528 SECTIONAL TRANSACTIONS.—M*. 
Tuesday, September 29, 
Discussion on Fruit Storage Problems :— 
Dr. F. Kipp, Mrs. Onstow and Dr. C. West.—Physiological and Bio- 
chemical Aspects of Senescence in the Apple. 
Dr. T. Watiace.—Factors influencing the Storage Qualities of Fruits. 
In considering problems relating to the storage qualities of fruits, three main 
points call for attention, viz., susceptibility of the fruits to rots, the length of the 
period of senescence under natural storage conditions, and the effects of,special con- 
ditions imposed by artificial storage conditions of cold stores, gas stores, &c. 
The factors which predestine storage qualities of fruits may be grouped as follows : 
(a) Materials—including classes of fruits, varieties, rootstocks, age of trees. 
(6) Environmental Factors embracing 
i. Natural conditions, such as climatic factors; soil factors; incidence of 
disease organisms. 
ii. Artificial factors, 7.e. factors introduced by the fruit grower and merchant. 
The storage qualities of any sample of fruit are the resultant of these factors, but 
certain of the factors exercise dominant influences which enable storage behaviour 
to be foretold with some degree of accuracy. 
Various effects which have resulted from the undermentioned factors in storage 
tests carried out on numerous varieties of apples in an ordinary temperature store 
and in a cold store are described. 
Rootstocks ; age of tree ; deficiencies of nitrogen and potassium ; cultural systems ; 
pruning systems; fruit thinning; bark ringing; time of picking; size grading of 
fruits. 
The interrelationships between certain of these factors have also been established. 
The effects of the factors on the contents of certain ingredients of the fruits 
total nitrogen, acidity, reducing sugars, cane sugar, total ash and ash constituents 
have been determined and attempts made to correlate these with storage behaviour. 
Storage qualities do not show any simple relationship to the content of any of 
these constituents. 
Dr. A. 8. Horne.—Rotting in Fruit Storage. 
The two main factors influencing the occurrence and amount of wastage are 
infection and resistance to infection and invasion. 
Infection is of primary importance. In the case of orchards where fungal 
numbers are exceptionally high, apples from such orchards may show high mortality 
even when the fruit is moderately resistant. On the other hand, low fungal numbers 
and few pathogenic forms are often associated with low mortality in store, although 
the apples may be very susceptible to attack. 
Resistance to invasion is mainly conditioned by the following chemical factors : 
nitrogen content, acidity, total sugar content, proportions of the three sugars (glucose, 
fructose and sucrose) found in the fruit, and possibly potash content. Thus, low 
nitrogen, high acidity, high sugar content and high fructose or sucrose tend, in general, 
to increase resistance. 
The chemical composition of the fruit and consequently resistance may be modified 
by stock, manurial treatment and by ringing the tree. Thus, the application of 
sulphate of ammonia is found to increase the nitrogen content of the fruit and to lower 
resistance. 
Resistance of apples may be increased by injecting them with solutions of malic 
acid, cane sugar or various potassium salts. 
Dr. C. West and Dr. A. J. Smrra.—The Control of Atmospheric Conditions 
in Fruit Storage. 
In the preservation of fresh fruits two biological systems have to be considered— 
that of the fruit itself, a living system in senescence, and that of the microbial flora 
on its surface. Both can be profoundly influenced by modifying the atmospheric 
conditions in the storage chamber. 
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