106 



BITTER PIT INVESTIGATION. 



there were also quite some from South Australia, and we noticed it also on Cleopatras from West 

 Australia. This Bitter Pit is a very serious question and is threatening the success of the industry, 

 and growers and shippers should unite in finding out if this disease could be prevented." 



The experiments now being conducted in cold storage have a very important bearing on this 

 point. When fruit is kept at a temperature of 30-32° Fahr. on the dry-air system, and free from Pit 

 when it is stored, it remains practically clean, that is to say, that if clean fruit is shipped, it should 

 arrive at its destination practically clean. There is scientific as well as practical sanction for this 

 statement. 



We have seen that the fruit, even when detached from the parent tree, still goes on respiring, 

 and the activity of this process is considerably modified by the temperature. There is a lower 

 limit, at or beyond which it seems to be suspended, although life is not destroyed, and, while this 

 limit varies in different plants, it is generally one or two degrees below the freezing point of water. 

 So the apple, at this temperature, is in a state of suspended animation, and any development of Pit 

 is retarded. 



There is no reason why fruit should not be carried at this temperature on board ship, and I 

 have the authority of one of the engineers for stating that the temperature can be kept constant to 

 within half- a- degree. I would strongly recommend that it become a regular practice in each 

 exporting State to have sample cases from each consignment placed in cold storage here and 

 compared with the condition of the shipment on its arrival in London. Both could be examined 

 about the same time (the arrival of the fruit ships being noticed in the daily press), and the 

 results obtained under known conditions compared with those from the conditions on board ship. 



As showing how Bitter Pit develops in ordinary storage, the following experiment is 

 instructive. 



Six apple trees of the variety known as Annie Elizabeth were selected at the Burnley 

 Horticultural Gardens for testing the amount of Bitter Pit present in the crop when ready for 

 picking, and the effect of keeping the fruit, which did not develop the disease externally while still 

 on the trees. The fruit was gathered on 4th March, and there were 237 apples altogether, of which 

 160 were pitted and 77 sound. The sound apples from each tree were placed in separate cases, and 

 kept in my laboratory. They were examined successively on 15th, 23rd, and 30th March, when 

 the diseased were removed, and the following is the result : — 





4th March. 



15th March. 



23rd March. 



30th March. 



Tree No. 





















Pitted. 



Sound. 



Pitted. 



Sound. 



Pitted. 



Sound. 



Pitted. 



Sound. 



1 



30 



12 



1 



n 



9 



2 



2 



0 



2 



25 



17 



3 



14 



10 



4 



2 



2 



3 



40 



6 



1 



5 



3 



2 



0 



2 



4 



30 



0 















5 



5 



3 



2 



1 



0 



1 



0 



1 



6 



30 



39 



0 



39 



18 



21 



4 



17 



Total 



160 



77 



7 



70 



40 



30 



8 



22 



Seven of thi apples, which were apparently sound when taken from the tree, developed 

 Pit in 11 days, 40 more in 19 days, and 8 in 26 days; so that there only remained 22 sound 

 apples at the end of the month out of a total of 77 at the start. 



The percentage of sound apples, while the fruit was still on the trees, amounted to 32.5, but, 

 after being picked and kept for nearly four weeks, it was only 9.2, or about 91 per cent, of the total 

 yield was pitted. 



