16 BITTER PIT INVESTIGATION. 



It appears that in America there is not the same clear-cut distinction as there is with us between 

 the effects produced by insect punctures and a non-parasitic disease such as Bitter Pit is acknowledged 

 to be. It becomes necessarv, therefore, to clearly define the disease we are dealing with, and endeavour 

 to carefully exclude whatever other diseases might be mistaken for or confounded with it. This has 

 been done by the above-named authors in the following description of Stigmonose of the apple : 

 "Stigmonose is used lo refer to responses to insect attacks. In certain cases the effects on apples 

 can scarcely be distinguished from Bitter i'it. The development of some form of this trouble seems 

 to be closely associated with the occurrence of the Rosy Aphis [not known in Australia]. It differs 

 from Bitter Pit in that it develops earlier in the season, that it occurs on the fruit that is in the middle 

 of the tree rather than that on the exposed limbs, that it is often followed by cracking of the fruit and 

 premature ripening, is often accompanied by a corrugated gnarled appearance of the apple, that the 

 spots are not typically at the ends of the vasculars, that the brown tissue beneath has more definite 

 margins, is more nearly spherical in shape, and is firm rather than spongy." 



In Australia there is no comparison or chance of confusion between the punctures of insects and 

 Bitter Pit, as shown in Figs. 31. 33. In America the two are often confounded, although the genuine 

 Bitter I'it is acknowledged to be prevalent. In Franco, as we have seen, there is a tendency to 

 attribute all such symptoms as are exhibited by Bitter Pit to sucking insects. 



BITTER PIT CONFOUNDED WITH BITTER ROT. 



References to Bitter Pit in horticultural literature are sometimes rather startling, because the 

 nature of the disease i.s evidently misunderstood, and it is confounded with some other disease with a 

 name somewhat resembling it. 



Thus in The Sweet Pea Annual for 191(5, edited by J. S. Brunton, F.R.H.S., it is stated: 

 ''Now what connection have the fruit trees with disease ? Anthracnose is the self -same disease that 

 causes 'Hitter Pit" in apples. The disease can be transferred from apples to sweet peas or vice versa." 

 A leading orchardist brought this statement under my notice, and it was very easily disposed of. 

 Anthracnose or "Bitter Rot" of the apple is due to the fungus Glomerella rufo-maculans (B.) >Sp., and 

 since there is a sweet pea anthracnose due to the same fungus, the same disease is common to both, 

 only "Bitter Rot" has been mistaken for Bitter Pit, and hence the mistake. 



The disease of Bitter Pit is now regarded by all the investigators who have made a special study of 

 it as non-parasitic in its nature, being due neither to insects nor fungi, and the foregoing account 

 shows how indispensable it is to determine the proper cause of a disease before attempting to prescribe 

 remedies or recommend preventive measures. 



IV. THE FRUIT-BUDS OF THE APPLE TREE. 

 THEIR POSITION, ORIGIN, PERIOD OF FORMATION, AND TREATMENT. 



The seed and the bud are the two organs which either originate the tree as a whole or portions of it. 

 The bud is an undeveloped or incipient shoot , and may either give rise to the ordinary leafy branch or 

 to flowers. The buds which develop into leafy shoots are known as leaf-buds, or wood-buds as they 

 are often called, because they produce the new wood. The buds which develop into flowers only are 

 known as blossom-buds, but the orchardist speaks of them as fruit-buds, because it is from them the 

 fruit is obtained, in contradistinction to the wood-buds which provide new wood for future fruit 

 bearing. 



We will confine our attention to the buds which produce flowers, or the fruit-buds, and they are 

 recognized as being larger, plumper, and blunter than the wood-buds. 



