EFFECTS OF FROST OX THE APPLE. 



17 



however, without producing any such results, and the matter was left in a state of uncertainty. 

 " I hope this note may lead to the solution of this mysterious and so-called £ obscure disease,' 

 which, it will be seen, is one of considerable importance." 



Visiting the district of Orange in 1912, from which these apples were originally obtained, I 

 found the same disease in various orchards, and Fig. 45 shows twenty specimens of these deformed 

 apples taken from one tree. It was confined to one variety, Pomme de Neige, and, curiously enough, 

 this sort is blight-proof, or nearly so. 



Fortunately the Orchard Inspector for the district sent me a specimen of Pomme de Neige 

 on 30th November, when the fruit was about the size of walnuts, and it was the earliest 

 sample for the season of what looked like Bitter Pit, even although I was carefully watching 

 for the earliest trace of it in the Burnley Horticultural Gardens. It was photographed in 

 section (Fig. 47), and showed the brown spongy patches at the core as well as beneath the 

 skin. 



This " obscure disease " started at an early stage in the growth of the apple when the " core " 

 formed the bulk of it, for the flesh is merely a thin layer around it at first, as shown in Fig. 74. If 

 the conditions were favorable to the development of " pit " at this stage, it would naturally surround 

 and even encroach upon the core, and, as the apple continued to grow, more brown spots would be 

 developed beneath the skin, and thus they would extend from core to circumference. At this early 

 and tender stage, the brown spots practically surrounded the core, and the depressions on the 

 surface would be somewhat similar to that of " crinkle." 



In fact, it is just a form of crinkle starting at an early stage in the growth of the apple, and 

 causing the sunken and lumpy appearance. In the ordinary crinkle, as in ordinary Bitter Pit, the 

 injury is caused when the apple is comparatively advanced in growth, and it may grow beyond it, 

 so that the brown patches are inward from the skin, as well as immediately beneath it. But in this 

 instance the apples were actually stunted in their growth, and ceased growing on account of the 

 early attack. 



From the above consideration of *' crinkle " and this " obscure disease " of the apple, it will 

 be seen that they are just special forms of Bitter Pit. We have also seen that Bitter Pit may start 

 at various stages in the growth of the apple, according to the nature of the variety and the conditions 

 prevailing. In Early Red Margaret for instance, Bitter Pit was first observed this season on 4th 

 December, when it was approaching maturity, but distinctly noticed on most varieties when half 

 or three-quarters ripe. Crinkle was first observed in Five Crowns on 19th January, when about half 

 ripe. 



VII. — EFFECTS OF FEOST ON THE APPLE. 



It has been suggested that frost might cause this distortion and malformation, but, although 

 there is outward distortion the internal appearances are quite distinct. 



While visiting Harcourt, in Victoria, towards the end of March, I found that there had been 

 a severe spring frost about the end of October, and, while a number of the apples had been completely 

 destroyed, there were a number still on the trees. These, however, were variously twisted and 

 deformed on the side exposed to the frost, and invariably that side was much reduced compared 

 with the other. An extreme case is shown in Fig. 5°, where the deformity was around the " eye " 

 which was twisted round to the side, instead of being at the apex. When the frost is sufficiently 

 severe to reach the core and cause the pips to turn prematurely brown, then there is no further 

 growth of the apple ; but when it does not penetrate sufficiently deep, the apple continues to 

 grow. 



C. 10409. n 



