22 a EXPERIMENT STATION. [Jan. 



winter rye. This was plowed under in the early spring of 1907, 

 when the asparagus was set. 



It seems quite possible that the thorough preparation which 

 the land received and the fact that so large an amount of 

 vegetable matter was incorporated with the soil before the 

 plants were set account for the exceptionally favorable compara- 

 tive results from the application of commercial fertilizers alone. 



9. Relation of the Fertilizer Treatment to Rust. — The fact 

 that there has been but little rust in the Concord asparagus 

 district during the past three years has undoubtedly consider- 

 ably reduced our chances for determining whether there has 

 been any direct effect upon the extent to which rust has af- 

 fected the crop which can be attributed to variation in fertilizer 

 treatment. The results of our study of this question, however, 

 which, as will be understood, must be a matter of judgment 

 based upon careful inspection, convince us that the location of 

 the different plots in relation to direction of prevailing winds 

 w^hich might carry rust spores from centers of infection outside 

 the experimental field has had much more to do with the extent 

 to which rust has affected plants in the different plots than 

 variation in fertilizer treatment. Most careful observations, 

 however, by two different observers working independently have 

 led to conclusions as to the relative amount of rust in different 

 plots which are in substantial agreement. These conclusions 

 may be thus stated: the application of nitrate of soda at the 

 close of the cutting season promotes a vigorous growth and 

 seems to increase the capacity of the foliage to resist rust; at 

 least, two observers have agreed that there is less rust on plots 

 to which nitrate of soda is applied at the time indicated. This 

 is true whether the nitrate is applied one-half in the early spring 

 and the balance at the close of the cutting season, or all at the 

 close of the cutting season. 



While, therefore, for the reasons first pointed out, it has been 

 a matter of great difficulty to determine whether there has been 

 a connection between the amount of rust and the fertilizer 

 treatment, I am strongly inclined to believe that the applica- 

 tion of a moderate amount of nitrate of soda, perhaps 150 to 

 200 pounds per acre, at the close of the cutting season is likely 

 to reduce the amount of injury from this disease. 



