rage 12 



little worse with 80, 90 and 95 per cent 

 relative humidity than with 50 per cent. 

 On the other hand if the air was kept 

 in gentle motion scald did not occur 

 even with the highest humidities. Some 

 indication was found that moistures de- 

 posited in drops on the apple might 

 favor the development of a sort of 

 spotted scald but on the whole the ex- 

 periments showed that humidity played 

 little if any part in the production of 

 scald as it occurs in commercial stor- 

 age. 



Defeated in our purpose of proving 

 the humidity guilty, we felt sure that 

 the trouble must be due to abnormal 

 respiration conditions, either that the 

 oxygen of the air boxes became too 

 greatly reduced or the carbon dioxid 

 accumulated to a harmful extent. Ex- 

 periments were made in holding apples 

 in atmosphere having various percent- 

 ages of oxygen, the normal amount, an 

 excess and a deficiency, but they scald- 

 ed alike under all the conditions. Tests 

 were made with carbon dioxide, the ap- 

 ples being stored in atmospheres having 

 various percentages of the gas, some of 

 them much higher than ever occur in 

 commercial storage; but we found that 

 carbon dioxide really tended to delay 

 rather than hasten the development of 

 scald. We were especially disappointed 

 with the outcome of the tests on car- 

 bon dioxide for we knew that the gas 

 sometimes becomes quite strong in stor- 

 age rooms and we felt sure it would 

 be found an important factor in scald 

 production. 



We did, however, obtain one impor- 

 tant result in connection with the ex- 

 periments on carbon dioxide and mois- 

 ture. While the results showed that 

 these substances were not responsible 

 for the occurrence of scald they proved 

 that they were the cause of what is 

 known as soft scald. Soft scald oc- 

 curs largely on Jonathan and Rome 

 Beauty apples and occasionally on 

 Spitzenberg and Stayman Wincsap. It 

 produces blister like areas on the skin 

 that extend over the surface, in various 

 peculiar patterns. The red surfaces are 

 attacked as much as the green ones and 

 there is a clear cut margin between 

 the sound and diseased tissue. It bears 

 some resemblance to frost injury and 

 damages have sometimes been paid on 

 it under that name. The cause of the 

 disease, however, is not too low a tem- 

 perature but an excessive accumulation 

 of carbon dioxide and moisture usually 

 at a high temperature and especially 

 in cases of delayed storage. In all the 

 cases of soft scald of which we have 

 been able lo obtain the records, the 

 fruit had been delayed at a fairly high 

 temperature before going into storage. 



To return to the apple scald question 

 we found ourselves near the end of 

 the third year of our storage experi- 

 ments with little but negative evidence 

 as to the substance that was really 

 causing the scald. We had made no 

 experiments on the odor producing and 

 related substances given off by the ap- 

 ple. We didn't know what they were 

 nor what would absorb them and really 

 didn't think they could be of impor- 

 tance. But following up the gas mask 



BETTER FRUIT 



idea we stored apples in various kinds 

 of charcoal and sawdust and in almost 

 everything we could think of that had 

 some gas absorbing power. We knew 

 that butter absorbed odors and that 

 fats and oils were used in extracting 

 perfumery so we made a thorough test 

 with wrappers impregnated with vari- 

 ous waxes, fats and oils. Most of the 

 things tested were a failure, the wax 

 and paraffin wrappers were of little 

 value but those with either a fat or an 

 oil were a complete success. We have 

 used the oiled wrappers now for three 

 years, have tried them on practically 

 every scald susceptible variety and 

 tested them under the most severe and 

 unfavorable storage conditions and 

 with the exception of one test they have 

 always given 100 per cent control of 

 scald. The exception was with a very 

 gi°en lot of Black Twigs and in this 

 case the disease was delayed about a 

 month and was reduced from 65 per 

 cent on the unwrapped to 15 per cent 

 on the oil-wrapped fruit. We have 

 tested almost all kinds of vegetable, an- 

 imal and mineral oils and while most 

 of them will control the scald the highly 

 refined paraffin oils seem to be the most 

 satisfactory. They are among the 

 cheapest oils, they do not become 

 rancid, and they are already extensively 

 used on paper and otherwise in connec- 

 tion with food products. 



The oiled wrapper is by far the most 

 efficient remedy we have found for 

 scald. It also has an advantage over 

 other devices for scald prevention in 

 the fact that it is always with the fruit 

 furnishing protection on the way to 

 storage, while in storage and in after 

 storage shipments. 



One difficulty with the oiled wrapper 

 is that it is not adapted for use with 

 barreled apples and these need protec- 

 tion from scald more than any others. 

 We have tried to find some other means 



January, 192 1 



than the wrapper of carrying the oil 

 with the apple. We have experimented 

 with oiled barrels and with scraps and 

 strips of oiled blotter scattered through 

 the barrel, but the oil does not come in 

 close enough contact with the bulk of 

 the fruit to give anything like complete 

 scald control. We have tried spraying 

 the oil on the fruit as it goes over the 

 packing table. This prevented scald but 

 produced a scald-like injury where the 

 oil remained in drops on the skin. 

 Wiping the apples with an oiled rag 

 has so far given complete scald control 

 without injury but we have tried this 

 only one season and on but a few va- 

 rieties of apples. The method will be 

 given a very thorough test the coming 

 year. If it should prove an entire suc- 

 cess there are already fruit wiping 

 grader attachments on the market that 

 could probably be utilized for applying 

 the oil mechanically. 



It may take several years of general 

 commercial use to determine the most 

 satisfactory manner of handling the 

 scald problem but the disease is a pre- 

 ventable one and we have several meth- 

 ods of attack. Whatever is done, 

 whether in the way of oiled apples, 

 oiled wrappers, ventilated barrels, or 

 ventilated cars, packing houses and 

 storage rooms would have the same ob- 

 ject; that of removing from the apples 

 the harmful gases of their own pro- 

 duction. 



There will be more demand for trees, 

 shrubs and vines than can be supplied 

 by reliable nurserymen. Those who are 

 intending to put out ornamental, shade 

 or fruit trees, shrubs or vines should 

 get in communication with growers of 

 known reliability and place their orders 

 early. 



Ridley,Houlding&Co. 



COVENT GARDEN, LONDON 

 WE ARE 



Specialists in 

 Apples and Pears 



CABLE ADDRESS: BOTANIZING, LONDON 



Codes: A. B. C. 5th Edition and Modem Economy 



HEN WRITING ADVE 



BETTER FRUI 



