STORAGE OF CALIFORNIA TABLE GRAPES. 5 



marketed in splint baskets inclosed in slatted crates. The full or 

 u double'' crates formerly contained eight 5-pound baskets, but these 

 are now used only to a slight extent. The smaller crates in common 

 use, sometimes designated as half crates, contain four 5-pound baskets 

 or two 10-pound baskets, packed high to make a full net weight of 

 24 to 20 pounds of fruit. Although no filler had been used in pack- 

 ing grapes for commercial shipments before the Bureau work was 

 begun, systematic investigation soon showed the use of the ordinary 

 commercial crate without a filler to be unsuitable for packing grapes 

 intended for long-time storage. Tight boxes holding about 10 

 pounds of fruit were used in the first experiments, some of the grapes 

 being packed with a filler and some without a filler. The tight pack- 

 ages without a filler proved to be as unsuitable for long storage as 

 were the slatted crates. When a filler was employed, however, the 

 period during which the grapes could be held in good condition was 

 considerably lengthened, and for long storage a filler was found to be 

 absolutely necessary. 



When the search for a suitable material was begun by the Bureau, 

 workers the standard of comparison first used was cork dust, or 

 ground cork, similar to that in which the Spanish grapes are packed. 

 (PL I, fig. 2.) It was soon realized, however, that it would be prac- 

 tically impossible to obtain large quantities of cork on the Pacific 

 coast at a price sufficiently low to make possible its commercial use, 

 and the Department work therefore included the study of a number 

 of possible substitutes. As there were no precedents to guide these 

 early investigations, every possible filling material was thoroughly 

 tested, including corn pith, shredded paper, wheat bran, corn meal, 

 coconut pollen, ground and shredded tule, and redwood sawdust. 

 It is unnecessary to describe in detail the results of these tests, since 

 all except the redwood sawdust proved unsatisfactory for one reason 

 or another. Fortunately for the California table-grape industry 

 if this system of handling assumes large commercial importance, the 

 redwood sawdust from the start proved even superior to the ground 

 cork. The grapes- were found to keep longer and in better condition 

 under the same storage conditions when packed with a filler of red- 

 wood sawdust than with any other material. This surprising success 

 was at first questioned, but repeated investigations during the past 

 seven seasons have fully corroborated the results of the early work. 



The reason for the better holding quality of redwood sawdust is 

 not fully understood. In the first experiments the sawdust from 

 planing mills was used (PL II, fig. 1), and as this was composed 

 almost entirely of very minute particles its superior holding quality 

 was thought to be due to the fineness of the material. A comparison 

 of cork ground to the same degree of fineness showed, however, that 



