Disease in Plants

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Ward Harry Marshall. Disease in Plants

PREFACE

PART I. SOME FACTORS

CHAPTER I. THE PLANT AND ITS SURROUNDINGS

Notes to Chapter I

CHAPTER II. THE PLANT AND ITS FOOD

Notes to Chapter II

CHAPTER III. THE PLANT A LIVING MACHINE

Notes to Chapter III

CHAPTER IV. METABOLISM

Notes to Chapter IV

CHAPTER V. ROOTS AND ROOT-HAIRS

Notes on Chapter V

CHAPTER VI. THE FUNCTIONS OF ROOT-HAIRS

Notes on Chapter VI

CHAPTER VII. THE BIOLOGY OF SOIL

Notes to Chapter VII

CHAPTER VIII. HYBRIDISATION AND SELECTION

Notes To Chapter VIII

PART II. DISEASE IN PLANTS

CHAPTER IX. PHYTOPATHOLOGY. DERIVATION AND MEANING

Notes to Chapter IX

CHAPTER X. HEALTH AND DISEASE

Notes to Chapter X

CHAPTER XI. CAUSES OF DISEASE

Notes to Chapter XI

CHAPTER XII. CAUSES OF DISEASE. THE LIVING ENVIRONMENT

Notes to Chapter XII

CHAPTER XIII. NATURE OF DISEASE

Notes to Chapter XIII

CHAPTER XIV. NATURE OF DISEASE (Continued)

Notes to Chapter XIV

CHAPTER XV. SPREADING OF DISEASE AND EPIDEMICS

Notes to Chapter XV

CHAPTER XVI. THE FACTORS OF AN EPIDEMIC

Notes to Chapter XVI

CHAPTER XVII. REMEDIAL MEASURES

Notes to Chapter XVII

CHAPTER XVIII. VARIATION AND DISEASE

Notes to Chapter XVIII

CHAPTER XIX. SYMPTOMS OF DISEASE

Notes to Chapter XIX

CHAPTER XX. SYMPTOMS OF DISEASE (Continued)

Notes to Chapter XX

CHAPTER XXI. ARTIFICIAL WOUNDS

Notes to Chapter XXI

CHAPTER XXII. NATURAL WOUNDS

Notes to Chapter XXII

CHAPTER XXIII. EXCRESCENCES

Notes to Chapter XXIII

CHAPTER XXIV. EXCRESCENCES (continued)

Notes to Chapter XXIV

CHAPTER XXV. EXUDATIONS AND ROTTING

Notes to Chapter XXV

CHAPTER XXVI. NECROTIC DISEASES

Notes to Chapter XXVI

CHAPTER XXVII. MONSTROSITIES AND MALFORMATIONS

Notes to Chapter XXVII

CHAPTER XXVIII. PROLIFERATIONS

Notes to Chapter XXVIII

CHAPTER XXIX. GRAFTS

Notes to Chapter XXIX

CHAPTER XXX. LIFE AND DEATH

Notes to Chapter XXX

Отрывок из книги

If I were asked to sum up the most important result of the numerous advances made during the past decade in agriculture and forestry, I should reply—the clearer and wider recognition of the fact that the plant itself is the centre of the subject, and not the soil, climate, season, or other factors of its environment. Until comparatively recent times it was the habit of farmers, foresters, planters, and gardeners, all the world over, to look upon the plant as a mere item or as a mysterious if important one in their calculations, and to regard the soil as the chief factor in their studies.

Now all is changing, and the world is gradually awakening more and more to the recognition of the truth that the soil and the clouds and the atmosphere are merely reservoirs of more or less inert materials, from which the living plant draws its supplies, and works them up, by means of energy focussed from the sun, into new plant substance.

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But this does not give us any definite idea of the length of the cylinders of soil explored by these surfaces, until we find that plants such as an ordinary sunflower, hemp, or vegetable-marrow may have roots penetrating into a cubic meter of soil, in all directions, and so closely that probably no volume so large as a cubic centimeter is left unexplored. Clark found by actual measurement that the roots of a large gourd, if put end to end, extended over 25 kilometers, and Nobbe gives 520 meters for the roots of a wheat. Vetches may go nine feet deep, and oats more than three feet. The Sal, a tree of the forests of India, has roots which penetrate to a depth of 50 to 60 feet.

Some rough notion of the lengths, superficies and penetrating capacities of the roots of a large tree may be gathered from the above, but it is doubtful whether we can form any adequate ideas as to the millions of root-hairs which must be developed along the course of these subterranean boring organs.

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