160 EXPERIMENT STATION. [Jan. 



l^eriod of rather dry weather; and lalor in the fall there was 

 much complaint of celery hlight. Pear and apple blight were 

 nnusnally prevalent this year, more so than they have been 

 for some time. An unusually large number of samples of 

 pear and apple blight were sent in to the station for diagnosis 

 during the spring and early summer. More or less defoliation 

 of apple trees has occurred, resulting in part from the late 

 spring frosts, which caused blisters on the leaves ; and from 

 the use of spraying mixtures. 



A considerable amount of trouble is being experienced in 

 the defoliation of apple trees at the present time in various 

 parts of the United States, which is presumably caused by 

 spraying. Some of this trouble is to be found in our State, 

 and we surmise that it may be due in some cases to the use 

 of inferior Paris green in Bordeaux mixture, and in other 

 cases to the Bordeaux itself. The Baldwin apple spot has 

 been more or less prevalent during the past season, and some 

 trouble has been experienced from apple scab. 



A widely distributed and common trouble has occurred on 

 apple trees during the past season, which is termed sun scald. 

 This was more noticeable on small branches, particularly on 

 those which were shaded. This same diseased condition was 

 noticeable on other fruit trees, such as the peach and plum; 

 and on some wild shrubs, like the cornels. The effect of sun 

 scald was in some instances of an insignificant nature ; while 

 in others it resulted in a partial girdling of some of the 

 branches, which was followed by a poor development of the 

 foliage, and in some cases many of the twigs died. 



Sun scald is the result of a non-ripening of the wood ; and 

 it is significant that most of the branches affected with this 

 trouble are those hidden from the sun, which prevents the 

 wood from ripening as thoroughly as those which are exposed 

 to the sun. 



For the last two or three years sooty mold on the pear has 

 given rise to considerable trouble. This is caused by fungi 

 which grow in the honey-dew secreted by psylla on the leaves 

 and branches. As a consequence of this fungous growth, there 

 results a clogging of the pores of the leaves, which renders 

 them unhealthy, causing them to fall prematurely. The 



