The success of such breeding program relied heavily on the ability to quickly identify immune varieties. Spieckermann and Kotthoff, at the Münster Haupstelle für Pflanzenschutz, were the first ones to develop, in 1925, a simple method of inoculation to test the susceptibility of potatoes to wart disease. They cut potatoes of various varieties into pieces, placed them in a box side by side over a layer of humid sand with the eyes turned up, and covered them with Krebscompost, a compost rich in winter sporangia prepared from warted material.[33] In non-resistant varieties, the infection spread through the eyes and was soon made manifest by the formation of a gall.
BRA researchers in Berlin-Dahlem would improve this method and convert it into the standard procedure for testing varieties for wart resistance from 1930 on. Köhler and Lemmerzahl, building also on work from Mary D. Glynne at the British Rothamsted Experimental Station, replaced the winter sporangia with summer sporangia obtained from warted tissues collected from infected potatoes. By inoculating summer sporangia directly into the tuber sprouts, ideally when the sprouts were about 2 millimeters long, infections were detected already after 4 hours of inoculation. This so-called Glynne-Lemmerzahl method not only saved a considerable amount of time; it also made it possible to circumvent the use of large amounts of wart compost, which the previous method had required. It also required much less laboratory space. By 1929 the BRA had tested resistance to wart disease in about 10,000 breeding lines, a number that would climb to 30,000 in 1936 and that justified every effort to streamline inoculation procedures.[34]
Success in identifying susceptibility to wart would make resistance to that disease an exemplary case for a cleansing of the seed market. Through application of the Glynne-Lemmerzahl method on a grand scale, non-resistant varieties were to be eliminated from the German fields. As has already been mentioned, potato farmers had about 1,500 varieties at their disposal by the end of the 1910s.[35] The launching of Varietal Registering Committees (Sortenregisterkomissionen) for potatoes shortly after the war by Appel in conjunction with the German Agricultural Society (DLG), an initiative not extended to cereals until 1927, was aimed at sorting out “original varieties” from cheap imitations as a way to reduce the number of varieties and allow farmers to make better-informed decisions.[36] In the 1920s the DLG began to distribute to its members an annual booklet of approved varieties. During the Nazi regime, that booklet would evolve into an official Imperial List of Approved Varieties (Reichssortenliste).
The research on wart disease had also led to an important development in the methodology for classifying potato varieties. The close attention to tuber sprouts demanded by the Lemmerzahl-Glynne method revealed their usefulness as markers of different varieties. Soon BRA researchers developed, parallel to the inoculation method, a new biological basis for establishing equivalence or distinction between varieties on the basis of observation of the form, size, and color of tuber sprouts—the so-called sprout test (Lichtkeimprüfung).[37] Before a commercial variety could make the list of approved varieties, it had to demonstrate its distinctiveness (Selbständigkeit) in relation to existent varieties. Before BRA researchers began to publish the list of varieties, seed merchants could simply cultivate other breeders’ creations, rename them, and sell them as their own at a cheaper price. Distinctiveness was based on characteristics (Merkmalen) such as color and form of the tuber and, after K. Snell’s work by the end of the 1920s, also on certain features of the sprouts.[38] But distinctiveness was not enough to gain entry to the list. A variety developed by a commercial breeder had also to possess interesting agronomic qualities (Eigenschaften) of yield, resistance, adaptability to different soils, color of pulp, or tuber form. To be on the list, potatoes had thus to pass through the standardized tests of the BRA that established their biological characteristics and agronomic qualities. In short, BRA researchers developed quick laboratory testing methods to guide commercial breeders’ work as well as to identify the varieties that should or should not be included in the list of approved varieties.[39]
The BRA and the RNS: The Streamlined Estate and the 1934 Seed Decree
The Seed Decree issued by Darré’s Ministry in March 1934, only one year into Nazi rule, established a compulsory registering system in which only the best varieties of each crop were allowed into the list, these being the only ones that could be sold in the market. The change brought by the decree was an important one, and in 1937 there were no more than 74 potato varieties in the list.[40] As has already been noted, lists of approved varieties were being elaborated by the BRA and publicized by the DLG as guidance for farmers and peasants, but only after the seed decree of 1934 was it forbidden by law to commercialize varieties excluded from the list.[41] With the Nazis’ Battle of Production, not only were there far fewer approved varieties; those varieties were the only ones legally commercialized. In subsequent years, the exclusion of some varieties would extend to cultivation itself.
