- 23 - 



BRUISING 



The first bruising studies of apples in pallet boxes in Washington were 

 made in 1950 by the Washington State Apple Commission. In 1955, the Agricul- 

 tural Research Service began more detailed studies on bruising at the Tree 

 Fruit Experiment Station at Wenatchee. These studies were expanded during 

 the 1956 harvest season and again in 1957. They were supplemented by the 

 research of the Agricultural Marketing Service in 1957. 



Early Studies 



In 1956, the Agricultural Research Service made studies with bruise-free 

 fruit placed carefully in a deep pallet box and found that the bruising was 

 directly proportional to the depth of the boxes. However, it was determined 

 that the average amount of bruising in a 38-inch deep pallet box was almost 

 identical to that when the standard apple box was used,, In 1957, more exten- 

 sive studies were made during harvest of 2,000 standard box equivalents of 

 apples in pallet boxes of 23 to 27 loose field or standard box capacity. 

 Bruising from picking, hauling, storing and emptying the pallet boxes onto a 

 commercial packing line was included. All flattened areas were considered as 

 bruises whether discolored or not. 



Results 



Bruising or marking occurring on Golden Delicious apples harvested in 

 pallet boxes were associated with the various stages as follows: 



Percent 



Picking 32 



Hauling 1 



Storage . 31 



Emptying 36 



Comparisons made between 32- and 30-inch high pallet boxes showed no difference 

 in bruising. 



Hauling consisted of moving pallet boxes out of the orchard with a 

 tractor-mounted, high-lift fork, decking them 2 high, hauling to the loading 

 area, loading on a highway truck and hauling 2 to 3 miles to the storage plant. 

 Cold storage bruises were attributed to the weight of apples resting on each 

 other in pallet boxes for a period of 9 weeks. The pallet boxes were emptied 

 with an inverting-type commercial box dumper (fig. 13). 



Apples handled in pallet-box were compared with handling of standard 

 boxes which were placed on pallets after being filled in the orchard and then 

 hauled to cold storage. The boxed apples were stored as long as those in 

 pallet boxes and were emptied onto a commercial packing line with a stack- 

 breaking type automatic box dumper. 



