December, 1920 



ceptible to scald than those receiving a 

 more moderate water supply and also 

 more susceptible than those that have 

 made a more even growth throughout 

 the season. In general large apples 

 scald earlier and more seriously than 

 small ones yet the question of size is 

 closely tied up with the orchard condi- 

 tions that produce the size and it is 

 often the forcing the apples have re- 

 ceived late in the season rather than 

 the largeness of the fruit that is really 

 responsible for the increased suscepti- 

 bility to scald. 



Another orchard condition that has 

 an influence upon the susceptibility of 

 the fruit to scald is the occurrence of 

 disease. Apples that have been rus- 

 setled by powdery mildew are more 

 susceptible to scald than those that are 

 free from it, but in general fruit from 

 diseased trees is more resistant to scald 

 than that from healthy ones. The most 

 striking example of increased resist- 

 ance to scald through the presence of 

 an orchard disease is found in the case 

 of cedar rust. York Imperial apples 

 from trees that have suffered from a 

 severe attack of cedar rust will re- 

 main free from scald four to eight 

 weeks longer than apples from similar 

 York Imperial trees that have been free 

 from the disease. 



The inherent susceptibility to scald 

 that the apple carries with it at pick- 

 ing time is then an extremely variable 

 characteristic dependent upon the 

 various orchard conditions that pre- 

 vailed throughout the season. A fail- 

 ure to give due consideration to the 

 quality of fruit at this time might re- 

 sult in blaming the cold storage man- 

 agement for the spoilage of apples that 

 really could hardly have been made to 

 keep or possibly in some cases to giv- 

 ing him credit for keeping fruit that 

 could hardly have been made to spoil. 

 But turning to the other side of the 

 question and taking the fruit as it comes 

 from the tree: What can still be done 

 to extend the storage life of the scald 

 susceptible varieties? In considering 

 this phase of the subject it should be 

 borne in mind that the apple as it goes 

 into storage is still a living organism 

 carrying on various complex life ac- 

 tivities. It is continually giving off 

 moisture and also odorous substances 

 and it is carrying on a respiration simi- 

 lar to that of man — taking up oxygen 

 and giving off carbon dioxide. These 

 life processes can not and should not 

 be stopped but the more slowly they 

 can be made to act the longer the apple 

 will live and the longer it will keep 

 it good qualities. The most satisfactory 

 and the almost universal method of 

 slowing down plant activities is to 

 lower the temperature and building on 

 this principle we have developed in 

 comparatively recent years our enor- 

 mous system of refrigerator cars and 

 cold storage plants. The apple has 

 '•'aimed its share of space in all this 

 development and as a result the apple 

 market and the apple season have been 

 greatly extended and the quality of the 

 fruit improved. But along with the de- 

 velopment of our modern storage 

 methods apple scald has come to the 



BETTER FRUIT 



front as one of our most serious apple 

 diseases. The apple rots appear to have 

 been with us always but apple scald is 

 essentially a modern disease. This 

 coincident development of the new dis- 

 ease and the modern storage has 

 naturally led many to suspect some 

 cause and effect relationship. Powell 

 and Fulton of the U. S. Department of 

 Agriculture investigated the question 

 some 17 years ago and reported that 

 they found no indication that cold 

 storage temperatures favored the de- 

 velopment of scald but rather that they 

 retarded it. The cold storage com- 

 panies have insisted that it was the 

 delay in reaching storage rather than 

 what happened in storage that was re- 

 sponsible for the trouble. But on the 

 other hand it has often been found 

 that apples stored in cellars or in air- 

 cooled plants have come out of stor- 

 age perhaps riper but with far less 

 scald than those held in commercial 

 cold storage. We decided to go over the 

 subject very carefully, covering a wide 

 range of temperatures so that we might 

 get not only the immediately practical 

 side but also the principle of scald de- 

 velopment. We carried on the work for 

 three consecutive years and included 

 practically all of the scald susceptible 

 commercial varieties in our tests. The 

 results were consistent throughout. 

 Varieties like Grimes scalded one to 

 four weeks earlier than York Imperial 

 or Black Twig, but in general apples 

 held at 60° or 70° scalded three or four 

 weeks earlier than those at 50°; those 

 at 50° four weeks earlier than those at 

 40°; those at 40° about three weeks ear- 

 lier than those at 32°, and those at 36° 

 also earlier than those at 32°. Between 

 60° and 32° each drop of 10 degrees 

 meant a delay of three to four weeks in 

 the time that scald would appear. The 

 higher temperatures tested are, of 

 course, out of the range of storage 

 practices but they are not higher than 

 those the apple is compelled to tolerate 

 in delayed storage. We have found 

 that a week to ten days delay in a 

 warm packing house or in an unrefrig- 

 erated car results in two to three times 

 as much scald on the delayed fruit as 

 on that stored immediately at 32° and 

 that the scald appears three to five 

 weeks earlier on the delayed fruit. 



The period immediately following the 

 removal of the fruit from the tree is 

 a lime when refrigeration is most 

 seriously needed and while 32° is the 

 most desirable temperature it should 

 not be overlooked that every degree 

 of cooling is valuable. 



One of the interesting things that de- 

 veloped in our temperature studies was 

 the fact that at temperatures above In 

 scald becomes evident as it is produced 

 hut that at 32° it does not. Apples held 

 constantly at 32° may be badly scalded 

 for months without showing any sign 

 of the trouble but given a day or two 

 in the warm air and they will go all 

 to pieces. The abnormal diseased con- 

 dition of the skin may develop at 32° 

 but the temperature is too low for the 

 •lenth anil spoilage processes to be com- 

 pleted. In the average commercial 

 storage plant where the doors are open 



Page 25 



almost every day the apples usually get 

 enough gusts of warm air to develop 

 evident traces of scald but in rooms 

 that are little disturbed the potentially 

 scalded apples show no sign of their 

 actually diseased condition. This pe- 

 culiarity of apple scald makes it a very 

 deceptive disease and one that is capa- 

 ble of causing serious misunderstand- 



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It costs money. For $20.00 you can 

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The Dencer Dryer will shorten time 

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It turns out a superior product. It 

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 capacity. 



I use only one stove for six tunnels. 

 Each tunnel holds 136 half bushel 

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My dryers have been a pronounced 

 success for four years. 



EDWARD DENCER 



R. 3, Box 158, Phone 88F2 

 SALEM, OREGON 



eERTISERS MENTION BETTER FRUIT 



