Fascist Pigs: Technoscientific Organisms and the History of Fascism

The virus group (called the physiologic botany section of the botany department in 1934, and renamed the plant virus pathology section in 1943) was led by Erich Köhler, who had begun his career at the BRA in 1921 doing research on wart disease and then had turned to plant virology in 1932.[107] Köhler was celebrated for having introducing into Germany the notion—already in vogue in the Netherlands and the United States—that viruses were the pathogenic agents responsible for potato degeneration (Kartoffelabbaus), in contrast to ecological theories arguing that potato leaf roll was caused by environmental factors such as water imbalance.[108] In fact, the cause of potato degeneration was, from very early on, a major issue at the BRA, Otto Appel himself having published a leaflet on leaf roll differentiating it from the crinkle of the potato and making no mention of viruses. The concern about degeneration is not surprising. The yields of contaminated fields, according to the BRA numbers, were reduced by between 25 and 50 percent in the first year, and by more than 60 percent in subsequent years.[109]

In accordance with its usual approach, the BRA proposed a method to identify infected seeds so as to guarantee the distribution among German farmers of healthy material from commercial breeders. More important than maintaining old varieties in a virus-free state was to ensure that new seedlings that were hoped to be resistant to late blight would not be exposed to viruses in their early stages of multiplication. For this Köhler proposed the Stecklingsprobe (a variation of the Tuber Index Method developed by American scientists at Cornell University), which entailed removing and growing a seed piece from each individually numbered tuber selected from a stock.[110] The plants grown from these seeds were then observed for the presence of viruses. When the presence of a virus was confirmed, the diseased tuber was discarded. Only tubers corresponding to healthy plants were reproduced. Two central elements of the method are now familiar: careful recording of each tuber and the respective plant and allocation of greenhouse space for the quick growth of potato plants shortly after the harvesting of potatoes.

The main challenge presented by the method was detecting the presence of viruses quickly. If in some cases viruses manifested themselves through obvious leaf symptoms in an infected potato plant, latent viruses were made visible by rubbing tobacco plants with sap from the tuber seedlings.[111] From 1932 on, Köhler tinkered at the BRA with different combinations of viruses, potato varieties, and test plants, aiming to come up with an effective way of identifying viruses so as to guarantee the health of the certified stock seeds to be used by peasants.[112] Different test plants were tried for different types of viruses.[113] In addition to tobacco and pepper plants, the wild variety Solanum demissum was also found to be an effective test plant for the main types of viruses.[114]

^{Figure 3.10 The title page of the proceedings of a 1943 conference held by the Biologische Reichsanstalt für Land- und Forstwirtschaft. Note deletion of the swastika under the imperial eagle in this copy.}

^{(Virustagung der Biologischen Reichsanstalt für Land- und Forstwirtschaft am 23 januar 1943, Paul Parey, 1943)}