APPLE SHIPMENTS

Nelson Evening Mail, Volume LVI, 2 December 1922, Page 7

APPLE SHIPMENTS

PREVENTABLE LOSS TEMPERATURE AND VENTILA- , TION Sonic plain speaking,with, reference to the preventable loss and waste incurred in the shipment of apples overseas, indulged in by Professor McAlpine, Commonwealth Investigator of Fruit Diseases, in a special report on the subject, which is of particular interest to fruitgrowers in New Zealand, on account of its methods of dealing with brownheart, which is causing them anxiety just now. Professor McAlpine’s researches have won" wide recognition; his five volumes on fruit diseases have become the world’s text-books in the industry. “First and last,” he says, “the trouble is caused in the ship ’.if cold storage chambers. With a uniform temperature of 30-32 deg. Fahr., and with sufficient ventilation, fruit, will arrive in England in the same condition, in which it loaves Australia or New Zealand. There is a ventilating system in the tissues of the apple, and, when deprived of air, the carbon dioxide will lake its place and act injuriously. Owing to the neglect of this precaution to provide a free circulation of air, the browning and damage of the tissue around the core was the result, • In other words, brownheart is caused ' by the lack of oxygen and the excess of*carbon dioxide in the hold where the fruit is stored. If proper ventilation is provided there will be no brownheart, and, if fluctuations of temperature are avoided, there will, be no bitter pit in apples.”

UNIFORM TEMPERATURE NEEDED , While brownheart has lieen so general during the past fruit season, all the shipments were not so affected, says the Professor. This points to.the possibility of being able to overcome it. The first and most important point to attend to in thp carriage of apples overseas is that of temperature. It is a well-established fact that if apples are stored at 30,-32 deg., and if fluctuations are prevented* there is no development of bitter pit during a period sufficiently Jong to transport the fruit to Europe. lie has tested this temperature wjth satisfactory results, and keeping the temperature, within such narrow limits is thoroughly practicable. A cpmmon misunderstanding exists relating to the danger '- to freezing. Whenever a temperature •of 52 is mentioned it is ruled out of 'court at once, because it freezing point. But that is the freezing point of water, and it does not .seem to bo generally known that the freezing point of water is several degrees Below thatNot only is browning prevented at this temperature, but also the ripening" pro;- , cess is arrested. There .is' a slowing down of vital activity, and it is practically a case of suspended animation/ He- ' ports that apples arrive' overripe m London are a sure indication that the temperature has not been maintained, if the fruit was shipped in proper ’ condition.

PROBLEM Almost of equal importance is ventilation. In the case of successful shipments, such as that by the Somerset, inspected into the hold by Professor Me Alpine, slats were placed between each case, so that, a current of air circulated freely around them. Since the question of ventilation is essentially an engineering problem, the continuous .introduction of fresh air into the hold where the apples arc stored will no doubt be satisfactorily settled from the experience gained during the past season. A third point is that of the condition of the apples. Bv measuring growing apples with a pair of calipers the Professor says he has proved, that they reach a stage when growth ceases, and then begin to ripen. When the apple is full grown .and just beginning to ripen, that is the proper stage to pick fruit for the Home market. This stage is roughly indicated by the orchardist, when he speaks of picking the apples for export on the “greon”sidc. . In his experiments with overseas shipments ho did not. he says, consider it necessary to test the question of pre-cooling, - for Hie simple reason that when the fruit was sent from country, centres in Louvre in trucks to the ship's side, and when the temperature was gradually reduced to 32deg., the results were quite satisfactory, without any further prellm'ii, ary pi coautions.