256 MASS. EXPERIMENT STATION BULLETIN 194. 



10. The lack of benefit wliich can be attributed to humus furnished 

 by the manure may be explained in part by the practice of our commercial 

 asparagus growers in allomng the tops grown subsequent to the cutting 

 season to remain on the ground to be worked into the soil the following 

 spring. 



11. The conclusion appears to be justified, through observations upon 

 the root habit of the asparagus, that yearly replacement of roots used 

 when relatively young for the storage of reserve material by younger 

 roots is also an important factor in accounting for the lack of beneficial 

 effects resulting from humus furnished by manure. The roots thus 

 replaced decay, thus adding to the organic matter of the soil. 



12. The season of appHcation of nitrate of soda does not appear to 

 affect the relative yield of commercial asparagus in successive ten-day 

 periods throughout the season; in other words, the cut of commercial 

 asparagus during the early part of the season is not increased by either 

 small or large applications of nitrate made as early as the soil can be 

 worked. 



13. The season of application of nitrate of soda does appear to influence 

 the susceptibility of asparagus to rust, which I am convinced is reduced 

 by the application of at least a portion of the nitrate of soda at the close 

 of the cutting season. 



14. The character of the season, especially the amount and distribution 

 of rainfall, appears to affect the probability of a serious attack of rust to 

 a considerable degree, such attacks being more common in dry seasons 

 than in those characterized by normal or abundant and well-distributed 

 rainfall. 



