8 



part of the country. The pears were also unusually russety. 

 It seems possible that the russety surface due perhaps to frost 

 presented an unfavorable condition for the development of the 

 scab fungus, aud thus in a measure protected the fruit from its 

 injuries. 



POTATOES 



In the case of potatoes the experiments were directed chiefly 

 towards the prevention of the Early Blight and the Scab. 



The following description of the early blight is reprinted 

 from the New Hampshire College Experiment Station Bulletin 

 No. 22. 



EARLY BLIGHT 



The early blight ( Macrosporimn solani ) has come to be rec- 

 ognized as a serious disease of the potato only within the last 

 two or three years. It was first noticed at this station in the 

 summer of 1892. As its name indicates, it makes its appear- 

 ance earlier than the ordinary blight — by the middle of July or 

 earlier. It first appears, as sharply defined, rather irregular, 

 dark brown or blackish spots on the leaves. The surface of 

 the spots is usually marked with minute wrinkles, which take 

 roughl}' the form of numerous circles with a common centre; 

 this has been called the '•'target marking," from its resemblance 

 to the concentric rings of a target. The spots increase gradu- 

 ally in number and size till the whole leaf is destro3'ed. 



The fungus producing this disease differs considerably in the 

 details of its structure from the late blight, but like it, consists 

 of mycelial threads which grow in the tissues of the leaf and 

 send out spore-bearing stalks on the surface. The early blight 

 may be distinguished from the late blight by its characteristic 

 spots, l)y the absence of the mould-like growth on the under 

 side of the leaf in the case of the latter, by its earlier appear- 

 ance and slower growth, and by the fact that it does not aflfect 

 the tubers. 



The experiments against the early blight wore made in the 

 Station potato field. On Jul}' 7, plots aggregating one and one- 

 sixth acres were sprayed with Bordeaux mixture. Alternate 

 plots aggregating four-fifths of an acre were left unsprayed 



