20 CIRCULAR NO. 1U, BUREAU OF PLANT INDUSTRY. 



transit of the maturity of the fruit at the time of picking, immediate 

 and delayed cooling and storage, and methods of handling in the 

 orchards and packing houses. Up to last season little had been done, 

 at least in a systematic way, with the precooling and storage of Bart- 

 lett pears in the valley. Usually the fruit is shipped out as soon as 

 possible after picking and packing, although it is often delayed two 

 to four days and sometimes longer, either loose or packed, in the 

 packing houses before it is loaded into refrigerator cars. After 

 arrival in the eastern markets, fruit handled in this way must be 

 sold immediately or else placed in cold storage. Most of the attempts 

 to store Bartletts in the East after shipment across the continent 

 have not been very successful or encouraging. Too much time 

 elapses between picking and storing, and the fruit is often exposed 

 to high and variable temperatures while in transit. 



DESCRIPTION OP THE EXPERIMENTS. 



Pickings were made from three different orchards in sections rep- 

 resenting three different types of soil. Four pickings were made 

 from each orchard at intervals of a week, the first just before the 

 regular commercial pickings were started and the last fully a week 

 after the usual Bartlett season had come to an end. Thirty-two 

 boxes of fruit were picked at each picking from each orchard, mak- 

 ing 384 boxes in all. 



In order to test the effect of precooling before and after packing, 

 half of each pick (16 boxes) was packed as soon as possible after 

 picking and the other half was held loose in the "lug" or picking 

 boxes. Half of each packed and loose lot was placed in the cooling 

 room immediately after picking or packing, while the other half 

 was held for two days before cooling. In the discussion which fol- 

 lows the former are referred to as " immediately cooled " and the 

 latter as " delayed." 



The precooling and storage tests were made in three rooms rented 

 from the Medford Tee and Storage Co.. one room being used for 

 precooling, one for packing, and the other for storage. 



The fruit was picked by regular pickers under the supervision of 

 representatives of the Bureau of Plant Industry. Some of the fruit 

 was packed by regular packers, but most of this work was done by 

 the Bureau men. When the pears were placed in the precooling room 

 the temperature of the room was usually about 20° F., but it increased 

 slightly after the warm fruit was put in. Actual fruit temperatures 

 were taken before placing the pears in the precooling room and 

 during the cooling by means of thermometers inserted into fruits, 

 both near the center and toward the outside of the package. When 

 the temperature of the outer fruit in the packed boxes and the loose 

 fruit in the lug boxes approached 32° the room temperature was 



[Cir. 114] 



