Introduction
So widely spread and, it may be added, often so intelligent is the interest now taken in the incidence and the dissemination of the diseases which affect cultivated plants, and at the same time so important is a proper conception of the causations and the treatment of these diseases, that a work which deals with them cannot fail to be welcomed. Much has been and much is daily being done to advance our knowledge of plant-diseases and to increase our ability to cope with the practical difficulties that their presence creates. But the literature of the subject is so widely scattered, and the results of individual investigations so often tend, when settling some immediate difficulty, to create new difficulties, to open up new lines of research, and to indicate new principles of treatment, that in the absence of a compact, general review of the actual state of affairs, the practical man is apt to feel at a loss as to how matters really stand, and at times is disposed to doubt the soundness of the advice he is urged to follow.
The conditions necessary for the preparation of such a work as is called for are in the first place an intimate knowledge of the labours of a host of investigators widely scattered throughout the world, with at the same time ready access to the literature in which these results are embodied. But, in addition to this, the work must be something very much more than a mere compilation of the statements of others; it must be the outcome of long-continued, personal investigation of the morphological and biological peculiarities of many types of the organisms that cause or are associated with cases of disease in plants, by a writer who is not only capable of
VI representing accurately the views of others, but is competent to give reasons for the faith which he himself professes.
Mr. Massee has already shown, and nowhere more notably than in A Text-book of Plant Diseases , published by him in 1899, second edition 1903, how fully he is endowed with the qualifications required in the author of a work like the present. Various passages in that Text-book, useful and trustworthy as it has proved as a guide to the results obtained up to the date of its publication, already, however, serve rather as records of what was then believed than of what is now actually known. A further issue of what has so soon become, in some respects, a historical landmark rather than a conspectus of existing information, being undesirable, Mr. Massee has found it preferable to prepare a new work on somewhat different lines and covering a rather wider field. This work, it is hoped, may take the place of the Text-book, the issue of which has become exhausted, and should prove as helpful to those who stand in so much need of assistance as its predecessor has done.
D. PRAIN.
Royal Botanic Gardens,
Kew, 25 th January 1910.
Preface
Diseases of plants are numerous and undoubtedly do much injury. This, however, is not so much due to a lack of known, reliable, preventive or curative methods, as to a lack of application on the part of those who should be most interested in the matter. If the various well proved remedial measures now known, which are neither exorbitantly expensive nor difficult of application, were honestly carried out, the loss from fungus und animal pests would be very materially reduced.
The most important of remediable and preventive measures combined is cleanliness. Unless this fact is constantly kept in view, and practised, no amount of spraying or other modern method of dealing with disease will produce the desired result. Just now spraying is the order of the day, and under certain conditions is productive of much good ; at the same time spraying alone may be overdone, whereas when used in combination with other measures the success is greater and the cost less. Hundreds of people know, to their cost, that repeated sprayings do not always prevent Apple scab. Why? Because they do not remove the dead twigs on which the fungus winters. It is sometimes argued that this is impracticable, which is simply nonsense. The same is true of most of our diseases ; the cultivator is led to believe by the manufacturer of spraying apparatus of various preparations warranted to cure everything, and frequently supported by expert opinion, that his salvation depends on spraying alone. Notwithstanding such persuasion and advice, the cultivator will find it to his advantage to remove the primary cause of disease whenever practicable, rather than allow it to remain, and
vii vm endeavour, by means of spraying alone, to keep it under subjection. Diseased branches, fruit, etc., should be removed — in fact, as far as practicable, all diseased material should be destroyed. Unfortunately it is not always possible to do so, as when potatoes attacked by Black scab, or turnips suffering from Finger-and-toe rot in the ground. In such cases the land should be sterilised by the use of quicklime or gas-lime.
Much has been written of late respecting the great advantage derived from certain fungi parasitic on insects. Such statements are perfectly true ; myriads of destructive insects are destroyed by such means. This has happened in the past, and will continue in the future. The one thing to refrain from is that of investing money in any scheme having for its object the extermination of injurious insects through the agency of fungi. Any such investment will be regretted.
The numerous references given in this book indicate my great indebtedness to other investigators, to whom I respectively tender my best thanks. Finally, to my colleague, Mr. A. D. Cotton, I am indebted for calling attention to many subjects which would otherwise have been omitted.
GEO. MASSEE.
Gateacre, Kew Gardens,
The opening of the book is shown; the full text loads in the reader.
Loading the full text…
The end
You’ve reached the end of Diseases of cultivated plants and trees.