Plant Disease (Collins New Naturalist Library, Volume 85)
David Ingram, Noel Robertson
Language: English
Pages: 334
ISBN: B00BS06TM4
Format: PDF / Kindle (mobi) / ePub
Plant Disease covers all aspects of diseases of plants growing in the wild or likely to be encountered on cultivated plants in farm, forest and garden. This edition is exclusive to newnaturalists.com This book covers all aspects of diseases of plants growing in the wild or likely to be encountered on cultivated plants in farm, forest and garden. Between 1845 and 1851 one and a half million Irish men, women and children died in misery from starvation and disease; the result of potato blight, a fungal disease that destroyed their potato crops. A million more people, driven to despair by the succession of appalling harvests, emigrated, mostly to America. So it was that a plant disease changed the course of history, its economic effects causing not only social but also major political upheaval. Many plant diseases have had surprisingly far reaching social and economic effects, so the study of these diseases is of great interest and importance to scientists, horticulturists, agriculturalists and foresters. In Plant Disease: A Natural History, Ingram and Robertson draw on personal observations in the field and laboratory to discuss all types of diseases caused by fungi, from rots and mildews to rusts, smuts and tumours. The symptoms encountered in the wild are described, together with their causes. A final chapter discusses the diseases caused by viruses, bacteria and flowering plants.
from Switzerland. Working in France in 1807, Prévost not only confirmed Tillet’s findings but also germinated bunt ustilospores in the laboratory and guessed that they infected the young plant. The nature of this ustilospore germination was beautifully illustrated by the brothers Tulasne in 1847. A germ tube (the promycelium) is first produced, bearing at the tip uninucleate needle-shaped structures, the primary sporidia (Fig. 10.4). These fuse and produce secondary binucleate sporidia which then
of bacterial diseases is given by Bradbury (2000) and Lelliot and Stead (1987), and for virus diseases by Hill (1984), Walkey (1990) and Matthews (1991, 1992). EXAMINATION WITH A MICROSCOPE More detailed examination may be carried out by using a stereoscopic (low power: x20 – x200) dissecting microscope or a compound (high power: x100 – x1000+) microscope. The naturalist can do quite a lot without a microscope, but there is no doubt that possession of such a piece of equipment adds greatly to
tissues, especially certain glycoproteins and the dark products of oxidised phenols formed when cells are killed. The presence of inhibitors may explain why some fungi cause firm rots and others soft rots, a difference which is very obvious in apples infected by either Monilinia fructigena or another necrotroph causing rots in apples, Penicillium expansum (Fig. 2.3). Both are capable of producing a wide range of pectic enzymes, yet M. fructigena causes a dark, firm rot in apple fruits while P.
in advance of infection, thus negating active defence processes. These are called pathotoxins. This is analogous to the situation in certain diseases of humans: as long ago as the nineteenth century, Louis Pasteur showed that the symptoms of tetanus and diphtheria are caused largely by toxins produced by the bacterial pathogens responsible for these diseases. Toxins produced by necrotrophic plant pathogens may kill cells so rapidly that areas of dead tissue develop on leaves, stems or roots; or
years in Egypt and the Middle East which, with their consequences for Joseph and Moses, so profoundly influenced the history of the Jewish people, were the result of a rust epidemic. Various references in Greek and Roman writers are also taken to refer to the rusts, but it is not always easy from the written accounts to separate the effects from those of powdery mildews (see Chapter 8), smuts and bunts (see Chapter 10) and unfavourable droughts or drying winds. The Romans were sufficiently