Late-Blight Tuber Rot of the Potato by George K. K. Link and F. C. Meier examines a disease that can damage a crop in the ground and continue causing losses after harvest. The United States Department of Agriculture issued this short work as Department Circular No. 220, dated May 1922.
The authors are identified as pathologists. Their explanation is organized as a series of practical questions, moving from recognition of damaged tubers to the conditions under which infection develops and the relationship between field management, transport and storage.
Recognizing damage in the tuber
The opening sections distinguish visible changes in a potato from the organism responsible for them. Brownish or purplish areas, changes beneath the skin and the texture of damaged tissue are described.
A photographic plate shows affected tubers in section together with foliage injury. The pictures make the connection between disease on the growing plant and deterioration of the underground crop more concrete.
The account also discusses secondary decay. It explains how an initial lesion may provide an opening for other organisms, so that a potato originally affected by one disease can later present a more complicated form of rotting.
From foliage to the harvested crop
Separate questions consider effects on the tops, the places and seasons in which the disease occurs and how it gets started in a field. The circular follows infection from diseased planting stock and affected foliage to nearby plants and tubers.
This sequence is the main practical strength of the document. Field symptoms and storage trouble are treated as parts of one problem, rather than as unrelated losses at different stages of production.
The authors use the scientific name Phytophthora infestans and the terminology of their period. Their description of its classification and biology belongs to the historical publication.
Moisture, temperature and delayed symptoms
The discussion of favorable conditions gives particular attention to moisture and temperature. It distinguishes the presence of contamination from the establishment of infection and the later appearance of visible damage.
That distinction matters when interpreting a harvested lot. The circular explains why potatoes that appear sound when loaded or stored may develop symptoms later.
Reported storage observations compare outcomes at different temperatures. These figures document the authors’ investigation; they should be read in their experimental setting rather than as universal predictions for every store or crop.
A further section asks whether the disease spreads after harvesting. It considers the conditions in which an affected tuber can become a source of infection for others nearby.
Field work and storage decisions
The closing discussion brings together planting stock, spraying, the timing of digging, weather, handling and storage conditions. A second plate compares fields in an account of blight control.
The recommendations show how early extension writing tried to connect actions before harvest with losses afterward. They also illustrate the difficulty of choosing a digging date when a diseased crop meets changing weather.
The circular contains period chemical and food-use advice. Those passages are historical material, not current recommendations for treating a crop or deciding whether damaged potatoes are safe to eat.
Audience and digital copy
This free ebook suits readers studying potato diseases, crop storage and the development of agricultural advice. Its question-and-answer structure makes it easy to follow a particular issue without reading a long general manual.
The PDF contains 11 digital pages, including blank leaves, a title page, five numbered text pages and two photographic plates. The issue is dated May 1922; the printing-office line carries 1921. Both details are retained in the scan. Small captions and discolored paper benefit from enlargement.
Book details
- Author: George K. K. Link and F. C. Meier
- Publisher: United States Department of Agriculture; Government Printing Office, Washington
- Year: 1922
- Edition: Department Circular No. 220; May 1922 issue
- Digital length: 11 PDF pages
- Language: English
- File size: 0.88 MB
