60 a EXPERIMENT STATION. [Jan. 



"Spindling sprout" of potatoes was reported from several 

 localities. The most severe case was noted in Field A of the 

 experiment station plots. This field is divided into eleven plots 

 for experiments to determine the relative value of different 

 sources of nitrogen. No difference was observed, however, in 

 the, severity of the disease on the different plots, and it is 

 extremely doubtful if the soil treatment bore any relation to the 

 trouble. Spindling sprout appears to be due to weakened vital- 

 ity of seed tubers. Whether the primary cause is always the 

 same is not known. It is conceivable, however, that either 

 unfavorable storage conditions, or the presence on the parent 

 vines of such diseases as late blight and Rhizociinia stem rot, 

 might be responsible for the condition. It is worthy of note 

 that the seed tubers from which the spindling sprouts developed 

 were to all outward appearances sound and healthy, and that 

 before planting they were treated with formaldehyde. That 

 the method of disinfection was not at fault is indicated by the 

 fact that a second lot of tubers from the same source as the 

 station supply, planted in another locality without disinfection, 

 developed the disease with equal severity. 



An unusual condition, difficult of explanation, existed relative 

 to the late blight of potatoes, caused by Phytophthora injestans 

 (Mont.) deBy. A wet June and July, with only five clear days 

 and the humidity above normal, presaged trouble, especially in 

 view of the very serious outbreak of the disease the previous 

 year. It was somewhat surprising, therefore, that compara- 

 tively little blighting of vines actually occurred. This may 

 probably be explained by the high temperatures during July 

 and August and scant rainfall in the latter month. Despite the 

 absence of vine blighting, tuber infection with Phytophthora was 

 unusually prevalent and severe, and heavy loss has resulted 

 from decay, both prior to and since storage. So general has 

 been tuber decay that market lots of potatoes free from the 

 diseases have been difficult to find. The writer has been 

 inclined to attribute this condition to mild infection during late 

 July and August (the period when vine blighting is normally 

 most severe), during which time conditions were such as to 

 retard development of the causal fungus, followed by abundant 

 rainfall, high relative humidity, and generally lower tempera- 



