Soil Solution: 1. The Growth of Plants in Artificial Culture Media. Sci. Agr., 6(5) :141-151.

Some Phases of the Inorganic Nutrition of Plants in Relation to the Soil Solution: 2. Soil Solutions as Media for Plant Growth. Sci. Agr., 6(6) :177-189.

Effect of Certain Alkali Salts on Growth of Plants. With J. S. Burd and A. R. Davis. (20) Abstract. Nature and Promise of Soil Solution. (21) Abstract of Papers Read Before Pan-Pacific Scientific Congress, Australia.

The Influence of Light, Temperature and Other Conditions on the Ability of Nitella Cells to Concentrate Halogens in the Cell Sap. With P. L. Hibbard and A. R. Davis. J. Gen. Phys., 10(1) :121-146.

The Investigation of the Soil from the Point of View of the Physiology of the Plant. 4th Int. Conf. Soil Sci. Rome, 1924, 3 :535-544.

1927

The Synthesis of Vitamin E by Plants Grown in Culture Solutions. With H. M. Evans. Am. J. Phys., 80(3) :702-704.

Recent Experiments Concerning the Adequacy of Artificial Culture Solutions and of Soil Solutions for the Growth of Different Types of Plants. With J. C. Martin. Proceedings and Papers of the First Int. Cong. Soil Sci., 3 :1-12.

Resume of Recent Soil Investigations at the University of California. Mo. Bull. Calif. Dept. Agr., 16(11) :562-568.

1928

First International Congress of Soil Science, Fourth Commission, Soil Fertility. (Summary.) Soil Sci., 25(1) :45-50.

The Influence of One Ion on the Accumulation of Another by Plant Cells with Special Reference to Experiments with Nitella. With A. R. Davis and P. L. Hibbard. Plant Phys., 3(4) :473-486.

An Apparatus for the Growth of Plants in Controlled Environment. With A. R. Davis. Plant Phys., 3(3) :277-292.

1929

Minimum Potassium Level Required by Tomato Plants Grown in Water Cultures. With E. S. Johnston. Soil Sci., 27(2) :89-109.

The Intake and Accumulation of Electrolytes by Plant Cells. With A. R. Davis. Protoplasma, 6(4) :610-626.

1930

Fertilizer Problems and Analysis of Soils in California. Calif. Agr. Exp. Sta. Cir., 317 :1-16.

Accumulation of Mineral Elements by Plant Cells. Contrib. Marine Biol., pp.  131–144.

Recent Advances in Plant Physiology. Ecology, 11(4) :785-786.

1931

Little-Leaf or Rosette in Fruit Trees, I. With W. H. Chandler and P. L. Hibbard. Proc. Am. Soc. Hort. Sci., 28 :556-560.

Absorption of Mineral Elements by Plants in Relation to Soil Problems. Plant Phys., 6(3) :373-388.

1932

Little-Leaf or Rosette of Fruit Trees, II: Effect of Zinc and Other Treatments. With W. H. Chandler and P. L. Hibbard. Proc. Am. Soc. Hort. Sci., 29 :255-263.

Mineral Nutrition of Plants. Annu. Rev. Biochem., 1 :618-636.

Some Effects of Deficiencies of Phosphate and Potassium on the Growth and Composition of Fruit Trees under Controlled Conditions. With W. H. Chandler. Proc. Am. Soc. Hort. Sci., 29 :267-271.

1933

Little-Leaf or Rosette of Fruit Trees, III. With W. H. Chandler and P. L. Hibbard. Proc. Am. Soc. Hort. Sci., 30 :70-86.

Mineral Nutrition of Plants. Annu. Rev. Biochem., 2 :471-484.

Nutrition of Strawberry Plant under Controlled Conditions. (a) Effects of Deficiencies of Boron and Certain Other Elements, (b) Susceptibility to Injury from Sodium Salts. With W.C. Snyder. Proc. Am. Soc. Hort. Sci., 30 :288–294.

Absorption of Potassium by Plants in Relation to Replaceable, Non-Replaceable, and Soil Solution Potassium. With J. C. Martin. Soil Sci., 36 :1-33.

Methods for Determining Availability of Potassium with Special Reference to Semi-Arid Soils. Trans. 2nd Commission and Alkali Subcommission of the International Soc. Soil Sci. Kjobenhavn (Danmark). Vol. A, pp.  25–31.

1934

Little-Leaf or Rosette of Fruit Trees, IV. With W. H. Chandler and P. L. Hibbard. Proc. Am. Soc. Hort. Sci., 32 :11-19.

The Potassium Nutrition of Barley with Special Reference to California Soils. Proc. Fifth Pacific Science Congress, pp.  2669–2676.

1935

Little-Leaf or Rosette of Fruit Trees, V: Effect of Zinc on the Growth of Plants of Various Types in Controlled Soil and Water Culture Experiments. With W. H. Chandler and P. L. Hibbard. Proc. Am. Soc. Hort. Sci., 33 :131-141.

Comments on the Article by A Kozlowski on "Little Leaf or Rosette of Fruit Trees in California". With W. H. Chandler. Phytopathology, 25(5) :522-522

Absorption of Potassium by Plants and Fixation by the Soil in Relation to Certain Methods for Estimating Available Nutrients. With J. C. Martin. Trans. Third Inter. Cong. Soil Sci., 1 :99-103.

1936

Little-Leaf or Rosette of Fruit Trees, VI: Further Experiments Bearing on the Cause of the Disease. With W. H. Chandler and P. R. Stout. Proc. Am. Soc. Hort. Sci., 34 :210-212.

