APPLE COLLAPSE.

Hauraki Plains Gazette, Volume XXXV, Issue 4706, 2 June 1924, Page 4

APPLE COLLAPSE.

COOL STORAGE PROBLEM, EXPERIMENTS BY DEPARTMENT. Some rcmarkaDie races concerned with the cool storage of apples were related in an interview with Mr R. Waters, officer in charge of the Biological Laboratory, Wellington, who, inccinpany with Mr W. C. Hyde, of the Horticultural Division, is engaged in experimenting to ascertain the cause of apple flesh collapse in cool stores. In the course of these experiments he has been obliged to embark upon a line of investigation which now indicated that there was a big factor in cool storage that had hitherto received little* or no consideration. It seemed to him that .whilst it was necessary to know the temperature in a store us indicated by a thermometer; the humidity as shown by an hygrometer; and to provide circulation and ventilation, accoring to the best experience, yet it might be even more valuable if one could estimate the effects of these four storage factors from periodical observations of the actual condition of the fiuit itself. In short, his idea was to try to make the apple itself the- indicator as to whether the store was being properlytreated. He accordingly .started out on what he calls his “Loss-in-weight” experiments. Eighteen cases of Stunner,s were taken, each containing exactly 401 b of freshly-picked fruit. Six of these were placed in a low temperature (34) ; six in a medium temperature (37) ; and six in a high temperature (i.e., at ordinary atmospheric temperature in a packing shed). The fruit in these eighteen cases was reweighed at intervals to ascertain how much each 401 b of fruit had lost in

weight through the exhalation pf water vapour and gases. The following are some of the results obtained. 1. -4O'.b of Stunners can lose over lib (equal to 2 J /a per cent.)' without any change ill their outward appearance. :1. 40lb of Stunners can lose 21b in weight (5 per cent.) without any damage resulting from a commercial point of view. 3. When 401 b of Stunners had lost 3lb in weight (7% per cent.) slight shrivelling resulted. 4. When 401 b had lost 4lb (10 per cent.) they were damaged commercially. 5. The loss in weight was grealet and Quicker in the higher than in the lower temperatures. “hi order to realise the tearing of these figures upon practical cool storagc.’’ he said, “let us assume for the moment that we have a cool chamber containing 5000 cases, and that it is necessary to extract 11b of water from each case (401 b in the first four weeks of storage. This would mean the removal of 50001 b of water, which is equal to 500 gallons, in four weeks. ’ The amount of water extracted by different stores in past years had varied greatly, he continued ; in fact, this was a matter in which the practice of some stores differed most from that of others. No doubt there were a number of reasons to which this was due. For instance, there was no standard to follow ; again, the equipment that effected the drying power of stores varied considerably in its capacity; then the management o* 1 such equipment varied according to the ideas of the engineer in charge ; finally, there was no satisfactory means of estimating what the equipment or its management was actually accomplishing in this direction. It seemed that where such largo quantities of water, etc., were involv- | ed. it was essential that cue should

know exactly what amount was the ■ best to extract and have the means vf telling whether this was being accomplished week by week. The hygrometer registered the humidity, but the loss in weight could be estimated pcr’odically by reweighing from time to time a definite weight ot fruit, as was done in his experiments. For ex- ... perimental purposes he had drawn up a schedule showing how much loss in weight he required each week during ■ the whole storage season. This schedule had taxed very heavily the drying resources of the cool stores in the first few weeks pf storage. The use z of wet cases had added to their diffi- , culties. He had some 7000 cases un-. . der experimental conditions, and was aiming to extract from the fruit such amount as was possible without, at the end of the storage season, showing any signs of shrivel. This experiment would no doubt show whether apples so treated will have greater resistance to flesh collapse. Some of the fruit had now been in store over two months and so far appeared to be in a satisfactory condition.