Also tested were a catching frame and a frame-mounted inertia shaker. The 

 frame had a conveyor and elevator to handle fruit in unusually large amounts. A 

 severe freeze halted this work in December 1962. Other work in Florida includes in- 

 strumentation of a shaker to measure removal forces and the screening of chemi- 

 cals to find an efficient fruit loosener. 



In California, AERD and State engineers are studying the physical properties 

 of citrus fruit in order to utilize these properties to achieve efficient mechanical har- 

 vesting of the fruit. Preliminary tests performed on navel oranges indicate (1) that 

 more than 75 percent of the oranges detached with a pull applied in line with the 

 stem were removed without stem or calyx, and (2) that oranges detached by spin- 

 ning separated with or without stem or calyx depending on the orientation of the 

 spin axis with the axis of the fruit core. Limited studies of citrtis trees and fruit 

 failed to reveal any electrical or thermal properties that could be utilized in me- 

 chanical harvesting. 



Drop tests in California are being evaluated. Additional work is planned in both 

 Florida and California. 



Other Approaches and Applications 



AERD, in collaboration with the Michigan and Washington Agricultural Experi- 

 ment Stations, is also planning research to improve equipment and methods for har- 

 vesting apples and pears from trees of different sizes and shapes and at different 

 planting distances — for example, tree walls and tree hedges of standard, semidwarf, 

 and dwarf trees; trees on trellises; and trees topped and in box shapes at different 

 distances apart. Where orchards with the desired tree size, shape, and spacing are 

 not available, trees will be grown for the study by the Michigan and Washington 

 State Experiment Stations. 



The University of California, Michigan State, and Cornell Universities are 

 working on machines to harvest and handle grapes. The California machines neces- 

 sitate training the vines so the grape clusters hang uniformly under holding wires. 

 The machine then clips the clusters with a moving knife and loads them into a 

 trailer. The Michigan State and Coraell machines are applications of the shaker 

 method of mechanical harvesting. 



The University of Florida has been working for many years on equipment to 

 pick oranges and grapefruit. One unit tested uses spindles to twist the fruit off the 

 tree. Although experimental, this unit appears to be promising. 



Others who have fruit harvesting projects either active or being planned are 

 Pennsylvania State University, Rutgers University, Oregon State University, Ohio 

 State University, and the University of Connecticut. Equipment manufacturers are 

 also conducting research. Any promising technique developed by these and other 

 experimenters will presumably find immediate application in the Nation's vineyards 

 and orchards. 



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