96 Report of State Board of Horticulture. 



Owing to the late date at which apple harvest continues, it is some- 

 times true that the autumn rains make the soil so loose and muddy that 

 it is impossible to apply a spray following the gathering of the fruit. 

 In such cases there are other practices which may be followed with good 

 success. A thorough spraying of Bordeaux mixture before the buds 

 begin to open during the spring and while the entire tree is exposed to 

 the direct drive of the spray the trees have been so thoroughly coated 

 that the amount of Bordeaux mixture remaining on the trees throughout 

 the seasons, including the following autumn, was sufficient to give as 

 good results as could be gotten by spraying at any other date. These 

 phenomenal results are less wonderful since it is now known that the 

 old cankers two years of age are the seat of a second set of spores 

 thrown off the second season and capable of starting new infections. This 

 early spraying admits of thoroughly söaking these old cankers, which 

 if in a dry condition have been observed to become a deeper blue color 

 on the application of Bordeaux mixture, the di-y and dead bark absorbing 

 the liquid like a sponge. 



In the cleaning up of any orchard of trees that have become badly 

 infested with the disease it is advisable to tear out the bark from all 

 cankers after the cankers of the present year are mature in size. Each 

 wound should also be coated with thick Bordeaux mixture, since through 

 experiments conducted by the writer, it is evident that the fungus will 

 thrive in the wood as a saprophyte as well as in the old and dead bark 

 previously killed by the fungus. In case time will not admit of remov- 

 ing the bark the cankers should be thoroughly plastered with the spray. 

 Cutting out the growing cankers may also be done and is advisable 

 when the condition of the orchard will admit of such a practice. In 

 cutting out the cankers on badly infested trees very frequently more 

 injury is done in doing the work than the fungus would do if left to com- 

 plete the season's growth. 



The timing for spraying infested trees depends upon several important 

 orchard practices and it is therefore very important that the timing 

 should be carefully considered. Anticipating loss from the rot, which 

 is sure to follow when fruit is exposed to the spread of spores during 

 the last part of summer and early autumn, the most logical method of 

 meeting the Situation is to apply a spray before the fruit is gathered 

 in order to kill the spores adhering to the apples. In making this 

 application it is not necessary to use a very strong spray, since the 

 weaker mixture (4-4-50 Bordeaux) carries a far greater per cent of 

 the killing properties than are actually required to do the work; besides 

 the coating of the apple is only temporary, serving to protect the sur- 

 face of the fruit until it has been placed in the warehouse or packing- 

 house from which the fruit is packed following the wiping of the same, 

 a practice which apparently pleases the consumer, although not to be con- 

 sidered at all necessary when considering the action of the spray 

 ingredients on the keeping qualities of the fruit. Another consideration 

 relative to the application of autumn sprays to control this disease is 

 the partial destruction of the scab fungus which at this time is apt to 

 be very abundant on the foliage. It is apparent from field observations 

 and experiments that the coating of spray left on the leaves ckiring the 

 fall spraying that the active principles of the ingredients applied do 

 act favorably in at least lessening the spread of the fnngus the follow- 

 ing spring. 



Since it is less difficult to spray a tree after the fruit has been 

 gathered, it is generally advisable that the autumn spray follow the 

 gathering of the fruit. In cases of light infestation only one spraying 

 is necessary. When the disease is abundant, however, two applications 



