SPRAYING EXPHKIMENTS AND APPLE DISEASES. 23 



It was the original plan of the owner to spray the trees 

 ■before the buds opened with a dormant spray of lime-sulphur 

 ■and again with the same material diluted to summer strength, 

 just before the flower buds opened, and a third time after the 

 petals fell. The first application was made about the first of 

 jNIay, using a 33° Beaume concentrate, diluted i part to 10 of 

 water. At this time the leaf buds on one row of 8 trees were 

 slightly in advance of the rest and were just beginning to open. 

 The owner fearing he would injure them omitted the applica- 

 tion of the strong spray upon this row of trees. However, the 

 remainder of the entire block received the dormant spray at 

 this time, and all received the two later applications. 



At the time the orchard was inspected, the leaves on the 32 

 trees to which all three applications of the spray were made 

 were exceedingl}- healthy, although scab was not entirely con- 

 trolled upon them. Those upon the 8 trees where the dormant 

 spray was omitted showed a strikingly different condition. 

 I^ully 75 per cent were attacked by scab and a large proportion 

 of these were quite severely affected. In fact only those of re- 

 cent growth were free from the disease. 



It is not the contention of the writer that spores of the perfect 

 -stage of the apple scab fungus, formed on the leaves of the pre- 

 vious year, are not the source of a great proportion, and usually 

 all, of the early spring infection of apple scab. It is, however, 

 maintained that, under certain conditions and with certain vari- 

 eties of trees, diseased twigs and water sprouts are an impor- 

 tant factor in the propagation and spread of the disease at the 

 beginning of the following year. It would also seem from our 

 observations that where limb infection exists the application of 

 some strong fungicide immediately before the leaf buds open 

 will greatly reduce the amount of spring infection from this 

 source. 



The European Apple Canker in Maine 



In an earlier publication of this Station it was stated that 

 while the European Apple Canker, caused by Nectria ditisstma 

 TuL, might be present in Maine it had not at that time been 



