20 



he admit that mildew on Humulus is caused by night;=£rost or fog; 

 "For, if so," says he, "why should not all the plants next to the hop be 

 affected by mildew at the same time?" The chapters of his book treating 

 of the damaging effect of frost, cancer, noxious insects, wounds and 

 their treatment are excellent, and it is only to be regretted that his 

 work should so quickly have been forgotten. I never saw it quoted 

 by any of his successors, and the superstition advocated by Gleditsch 

 and others, and fought by Fabricius, soon again predominated and 

 continued to rule almost up to the time of Rostrup. The well^intended 

 attempts of Fabricius to instruct the farmers of the true causes of the 

 diseases of the plants were premature, the number of freeholders was 

 too small at that time, all fields belonging to a village were coopera* 

 tively cultivated, there was too httle interest in increasing the yield, 

 and it was not until the complete change of the social state at the 

 end of the 18. century that phytopathology commenced to be of im* 

 portance to the farmers. 



For this reason- the same Oeder, who has been of so great signifl* 

 cance to mycological investigation in Denmark by giving the impulse 

 to the publication of the "Flora Danica" also — if not quite so 

 direct — became of significance to the phytopathology of this country 

 by his skilful agitation for the emancipation of the peasants. 



For as, in 1788, Bernstorff, Schimmelmann and other patriots had 

 succeeded in carrying out the plan for which Oeder had worked so 

 ardently, to emancipate the peasants from villenage and abolish the 

 joint cultivation of the fields, an interest was aroused among the far* 

 mers to increase the yield of the fields, and it was a matter of course 

 that this should induce several farmers to deal with the diseases which 

 decreased the yield of the cornfields. 



In the agricultural periodicals of that time: "Nye landekonomiske 

 Tidender", "Kgl. Landhusholdnings Selskabs Skrifter" and "Olufsens 

 oekonomiske Annaler" we therefore find many articles by clergymen 

 (who were at that time also always farmers), schoolmasters and common 

 farmers on smutted corn and other conspicuous diseases. Then there 

 was much superstition as to the causes of the diseases of the plants, 

 and there was no understanding whatever of the significance of para;! 

 sitic fungi to the diseases of the plants. For instance we find that Esaias 

 Fleischer in his "Agerdyrkningskatekismus" (Agricultural Catechism) 

 writes: "The cause of smut is certainly no other than unripe grains," and 

 that Gregers Otto Begtrup (born 1769, died 1841 ; at the beginning 

 of the 19. century professor of agricultural economy and one of the 

 most experienced men in agriculture) mentions the different liquids 

 for the steeping of grain (1800 ^°*) recommending farmers to use them 

 as "they are useful to the grain especially to the wheat", but the work 



