1903.] PUBLIC DOCUMENT — No. 33. 29 



considerably injui'ed. The cold, wet season proved very 

 unfavorable to the melon crop, so that the vines readily 

 succumbed to disease. 



A-Sparagus Rust (^Puccinia Asparagi) . 

 Asparagus plants were affected by rust much less than in 

 previous 3^ears, demonstrating the influence of conditions of 

 weather upon this disease. 



Chri/santhemum Bust (^Puccinia Hieracii) . 

 The destructiveness of this disease, which has seriously 

 threatened the chrysanthemum, is evidently declining. 

 Cases of its occurrence have been very few this season, 

 and no serious damage has been evident. 



The Cucumber Mildeiv in Massachusetts (Plasmopara 

 Cubensis (B. & C.) Humph.). 



The general occurrence of this disease during the past 

 season upon cucumbers and melons calls attention to its 

 peculiar history in this State. The fungus was described 

 from Cuba many years ago, but was discovered in this 

 country in 1889, when it appeared in Massachusetts, New 

 Jerse}^ and other States at about the same time. In the 

 report of the Massachusetts Experiment Station for 1889, 

 Dr. Humphrey, then of this division, noted the occurrence 

 of the disease, calling attention to the serious damage which 

 its general distribution might cause. In subsequent years 

 this mildew became very prevalent throughout the southern 

 and middle States, causing great damage each 3^ear to cu- 

 cumbers and melons as far north as Long Island, but not in 

 New England. From this limited distribution it appeared 

 that the fungus required a somewhat warmer climate than 

 ours for its normal development. 



In the autumn of 1900 the downy mildcAv appeared again 

 in this State, being found upon greenhouse cucumbers in two 

 different localities, as noted in the report of this division for 

 that year. These were the only cases known at that time. 

 The next season the muskmelon crop all over the State was 

 quite generally affected and destroyed by this fungus, which 



