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2 BULLETIN 1104, U. S. DEPARTMENT OF AGRICULTURE. 
This browning of the interior of the fruit had been up to this 
time frequently confused with frost injury, due to low temperature 
of the storage rooms, with the result that claims for damages had 
been made and allowed. In Powell’s storage experiments the 
records showed that the temperature of the fruit had not been below 
freezing at any time. The storage work was continued in 1906 and 
1907 with similar results. The Red Pearmain (probably Pomme de 
Fer), White Pearmain, Yellow Bellflower, Missouri, and Yellow 
Newtown varieties from the Pajaro Valley were all more or less af- 
fected with this tissue browning, while apples from other localities 
in California stored under precisely the same conditions were sound. 
In the hope of determining the cause of this trouble and working 
out some method of preventing it, an investigation was begun by | 
Powell and his associates. In this work various experiments were 
conducted on the relation of character of the soil, of delayed storage, 
and of the state of maturity at which the fruit was picked to the 
prevalence of this browning in the stored fruit. 
At the request of the Bureau of Plant Industry a soil survey of 
the Pajaro Valley was made by Mackie, of the Bureau of Soils, 
United States Department of Agriculture.2 No definite results as 
to the cause of the disease or methods for its control were obtained 
by Powell. The accumulated evidence was mostly negative in char- 
acter and as such, of course, of value in the continued investigation 
of the trouble. Inasmuch as Powell did not publish his results and 
the work of Mackie dealt entirely with the soil survey, there is no 
account of these earlier investigations in the literature. In 1912, 
however, Stubenrauch, who worked with Powell in the early part of 
the investigation and was later in charge of the work, reported on 
the effect of different storage temperatures on the occurrence of 
browning.’ . 
In experiments started in 1909 covering two years Yellow New- 
town apples from various portions of the Pajaro Valley were stored 
at different temperatures and inspected several times during the 
storage season. The method of inspection was to remove boxes of 
fruit from each lot, cutting half the apples in each box crosswise 1m- 
mediately upon withdrawal. The rest of the box was allowed to 
remain at common market temperatures for 10 days and was then 
cut and inspected. A large quantity of fruit, some 300 or 400 boxes, 
cut and inspected during these two years, furnished a means of deter- 
mining rather accurately the extent of browning and its progress dur- 
2 Mackie, W. W. Soil survey of the Pajaro Valley, Calif. Jn U. S. Dept. Agr., Bur. 
Soils, Field Operations, 1908, 10th Rpt., pp. 1331-13872, fig. 37. 1911. 
3Stubenrauch, A. V. Fruit handling, precooling, and storage investigations. Jn Ice 
and Refrigeration, vy. 42, No. 1, pp. 34-86, 1912, 
