11»0(k] public DOCUMENT — No. 33. 141 



1801), and it has always been widely distributed. Any bed 

 whicli has become once infected with tliis stage remains so, 

 but fortunately the damage occurring from teleutospore in- 

 fection is insignificant, and in the majority of cases not 

 discernible. Asparagus rust lias now become quite well 

 distributed over the United States, but its virulence does 

 not show itself in the same degree for every locality, and 

 the problem of control is by no means everywhere the same, 

 since factors enter into the problem which do not possess 

 the same significance for all locations. In this State rust is 

 most intimately associated with lack of vigor, and more 

 particularly with those factors which underlie vigor, such 

 as supply of water and judicious fertilizing. For this reason 

 the most efficient remedies are based upon those practices 

 the application of which induce vigor. There are a number 

 of remedies which can be api)lied, some of which have given 

 excellent results. Thorouo-h cultivation and fertilization 

 in more than one instance have given results which have 

 proved superior to any other method of treatment. We 

 have observed that the results from weekly cultivation com- 

 bined with judicious fertilization have proved very satis- 

 factory. Irrigation has also proved very eftectual during 

 dry seasons ; but there is possibly a tendency for asparagus 

 to become too succulent with repeated irrigation, which 

 might possibly render the })lant more susceptible to infec- 

 tion. 



We also believe that an efficient practice pertaining to 

 rust infection consists of burning the old brush in the fall, 

 since a large number of teleutospores are destroyed, which, 

 if left remaining in the ground over winter, would germinate 

 freely in the spring and constitute a dangerous source of 

 infection. We have repeatedly attempted to germinate 

 teleutospores in the early winter, but failed. They will 

 germinate freely in jVIarch, however. Moreover, the roots 

 from infested plants, when transplanted in the greenhouse 

 in the fall and left there for a year and allowed to develop 

 tops, have never shown any tendency to rust. This would 

 seem to indicate that not only is a resting period essential, 

 as is usually the case for spores, but freezing also is essen- 

 tial. We are of the opinion that most beds are infected in 



