Cereals 279 



All cereal rusts multiply much more rapidly in damp 

 than in dry weather, and are more destructive to late crops. 

 There is no evidence that these maladies can be carried by 

 seed from rusted plants, though such seeds should not be 

 used for seed purposes, since they do not have stored nourish- 

 ment sufficient to give the seedling a vigorous start. 



Great difference in rust resistance has been shown; thus 

 while one variety of grain was so badly affected as to yield 

 only 23^ bushels per acre, a resistant variety under the same 

 conditions gave 383^ bushels. 



The greatest hope lies in the use of varieties which can 

 resist the disease. A number of different kinds of grain are 

 now known which possess sufficient resistance to give good 

 yields even when the rust is in its worst form. Since serious 

 outbreaks of rust must be looked forward to with certainty, 

 the item of rust resistance must have due weight in the selec- 

 tion of the variety to be grown. 



Several varieties of oats of the red group, among them 

 the Burt, Appier, and Cook when grown in the Southern 

 States, are known to possess valuable resistance to the oat 

 rust. Similarly there is large difference between varieties of 

 wheat as to rust susceptibility. 



Early maturity in oats is of especial value in that it enables 

 the plant to evade the heaviest part of the rust attack. Good 

 drainage and clean culture conduce to plants of more 

 resistance to rust, as does also good preparation of the seed 

 bed. Drilled wheat is better lighted and better ventilated and 

 resists rust more effectively than wheat that is broadcast. 



Wild grasses that harbor rusts identical with the rusts 

 of crop plants, such as wild meadow oat grass, orchard 

 grass, wild wheat grasses, quack grass, wild rye grasses, 

 etc., may propagate the fungus and increase infection. If 

 such grasses are rusted, they should be burned, plowed 

 under, or avoided in the location of the grain fields. 



While sprays of various kinds may be effective in checking 

 the spread of rusts, the use of such means of prevention is 

 impracticable, owing to the nature of growth of the crop, 



