BIO-CHEMICAL RESEARCHES ON BITTER PIT. 9 



This experiment, however, stands alone, and unconfirmed. No further batch of apples could 

 be procured clean, which pitted to any extent during subsequent keeping and observation. Gener- 

 ally, as mentioned, they remained uniformly clean, except for one apple, or at most two, showing 

 perhaps a single Pit or possibly two Pits. 



Should it be possible in a future year to confirm such a finding, then it would appear that either 

 the later stages in the development of Pit (i.e., those leading to its being distinctly recognisable to the 

 eye), are controllable, not only by low uniform temperatures, but also by high uniform temperatures, 

 or that Pit is particularly encouraged by high fluctuating temperatures. 



The experiment was never contradicted by any later experiment. 



The next lot of apples (Annie Elizabeth, Diamond Creek) kept from February 8th to March 8th 

 in three groups of 18 each : 



(a) At room fluctuation (68-80 F. for daily maxima) (51-66 F. for daily minima. 



(Argus Reports). 



(b) In moist air, 27-28 C. 80 to 83 F. 



(c) In dry air, 28-29 C. 83-85 F. 

 Gave : 



(a) 22% (b) 5-5% (c) 11% pitted. 



Some Cleopatras from Mr. Lang, Harcourt, gave for March 8th to April 12th under similar 



conditions : 



Room. Moist Oven. Dry Oven. 



(a) 20% (b) 20% (c) 10% (?). 



The batches consisted of only ten apples each, and therefore one apple pitted (plus or minus) 

 is all that is meant by the difference between 10 per cent, and 20 per cent. Also the apples are classed 

 as pitted on a single lesion, which is extremely rigid. 



More Annie Elizabeth apples in four groups of ten each under the same conditions as above, 

 but with one group kept in an atmosphere of Carbon dioxide at room temperatures (d) gave : 

 (a) 20% (b) 10% (c) 0% (d) 0% 



Generally speaking, the apples on the laboratory table seem to have shown a little more Pit 

 than those from the other group. 



It is not intended, however, to do more than point this out. It would be most incautious to 

 make any dogmatic deduction until clear confirmation on a larger scale be obtained. 



Should the point be subsequently fully established that fluctuating temperatures increase the 

 amount of Pit in apples, apparently plucked clean, then it will be necessary to establish a relationship 

 between the appearance of Pit and irregular metabolism in the apples. 



The ripening process is evidently going on the whole time, but with unevenness, and certain 

 cell groups may not adapt themselves sufficiently to the checks and accelerations constantly occurring 

 to retain their vitality in competition with their neighbours. 



Again, should there be ample confirmation of the effect of irregular ripening in producing Pit 

 in gathered apples, then irregular growth and ripening conditions, whilst the apple is still on the tree, 

 are all the more likely to be the causes of the trouble as the vital activity is then all the greater. 



It would, however, be premature from the relatively limited work of one season to make a 

 definite statement. All that can be said is, that with the material which passed through my hands 

 there was a distinct suggestion, either that regular ripening conditions protect the gathered apple 

 from the development of Pit, or that irregular ripening conditions produce Pit in the gathered apple. 



It appears to me that the former alternative should be considered the more likely, until at 

 all events fuller evidence can be obtained. 



Certain observations are called for with regard to the apples received for experimental pur- 

 poses. 



Out of 400 clean apples, for the most part of unripe appearance, those developing Pit under 

 observation numbered at most 30. Of these 30 the great majority were classed as unclean on a single 

 Pit or two pits. 



