358 DISEASES OF ECONOMIC PLANTS 



RYE 



Ergot (Claviceps purpurea (Fr.) Tul.)- — Ergot is widely 

 known as a black or purplish body, several times larger 

 than the seed of the affected plant, which displaces the 

 ovary or grain. Ergot occurs commonly upon rye and 

 wheat, and upon many other species of grass, as wheat 

 grass, wild ryes, bluejoint, Kentucky blue grass, Canada 

 blue grass, red top, timothy, and rye grass. Of the last 

 named, one farmer reports 1000 tons of hay so badly 

 affected as to be worthless. 



This disease is caused by the attack of a fungus upon the 

 ovary while the plant is in bloom. The fungus invades 

 and consumes the ovary and replaces it with the ergot, which 

 consists of a dense mass of tangled, interwoven mycelium, 

 a sclerotium. Ergots, when mature and under suitable 

 conditions, germinate, sending forth several stalks each, 

 with club-shaped, knobbed tops. From these the spores 

 issue to infect susceptible plants then in blossom. For 

 some days the fungus spreads from blossom to blossom by 

 means of other spores, and each infected ovary results in 

 another ergot. 



Loss to the grain and the damage to the plant are slight. 

 Chief injury from ergot arises from its effect upon the cattle 

 which eat ergotized grain or graze upon badly infected grass. 

 The effects appear in the spring; animals become emaciated 

 and rough haired as the result of continuous feeding of ergot 

 through the winter. Continued symptoms of ergot poison- 

 ing are tardy circulation in the extremities, gangrenous 

 sores upon the teats or mouth, and sloughing off of parts 

 of the tail, ears, or hoofs. Abortion may also follow as an 

 additional effect. 



