1917.] PUBLIC DOCUMENT — No. 31. 33 a 



as in recent years. While few diseases which are new to the 

 State have come to our attention, a number which are quite 

 unusual appeared during the past year, and several which are 

 generally of minor importance became much more serious than 

 usual. 



In the first class belongs anthracnose of the English elm 

 {Gloeosporium inconspicuum Cavr.). An unusual number of 

 other shade-tree diseases caused by other species of Gloeosporium 

 were prevalent, affecting, among possibly others, the Norway 

 maple, white oak, red oak, sycamore or plane tree, beech, 

 American elm, English elm and Lombardy poplar. 



"Spindling sprout" of potatoes so seriously affected one of 

 our experimental fields as to make it apparent that the results 

 would have no direct evident relation to the points under in- 

 vestigation, and the field was plowed up. The causes of this 

 disease are more or less obscure, but are probably connected 

 with weakened vitality of the seed tubers. 



The observations of the year make it apparent that white 

 pine blister rust exists in every county of the State except Nan- 

 tucket, and that it is most abundant in the extreme eastern and 

 extreme western mainland counties. The different species of 

 Ribes are very generally infected, and the observations made 

 seem to afford some ground for believing that the fungus caus- 

 ing the disease, at least under some conditions, is able to sur- 

 vive the winter in Ribes. 



In a number of localities white pines have suffered from an 

 unusual injury noticed in various parts of this State and in a 

 number of near-by States. The first evidence of the trouble in 

 question is the dying of the young needles, which usually begins 

 at the tips, though not invariably. The needles in most cases 

 ultimately dropped, leaving the new shoots bare below the 

 terminal tuft of needles which developed subsequent to the 

 period of injury. It is believed that this trouble was due to 

 the meteorological conditions which prevailed in June when 

 the young needles were partly grown, that month being char- 

 acterized by extreme humidity. 



Hothouse cucumbers suffered to an unusual extent from 

 downy mildew, a condition believed to have been favored by 

 the wet weather of the latter part of September, in which it 



