38 EXPEKIMENT STATION RECORD. [Vol. 43 



monthly during,' 1919, and the distribution ot the exports by principal countries 

 durins November and December and for the calendar year 1919. 



It is noted that during the tive fiscal years, 191^^-1918, the United Kingdom 

 took CrO per cent of the quantity and 59 i>er cent of the value of the total ex- 

 ports of fresh apples from this country. Next to the United Kingdom, Canada, 

 Argentina, Brazil, and Australia were the best markets during the war for 

 American fresh apples. A brief history of the export prices from 1791 to 

 January, 1920, is given ; imports of green and dried apples for the first three- 

 quart(>rs of 1919 are shown; and the domestic production, the leading apple- 

 producing sections, and the varieties produced in different regions are described. 



Cold storage for Iowa apples.— A, Control of certain diseases of cold- 

 stored apples; B, Changes of tenii)erature in cold-stored apples, W. E. 

 AVhitiohouse {loira Sta. Bui. 192 {WIU), pp. ll'.)-216, figs. U).—A report of 

 progress made in the station's long-continued apple-storage investigations (E. 

 S. R., 30, p. 41). The first part of the report contains the results of investiga- 

 tions and observations relative to the development and control of apple scald 

 and certain apple rots. The second part discusses changes in temperature of 

 cold-stored apples, as affected by different methods of packing the fruit. A 

 bibliography of related literature is given, and the station's cold-storage plant 

 is described. 



Summing up the results of his study, the author concludes that temperature 

 is a very important factor in the control of apple scald and of other more com- 

 mon diseases of apples in cold storage. A constant storage temperature not 

 higher than 32° F. has given the best conti-ol of these diseases. It is con- 

 cluded, however, that the losses in storage from apple rots may be practically 

 eliminated by proper spraying, harvesting, handling, grading, and packing the 

 fruit, keeping it at a constant low temperature and removing it from storage 

 before the storage season for the particular variety in question closes. No 

 correlation was found between the size of the apples and the amount of scald 

 developing on them in storage, but the largest apples were generally attacked 

 more quickly by rots in storage than smaller apples of the same variety, other 

 things being equal. Apple scald makes fruit more susceptible to the entrance 

 of rot fungi. Alternaria rot, which is a black fungais growth, develops readily 

 on the badly scalded iwrtions of the fruit and hastens decay. The author has 

 had under observation an unidentified dry brown rot, which appeared on both 

 Jonathan and Northwestern Greening apples, developing sunken areas in which 

 the skin becomes a clear-brown color, varying from a medium to a rather 

 light tone and remains unbroken. The flesh beneath becomes dry and brown, 

 or brownish, to a depth of 0.125 to 0.25 in. All attempts to isolate a causal 

 parasitic or saprophytic organism from the affected tissue have thus far failed. 

 Humidity was found to bear some relation to the development of apple scald, 

 but was less important than temperature. Less scald developed in n relative 

 humidity of from CO to 70 per cent than in one of from SO to 90 per cent. Wrap- 

 ping apples in paper delayed the appearance of scald during storage. Paraffined 

 paper retarded scald more than ordinary wrapping paper, but the difference 

 was too slight to be of commercial importance. Immature fruit scalded readily 

 in storage. Whatever the variety of apples under consideration it is in the 

 best, condition for cold storage when it is well colored and hard ripe. If the 

 fruit must be picked early to avoid freezes it may be held at ordinary tempera- 

 tures until it more nearly reaches the best degree of maturity for cold storing. 

 Apples in prime maturity for cold storing will scald more quickly in conunon 

 than in cold storage. Iowa-grown Mammoth Black Twig and Sheriff apples 

 can be stored with only fair success in common storage houses, and should be 

 allowed to get as much red color as possible before packing. 