According to BRA data, in 1935 around 75 percent of the German fields were already being cultivated with approved potato varieties resistant to wart disease.[42] That is an impressive number indeed if we recall that by 1925 only 24 varieties had been identified as holding resistance to wart. In 1937 a new decree was issued strictly banning the commercialization of seeds from susceptible varieties from June 1940 on, and severely forbidding the cultivation of such varieties after March 1941—a ban that would endure in the subsequent decades in both West and East Germany.[43] To ensure enforcement of the law, Plant Defense Offices and local police were supposed to exert control over both farmers’ fields and the seed trade.[44] Neither in Italy or Portugal had seeds ever been banished from the commercial circuit, much less prevented from being cultivated. Also, the well-developed commercial seed market in Germany made commercial breeders much more important actors in the cleansing of the seed market than they were in Italy or Portugal. But it is more interesting that the release of new breeds was conditioned to the standards established by the Battle of Production. Potatoes that after having been tested at the BRA were considered as not contributing to the nutritional independence of the Volk didn’t have a place in Nazi Germany.
The short description given above already suggests the close proximity of BRA activities to the bureaucratic structure of the Reich in the Nazi years. If before 1933 the testing work put the BRA in direct relation with commercial breeders and the DLG, with the reorganization of agriculture by the Nazis that relationship was to be intermediated by the Reichsnährstand (RNS—Reich Food Estate), the mammoth Nazi institutional arrangement responsible for managing agriculture and food production. An account of the restructuring of the agriculture sector through the RNS is needed to better understand how laboratory work at the BRA related to the Nazi bureaucracy.[45]
33
A. Spieckermann and P. Kotthoff, “Die Prüfung von Kartoffeln auf Krebsfestigkeit,”
34
35
For an informed discussion on state interventions in the German seed market during the Nazi period, see Harwood, “The fate of peasant-friendly plant breeding in Nazi Germany,” pp. 580–581.
36
G. O. Appel, “Pflanzenschutz in der Landwirtschaft,”
37
K. Snell,
39
Here is the bureaucratic procedure for the approval of new varieties as it was described in 1933: Commercial breeders began by sending to the Potato Varietal Registry Commission at the Biologische Reischsanstalt in Berlin-Dahlem 20 tubers for the testing of the tuber and sprout characteristics, and later on 50 additional tubers for cultivation in field trials. Only after the undertaking of laboratory characteristic tests, which determined the inclusion of new breeds in the group of distinctive varieties, were tubers sent to field trials to compare their agronomic qualities with other varieties. The specimens for the sprout test tubers should arrive in Berlin-Dahlem by early February in order to have results by early fall; for field trials the samples should be sent by early April. Each breeder had the right to have three varieties tested for free, having to pay 20RM for each additional variety. Every year an average of 120 new varieties was sent for testing at the BRA, and only very few had the right to enter the Reichssortenlist. Sources: “Für die Prüfung von Neuzüchtungen von Kartoffeln,”
40
Anweisungen für den inneren Dienstgebrauch. Sachgebiet: Kartoffeln. Anerkennung von Saatgut durch den Reichsnährstand (1926–1937), BA/R3602/2239.
41
In 1930 the list included 141 varieties. See K. Snell, “Die Entwicklung der deutschen Kartoffelzüchtung in den letzten fünf Jahren,”
42
O. Schlumberger, “Die Erzeugung krebsfester anerkannter Pflanzkartoffeln in den Jahren 1934 und 1935,”
44
“Reichsnährstand,”
45
Here I follow Corni and Gies,