76 BITTER PIT INVESTIGATION. 



XVI. THE CONTROL OF BITTER PIT. 



The practical problem of Bitter Pit is not, as many suppose, the eradication of a pest. It is 

 the problem of growth "gone wrong," and we must study the mechanism of growth "gone right" 

 in order to control and prevent it. Hence the wide scope of the enquiry and the numerous experi- 

 ments necessary to deal with every phase in the growth of the tree and the proper development of 

 the fruit. 



It may be stated at the outset that there is no royal road to the control of Bitter Pit in the 

 growing fruit. There is no single operation which will ensure freedom from it, and there is no one 

 method of treatment which will satisfy all the requirements. From the constitutional nature of the 

 disease, and from its being located in the fruit, which is the final outcome of the tree's activity, every 

 factor which makes for healthy growth has to be considered. As the result of experiments, and from 

 the collective experience of practical orchardists, such measures may be recommended for adoption 

 as will minimize the effects of it. 



From the nature and mode of development of this disease it appears not only when the fruit is 

 growing, but also after it is picked clean and stored, so that the means of control have to be 

 considered both for the fruit on the tree and the fruit in store. 



CONTROL IN STORE. 



It was largely owing to the serious losses incurred in the over-sea shipment of fruit that this 

 investigation was suggested by the fruit growers. Thousands of cases of apples of the best varieties, 

 carefully picked and packed and visibly free from Pit, would be shipped under cool storage conditions. 

 On arrival at the other end the fruit would sometimes be so badly pitted and decayed as to be 

 unmarketable, and the grower would, in some instances, be actually out of pocket. This state of 

 affairs can now be absolutely prevented, and it lies with the shipping companies to carry out the 

 measures shown to be a perfect safeguard against loss from this disease. 



There is no fact more clearly demonstrated during the course of this investigation than that 

 when apples are kept in cool storage at a uniform and constant temperature of 30 to 32 degrees Fahr. 

 the development of Bitter Pit is retarded and the process of ripening is arrested. 



This ensures not only that apples can be carried without becoming pitted in transit, but that 

 they can be delivered at the same stage of ripeness as when placed on board. If these conditions are 

 not fulfilled, it is evident that the fault lies in the proper regulation of the temperature not having been 

 carried out. 



CONTROL ON TREE. 



While the fruit is still growing and receiving a supply of nourishment from the parent tree, 

 it cannot be directly controlled as when detached. But in the various operations conducted by the 

 intelligent orchardist there are so many possibilities of influencing the production of the fruit, that 

 through them a large measure of control can be exercised. How this control may be directed towards 

 the lessening of Bitter Pit will now be shown. 



When the crop is light and the relatively few apples are rather above the average size, the con- 

 ditions are favourable for the development of Pit. Therefore it should be the aim of the orchardist 

 to secure regular cropping and to have the fruit well distributed over the tree. 



When the fruit is mostly confined to the main branches, so that a strong flow of sap is directed 

 towards it, it is generally found that there the Pit is worst. On the other hand, when a limb was 

 cinctured so that the flow of sap was checked, the amount of Pit was reduced and sometimes entirely 

 prevented. Therefore, by a judicious system of pruning the fruit ought to be so distributed that 

 each will receive, as far as possible, a regular supply of nourishment so as not to be over-gorged. 



