DISEASES ISSOCIATED WITH BITTER PIT. 



29 



" The spot in no way resembles c Baldwin Spot,' which is always to be found affecting the 

 tissues beneath the epidermis, and which may go to a considerable depth in the flesh of the fruit. 

 The Baldwin Spot is a physiological trouble, and is due to the abstraction of water from the cells. 

 In the Baldwin Spot the epidermis usually remains intact, although the cells beneath it may have 

 become disorganized. 1 ' 



X. — DISK ASKS ASSOCIATED WITH BITTER PIT. 



In calling attention to the diseases found associated with Bitter Pit, my object is not only 

 to guard against their being confused with that disease, but mainly to show that the conditions 

 favouring the one are not antagonistic to the other. The four principal diseases found by myself 

 were — (1) Black Spot, or "Scab," caused by a fungus known in its parasitic stage as Fusicladiani 

 dendriticum (Wallr.), Fckl. ; (2) Bitter Rot, known in the summer stage as Gloeosporium fructigcnum 

 Berk. ; (3) Glassiness, or Water-core ; and (4) Mouldy core, due to a common mould. 



BLACK SPOT, OR SCAB. 



In the early stages of this disease, when the spots are minute and scattered over the fruit, 

 it is sometimes mistaken for Bitter Pit, more especially when associated with it. It is not uncommon 

 to find the two diseases together, favoured by the same climatic conditions, although the Black 

 Spot may be on one portion of the fruit, and the Bitter Pit on another. In Australia the 

 orchardist is generally familiar with the appearance presented by Black Spot, and recognises it 

 as such, but in South Africa Lounsbury (50) states that the two are commonly confused. 



In Black Spot not only is there an evident fungus causing it, the velvety growth on the 

 blackish spot consisting of spores, but the blemish is confined to the skin, whereas in Bitter Pit 

 there is no fungus growth, and beneath the skin the pulp is found in spots to be brown, dry, and 

 tough. (Fig. G2.) 



BITTER ROT. 



I have found this disease occasionally associated with Bitter Pit. (Figs. 63, 64.) As 

 the name denotes, the taste of the affected tissue is bitter, but just as in Bitter Pit, it varies from 

 a pronounced bitter taste to one which is hardly distinguishable. The infection by the fungus 

 usually starts at one or a few places, but it sometimes occurs at numerous spots scattered over the 

 surface. It is then superficially not unlike Bitter Pit, since the spots may become depressed, 

 owing to the shrinkage of the affected pulp beneath, and at first there may be no external growths 

 of the fungus. But, with the characteristic development of the fungus, as shown in Fig. 65, there 

 is no longer the slightest resemblance. The spore-pustules are arranged in concentric rings, from 

 which the spores ooze out in pinkish masses, and soon dry up. 



GLASSINESS, OR WATER-CORE OF THE APPLE. 



This is also a disease due to internal causes, but its symptoms are quite distinct from those 

 of Bitter Pit, and the two have only been found associated together on rare occasions. Its 

 appearance is familiar to the orchardist, and it is most frequent in wet years, especially if the rain 

 occurs about the time the fruit begins to ripen. Large varieties, with hard, firm flesh, are most 

 subject to it, and early varieties rather than late. In Victoria, among the worst are Mela Carlo 

 Stone Pippin, and Stewart's Seedling. In the former variety particularly, it is difficult in some 

 seasons to get a single apple off a tree entirely free from it. In the Burnley Gardens the disease 



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