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.^ 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 im- 

 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. Tn U. S. Dept. Agr., Bur. 

 Soils, Field Operations, 1908, 10th Rpt, pp. 1331-1372, fig. 37. 1911. 



3 Stubenrauch, A. V. Fruit handling, precooling, and storage investigations. In Ice 

 and Refrigeration, v. 42, No. 1, pp. 34-86, 1912. 



