Forage Crops 339 



The rust is destructive, but seems to be limited to this one 

 host. 



Smut. See timothy. 



Anthracnose. See rye. 



Minor diseases are caused by Uromyces pace Rab., Phyl- 

 lachora poce (Fcl.) Sacc, and Ergot. 



CRABGRASS 



Blast {Piricularia oryzce Cav.). — This is probably iden- 

 tical with rice blast. See p. 300. 



JOHNSON GRASS. See sorghum, p, 307, which has similar 

 diseases. 



MILLET. See p. 295. 



ORCHARD -GRASS (Dactylis) 



Leaf-spot {Scolecotrichum graminis Fcl.). — Elliptical, 

 dead spots may appear upon orchard-grass and on several 

 other grasses, conspicuous upon the lower outer leaves. 

 Death of the leaf follows sometimes, starting at the leaf tips 

 and reaching to the base. In conditions favorable to the 

 disease whole plants are involved. The spots, before they 

 become confluent, are of quite characteristic appearance: 

 large, dark brown to purplish brown. When old, they usually 

 show at their centers spots of gray or white, and these spots 

 may be marked with small, black specks arranged in rows 

 lengthwise of the leaf. 



Black-stem-rust (Puccinia graminis Pers.). — This rust 

 fungus may be either of the oat, orchard-grass, or Agrostis 

 strain. 



Crown-Rust {Puccinia coronata Cda.). — See oats, p. 298. 



Anthracnose. See rye, p. 307. 



Rathay's disease {Bacterium rathayi (EFS.) ) ^''^ develops 

 'with thick layers of bacteria on the surface of the plant, 

 causing an unusual type of plant disease. 