The Plant as a Metabolic Unit in the Soil-Plant System. Essays in Geobotany in Honor of Wm. A. Setchell. Univ. Calif. Press, pp. 219–245.

General Nature of the Process of Salt Accumulation by Roots with Description of Experimental Methods. With T. C. Broyer. Plant Phys., 11(3) :471-507.

1937

Some Aspects of the Salt Nutrition of Higher Plants. Bot. Rev., 3 :307-334.

1938

The Water-Culture Method of Growing Plants without Soil. With D. I. Arnon. Calif. Agr. Exp. Sta. Cir., 347, pp.  1-39.

1939

A Comparison of Water Culture and Soil as Media for Crop Production. With D. I. Arnon. Science, 89 :512-514.

Upward and Lateral Movement of Salt in Certain Plants as Indicated by Radioactive Isotopes of Potassium, Sodium, and Phosphorus Absorbed by Roots. With P. R. Stout. Am. J. Bot., 26(5) :320-324.

Metabolism and Salt Absorption by Plants. With F. C. Steward. Nature, 143 :1031-1032.

1940

Salt Absorption by Plants. With F. C. Steward. Nature, 145 :116-117.

Hydrogen-Ion Effects and the Accumulation of Salt by Barley Roots as Influenced by Metabolism. With T. C. Broyer. Am. J. Bot., 27 :173-185.

Upward Movement of Salt in the Plant. With T. C. Broyer and P. R. Stout. Nature, 146 :340-340.

Minute Amounts of Chemical Elements in Relation to Plant Growth. Science, 91 :557-560.

Methods of Sap Expression from Plant Tissues with Special Reference to Studies on Salt Accumulation by Excised Barley Roots. With T. C. Broyer. Am. J. Bot., 27(7) :501-511.

Crop Production in Artificial Culture Solutions and in Soils with Special Reference to Factors Influencing Yields and Absorption of Inorganic Nutrients. With D. I. Arnon. Soil Sci., 50(1) :463-485.

Salt Accumulation by Plant Cells with Special Reference to Metabolism and Experiments on Barley Roots. Cold Spring Harbor Symposia on Quantitative Biology, Vol. 8.

Some Modern Advances in the Study of Plant Nutrition. Proc. Am. Soc. Sugar Beet Tech., Part 1 :18-26.

1941

Water Culture Experiments on Molybdenum and Copper Deficiencies of Fruit Trees. Proc. Am. Soc. Hort. Sci., 38 :8-12.

Physiological Aspects of Availability of Nutrients for Plant Growth. With D. I. Arnon. Soil Sci., 51(1) :431-444.

Aspects of Progress in the Study of Plant Nutrition. Trop. Agr., 18 :247.

1942

Accumulation of Salt and Permeability in Plant Cells. With T. C. Broyer. J. Gen. Physiol., 25(6) :865-880.

1943

Metabolic Activities of Roots and Their Bearing on the Relation of Upward Movement of Salts and Water in Plants. With T. C. Broyer. Am. J. Bot., 30(4) :261-273.

Composition of the Tomato Plant as Influenced by Nutrient Supply, in Relation to Fruiting. With D. I. Arnon. Bot. Gaz., 104(4) :576-590.

1944

General Aspects of the Study of Plant Nutrition. Sci. Univ. Calif., pp. 279–294.

The Investigation of Plant Nutrition by Artificial Culture Methods. With D. I. Arnon. Biol. Rev. Cambr. Phil. Soc., 19(2) :55-67.

Lectures on the Inorganic Nutrition of Plants. (Prather Lectures at Harvard University). Published by Chronica Botanica Co. Waltham, Mass.

1945

Molybdenum in Relation to Plant Growth. Soil Sci., 60(2) :119-123.

Potassium Fixation in Soils in Replaceable and Non-Replaceable Forms in Relation to Chemical Reactions in the Soil. With J. C. Martin and R. Overstreet. Soil Sci. Soc. Am. Proc., 10 :94-101.

1946

The Nutrition and Biochemistry of Plants, Currents in Biochemical Research. Interscience Publ. Inc. N. Y., pp.  61–77.

Little-Leaf or Rosette of Fruit Trees, VIII: Zinc and Copper Deficiency in Corral Soils. With W. H. Chandler and J. C. Martin. Proc. Am. Soc. Hort. Sci., 47 :15-19.

1947

Trace Elements in Plants and Animals by Walter Stiles. Rev. Arch. Biochem., 13 :311-312.

Fertilizers, Soil Analysis and Plant Nutrition. Calif. Agr. Exp. Sta. Cir., 367.

1948

Minute Amounts of "Minor" Elements Essential in Addition to "Regular" Fertilizer. Agr. Chem.

Some Problems of Plant Nutrition. With D. I. Arnon. Sci. Mo., 67(3): 201-209.

1950

Absorption and Utilization of Inorganic Substances in Plants. With P. R. Stout. Chap. VIII of Agricultural Chemistry, ed. by Frear, Van Nostrand.

The Water-Culture Method of Growing Plants without Soil. With D. I. Arnon. Calif. Agr. Exp. Sta. Cir., 347, pp.  1-32 (Revision).

Availability of Potassium to Crops in Relation to Replaceable and Non-Replaceable Potassium and to Effects of Cropping and Organic Matter. With J. C. Martin. Soil Sci. Soc. Am. Proc., 15 :272-278.

Courtesy of The National Academy of Sciences Archives, and without these entries it would not have been possible.

References
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