But the significant savings made by mechanically harvesting apples instead of 

 handpicking them are now more or less offset by increased processing costs because 

 of bruising and other factors. The aim of present research is to reduce these in- 

 creased costs — for example, from a possible $7.05 a ton to less than $1.00 per ton. 



Apples for the fresh-fruit market are mostly handpicked — again because ma- 

 chine picking causes too much bruising and the consumer won't buy excessively 

 bruised apples. 



Peaches, Pears, and Apricots 



Engineers at the California Agricultural Experiment Station studied the feasi- 

 bility of shaking peaches and Bartlett pears onto a catching frame. More than 75 

 percent of the peaches and an average 68 percent of the pears were free from 

 visible defects. The fall through the trees damaged more fruit than the falling 

 onto and over the catching frame. The taller the tree, the more fruit was injured. 



AERD attained a degree of selectivity (harvesting only mature fruit) in har- 

 vesting apricots by using an inertia shaker. Frequencies of 250 to 400 cycles per 

 minute and a stroke of 1-3/4 inches at the limbs gave the best results. Similarly 

 harvesting peaches gave only limited selectivity and AERD concluded that such 

 a method of harvesting would not be satisfactory for commercial operations. These 

 studies further showed that the use of decelerator strips and proper padding is 

 mandatory to reduce fruit injury. 



Grapes 



In 1962, six States in the United States produced 286,250 tons of Concord 

 grapes, which were mostly picked by hand and handled in boxes, lugs, and trays 

 that hold from 32 to 42 pounds each. Thus, about 15 million containers had to 

 be picked up by hand and moved out of vineyards on trailers or wagons. Grapes 

 are harvested late in the season and it is difficult to find workers to do the harvest- 

 ing. 



The efforts of AERD's engineers to relieve this situation began in 1958.^ They 

 initially found that very little experimental work had been done to improve the har- 

 vesting and orchard handling of Concord grapes. They also found that overfilling 

 the lugs, and other accepted harvesting and handling practices, accelerated quality 

 deterioration. Other AERD findings are summarized below: 



Mechanical Harvesting 



AERD engineers experimentally harvested two 14-vine rows of Concord grapes 

 using the same equipment used to harvest blueberries mechanically. They harvested 

 at the rate of 318 pounds per man-hour — about twice the rate of handpickers. But 

 the vibrators cracked between 45 and 50 percent of the grapes during separation; no 

 damage resulted when the grapes fell on the collecting fame. 



Shaker equipment can be designed to harvest muscadine grapes when the acre- 

 age warrants. 



^ See ARS 42-42, "A Progress Report on Harvesting and Handling Concord Grapes," available 

 from the Agricultural Engineering Research Division, ARS, U.S. Department of Agriculture, Plant 

 Industry Station, Beltsville, Md. 20705 



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