Johann C. Fabricius' keen observations of science and economics make this book an essential contribution to the early development of phytopathology.

The Attempt at a Dissertation on the Diseases of Plants by Johann Christian Fabricius is an essential contribution to the early development of Phytopathology. By the elaborate system, natural to the pupil of Linne, by the copious material collected, but mostly by the critical remarks, the Attempt far exceeds its sources and contemporary writings. The combined interest of science and economics, an essential requirement for phytopathologists, a great gift of observation, and a keen power of criticism are revealed in the pages of the Attempt. However, the ideas taken up here were crowded out by his pursuit of evolution and in particular by entomology. He attempts a new method and deduces the classes and genera according to the apparent cases, but the species according to the causes of the disease.

Attempt at a Dissertation on the Diseases of Plants

Class I.

Rendering unproductive are those cases in which the plants are prevented from setting fruit or are rendered distinctly less fruitful. This is frequently not observed until after blossoming

Class II.

Wasting are those cases in which the plants are slowly killed, their growth and strength gradually decreasing

Class III.

Decaying are those cases in which the main parts of the plants are decomposed and become a rotting mass, which by degrees is transformed to mouldy soil

Class IV.

Discharging are those cases showing an abnormal flow

Class V.

Rendering misshapen, recognized by the abnormal development of the external parts

Class VI.

Extraneous are those cases due to the apparent injury to the parts