30 THE BUSTS OF GRAINS IN THE UNITED STATES. 



cause of rust in grain. In February, 1782, he planted a barberry 

 bush in the middle of a wheat field. He states that a little before 

 harvest : 



The wheat was changing and the rest of the piece (about 20 acres) had acquired a 

 considerable degree of whiteness (white wheat), while about the barberry bush there 

 appeared a long but somewhat oval-shaped stripe of a dark, livid color, obvious to a 

 person riding on the roadside at a considerable distance. 



Marshall continues as follows: 



The part affected resembled the tail of a comet, the bush itself representing the 

 nucleus, on one side of which the sensible effect reached about 20 yards, the tail 

 pointing toward the southwest, so that probably the effect took place during a northeast 

 wind. 



At harvest, the ears near the bush stood erect, handling soft and chaffy; the grains 

 slender, shriveled, and light. As the distance from the bush increased the effect 

 was less discernible, until it vanished imperceptibly. 



The rest of the piece was a tolerable crop and the straw clean, except on a part which 

 was lodged, where the straw nearly resembled that about the barberry; but the grain 

 on that part, though lodged, was much heavier than it was on this, where the crop 

 stood erect. 



The grain of the crop, in general, was thin bodied; nevertheless, 10 grains, chosen 

 impartially out of the ordinary corn of the piece, took 24 of the barberried grains, 

 chosen equally impartially, to balance them. 



This experiment was repeated by Marshall hi Staffordshire with 

 similar results, and he became more firmly than ever of the opinion 

 that barberry was injurious to wheat. 



In 1787 Withering (106, p. 366) in speaking of Berberis vulgaris 

 repeated the statement which he made in 1776, already quoted 

 (p. 29). 



According to Windt (104), Schopf (93, p. 56) hi 1788 said that in 

 America the barberries in proximity to fields were blamed for injuring 

 grains and other field crops. Just how the injury was caused no 

 one could say. 



A severe epidemic of " mildew" took place in England in 1804 

 (84, p. 51). Arthur Young, secretary of the board of agriculture 

 at that time, issued a circular asking for information as to the cause 

 of "mildew" in wheat. In answer to the question "Have you made 

 any observations on the barberry as locally affecting wheat?" 

 numerous correspondents reported that injury resulted wherever 

 barberries occurred near a wheat field. According to the same 

 authority, Sir Joseph Banks (14, p. 521) in 1805 said: "Is it not 

 more than possible that the parasitic fungus of the barberry and that 

 of wheat are one and the same species, and that the seed is transferred 

 from the barberry to the corn?" 



In 1806 Windt (104, p. 8), from his own observations and experi- 

 ments, came to the conclusion that the barberry was the cause of rust 

 in wheat and that it acted as a center of infection. 



216 



