CEREALS 



349 



all the kernels are wetted. The grain 

 should be left from ten to fifteen hours in 

 the solution and stirred several times dur- 

 ing the treatment. It may then be spread 

 and dried. 



For large amounts of seed it is better 

 to use a much stronger solution and for 

 a shorter time (1 gallon of stock solution 

 to 50 gallons of water for two hours). 



Covered smut, ustilagose ( Ustilago levis 

 (Kell. & Sw.) Magn.). — This differs from 

 the loose smut in the less complete de- 

 struction of the flowers and in its less 

 dusty spore masses, which are also blacker 

 than in the loose smut. The smut masses 

 are usually Umited to the parts within the 

 flowering glume and the palet or to the 

 bases of these. 



The treatment is that given for Ustilago 

 Avenas. 



Black stem rust {Puccinia graminis 

 Pers.). — The black stem rust on oats 

 shows but sUght differences from the black 

 stem rust of wheat, but that it is at least 

 racially distinct is indicated by the fact 

 that proof by inter -inoculation has not 

 been adduced and that a field of one of 

 these crops may be badly affected by its 

 fimgus, while adjacent fields of the other crop show no rust 

 or indication of infection such as they might be supposed 

 to do were the two rusts identical. 



Fig. 149. — Smut 

 {Ustilago l&ns) 

 on oata. After 

 Jackson. 



