50 Director's Repobt of the 



It was not definitely determined that annual spraying would be 

 profitable during a series of years because the blight does not 

 attack the potato plant every season and when this disease is not 

 prevalent, spraying is less necessary. The year 1911 was 

 the tenth year of this experiment and there follows later a sum- 

 mary of the results, showing that the average results for the ten 

 years indicate a material net profit from the annual spraying. 



During recent years, the attention of the Station has been called 

 to a very prevalent disease of fruit trees known as the '' crown 

 rot." In all sections of the State much loss has been caused by 

 this affection. Various explanations have been offered, such as 

 the attack of a fungus, and arsenical spraying. Extended investi- 

 gations by this Station have led to the conclusion that this disease 

 (if it may be called such) is due chiefly to winter injury. xVn 

 account of the investigation is given in Technical Bulletin No. 23 

 of which a summary is given on p. 561. 



The Botanical Department of the Station has demonstrated its 

 usefulness in maintaining a very careful survey of the plant 

 diseases prevalent in the State. As an illustration of the value 

 of the watchfulness that has been maintained, this Department 

 first called attention to the existence of the currant rust in this 

 country, doubtless imported from Europe. This disease caused 

 great damage to pine forests in other countries and it has been 

 found necessary to destroy thousands of imported pine trees that 

 were affected with this pest. More recently, it has been found 

 that the currant rust is now well distributed in portions of Isew 

 York in currant plantations and this matter will require the most 

 careful attention by the State to prevent serious loss from its 

 possible spread to our pine forests. 



The Botanical Department has also been asked to advise in the 

 matter of controlling that most destructive disease, the chestnut 

 blight, which is causing the death of large numbers of chestnut 

 trees, particularly in Pennsylvania and in certain sections of Xew 

 York. The head of this Department has united with other 

 specialists in urging that much more study must be given to the 

 life history of the disease and to the manner in which it is spread 



