360 POISONOUS AND EDIBLE FUNGI 



corn. On small qrains the disease is known by the common name 

 scab. The causal fungus is most frequently encountered in its 

 conidial stage, which is of the Fusarium type. As the cereal crop 

 approaches maturity, conidia of the Fusarium stage are present in 

 profusion at the surface of the grains and glumes. This fungus, 

 especially as it occurs on barley, has long been known to be 

 poisonous. The status of present-day knowledge of its toxicity 

 in connection with scabby barley is summarized in a report by 

 Christiansen and Kernkamp (1936). 



Long ago peasants in Russia found that scabby barley, when 

 used in bread-making or when fed to livestock, is toxic. In 

 northern Russia this toxicity came to be attributed to Fusarium 

 avenaceum (Fr.) Sacc, and in southern Russia, to Fusarium 

 gramineum Schwabe. In the United States about a dozen species 

 of Fusarium are known to be associated with barley scab. 



Barley scab was unusually abundant in 1928 in the Upper Mis- 

 sissippi Valley. Much of this diseased barley was used to feed 

 swine, and in consequence of complaints of sickness in the herds, 

 special efforts were made to learn more about the poisonous prop- 

 erties of Fusarium-affected barley. Some of the diseased crop was 

 exported to Europe, where similar complaints arose from its use 

 as feed for swine. The results of experimentation that was initi- 

 ated in the United States and in Europe leave no doubt that the 

 feeding of scabby barley is responsible for sickness among do- 

 mestic animals. In their entirety these experiments showed that 

 such barley is poisonous to horses, cattle, sheep, pigs, chickens, 

 and dogs, ruminants being able to tolerate greater proportions of 

 affected grains. 



Christiansen and Kernkamp (1936) observed that pigs refuse to 

 eat scabby barley unless they can get nothing else. If the propor- 

 tion of affected kernels is as much as 16° o, it is extremely toxic, 

 and if as much as 32%, the pigs refuse to eat it. Poisoning is 

 manifested by loss of appetite, listlessness, and weakness and 

 nausea; death may ensue. These investigators found that the 

 poisonous principle is v\ater-soluble and heat-stable. An aqueous 

 extract from 15 grams of scabby barley, when administered orally 

 through a stomach tube to a pig weighing 100 lb, caused vomiting. 

 An overdose of extract from Fusarium-infected corn caused 

 death. 



