BROWN HEART IN APPLES

New Zealand Times, Volume LII, Issue 12096, 25 March 1925, Page 11

BROWN HEART IN APPLES

TREATMENT OP DISEASE. The conditions giving rise to "brown heart" in apples in cola storage are not j likely to occur except under exceptional circumstances, when the storage chambers have relatively -gas-proof walls ancl when no ventilation is given, Such conditions, however, occur in ships' holds, and the "gas" storage method is used. In the case of carriage of apples in refrigerated holds on voyages of several weeks' duration 'three main sVstems of refrigeration are employed. > These are usually spoken of; as the "battery" system, the "qold air" system, and the "grid" system. In the first two systems forced air circulation is employed, which incidentally Erovides considerable ventilation of the olds. In the "grid" system, on the other hand, there is no forced air circulation, and the ventilation which does occur through accidental leakogo has sometimes been insufficient, with the re- i suit that very severe losses have been gufltained owing to the occurrence of "brown heart" duo to excessive accumulation of carbon dioxide in the hold. The appearance of "brown heart" needs no special description. Its most distinguishing characters are firstly, that the brown tissue is killed and hence rapidly i loses water to the adjacent living tissues so that cavities are eventually formed. | For the same reason, when an apple is | cut across, the exposed surface dries up I much more rapidly in the region of the | affected tissue. The second characteristic 1 feature of this disease is that the external ! appearance of affected apples, except in t extreme cases, is perfectly normal. j Thirdly, when the casual conditions are I removed the disease does not spread. Lastly, it may be induced at any stage in the storage life, osd appears in its most characteristic form when it occurs early i before* the tissues of the apple have * softened and ripened. I In the past any kind of browning of the tissues of cold-stored apples has frequently been attributed by the trade to frost injury It is now evident that a variety of diseases occur in cold-stored apples which are not due to ■ freezing. Unfortunately, however, the after-effects of freezing are very variable 1 except in extreme case* when the whole of the flesh of the apples is brown, dead, and water-logged, and it is difficult to characterise them definitely. 1 ' -'.nil- j