2 I 



No. 5 ; No. 9, 3 lbs. Dissolved Bone-black, applied at intervals. Half of 

 each bed was set with Semple Asters and half with O^een of the Market. 

 On other beds a liberal dressing of lime was given, in addition to stable 

 manure, on still others wood ashes, complete fertilizers and manure alone, 

 etc., etc. 



Observation and inquiry show beyond doubt that 



Weather the prevalence of this disease varies in different 



Conditions, seasons, though in a broad and general way, the 



conditions prevailing in one year are apparently 

 more conducive to it than those in another. Thus in 1899 this 

 trouble was much more common than in 190 1, even on land planted 

 each year in asters. 



For various purposes during the course of these 

 Plants in Pots, investigations, plants have been grown in large pots, 

 Benches, Etc. elevated boxes of earth, greenhouse benches, and 



similar situations. It was early noticed that the 

 yellow disease seemed very much less abundant in such plants than 

 in others of the same lots growing near them in the soil. Inquiry 

 among gardeners revealed the fact that others had noticed the same 

 peculiarity. Asters for the early market are not infrequently grown 

 in greenhouses, and so far as our observation goes, the disease is 

 practically unknown under such conditions, though plenty enough in 

 the open ground near by. Without doubt there is in this respect a 

 marked difference in the prevalence of the disease. We have grown 

 many plants in large box trucks, and in these the only trace of the 

 yellow blight that has ever appeared has been a very little in a few 

 of the last rtowers of the season. The chemical and physical prop- 

 erties of the earth in these trucks and in many pot experiments have 

 varied widely, but these features have shown no relation to the dis- 

 ease. It is difficult to see how the simple change from the open 

 earth to a pot or bol can produce such marked effect, but certainly 

 it is exerted by some obscure influence. 



FURTHER CONSIDERATIONS. 



Vll the study and observation of this disease go to show that it is 

 due to an obscure perversion or derangement of the vital functions 

 of the plant. That the trouble is so generally prevalent on all kinds 

 and conditions of soil and is unaffected in its occurrence by any of 

 the widely varying influences enumerated above, seems sufficient to 



