Control of Blackleg Disease of the Potato by W. J. Morse reports investigations by the Maine Agricultural Experiment Station. Published in November 1911 as Bulletin No. 194, it combines a description of the disease with laboratory observations and cooperative field experiments.
The main text uses the fuller heading Control of the Blackleg or Black-Stem Disease of the Potato. Its emphasis is the condition of planting stock and the practical problem of reducing infection in potatoes grown for the seed trade.
Recognizing the problem
Morse begins by explaining the disease names and the uncertainty surrounding the organisms associated with similar symptoms. He limits parts of his discussion explicitly to observations made in Maine.
The account describes blackening near the base of an affected stem, decay in the original seed piece and the relationship between infected stems and soft rot in tubers. An early photograph shows diseased potato plants.
The discussion also distinguishes blackleg from other causes of rotting. Morse considers severe storage losses that followed late blight and explains why he did not attribute every soft decay to the blackleg organism.
This care over distinctions is a useful feature of the bulletin. A visible symptom is treated as something to investigate, rather than as sufficient proof that every damaged crop has the same cause.
Why the seed trade mattered
The regional setting is important. Maine potatoes were being sold for planting farther south, where the author reports different levels of damage and demand for early varieties.
Irish Cobbler receives particular attention in comparison with varieties commonly grown for table use. The commercial value of northern-grown planting stock made disease reduction a matter of concern beyond an individual field.
For agricultural historians, this section connects plant pathology with trade. The standards expected of seed potatoes affected both the reputation of a producing district and the methods growers were asked to adopt.
From cultures to cooperative trials
The preliminary experimental work considers the organisms’ response to drying, sunlight and disinfectants. Morse then follows possible routes by which infection could reach a healthy seed piece.
The field experiments were carried out with cooperating growers. The methods section explains the selection of stock, division of fields and comparison of treated and untreated portions.
Individual reports describe the conditions encountered at different farms. These details include varieties, the treatment used, the condition of the crop and counts of diseased plants.
The result is more informative than a list of remedies. The reader can see how an early experiment-station worker tried to test a proposed control method under ordinary farm conditions.
Interpreting the results
A tabular summary brings the cooperative trials together. The discussion considers the apparent effectiveness of treatment and the possible influence of seed selection and handling.
Separate sections examine carryover in soil under Maine conditions, infection of healthy cut pieces and the effect of treatment on the vigor of resulting plants.
The author does not describe all experimental circumstances as identical. Differences in stock and the amount of disease in untreated checks help explain why individual comparisons need careful reading.
Readers interested in research methods will find these qualifications useful. They show the relationship between an observed result, the conditions of a trial and the strength of the conclusion that can reasonably be drawn.
Historical control methods
The concluding section sets out the methods Morse favored for eliminating blackleg from seed potatoes. It includes an illustrated description in words of the equipment and arrangements used for treating stock.
Formaldehyde treatments occupy a substantial part of the bulletin. These are historical experimental procedures, not current instructions for handling seed or treating a food crop. Modern diagnosis and control require current agricultural guidance.
The value of retaining this material is documentary: it records the questions, tools and reasoning used at an important stage in the development of potato disease management.
Audience and digital copy
This free ebook is suited to readers studying potato history, seed production and early cooperative agricultural research. Its strongest features are the detailed field reports and the explicit connection between planting material and disease.
The PDF contains 34 digital pages, including the original front matter, a photograph and the text paginated 201–228. The scan has yellowed paper and occasional show-through. Enlarge the tables and footnotes when comparing experimental results.
Book details
- Author: W. J. Morse
- Publisher: Maine Agricultural Experiment Station, Orono, Maine
- Year: 1911
- Edition: Bulletin No. 194; November 1911
- Digital length: 34 PDF pages
- Language: English
- File size: 1.40 MB
