Preliminary shaking tests in 1970 for citrus harvesting in Ventura County did not produce the desired percentage of fruit removal without damage to fruit or foliage. There was excessive damage to mature navel oranges during removal, and also damage to small green Valencia oranges, grapefruit, and lemons that would have matured into the next season's crop. However, separation of mature fruit from the stem was acceptable for all varieties. Further equipment modifications and abscission chemicals will be necessary to provide efficient harvesting of more mature, good quality fruit with less damage to the immature fruit that should remain on the tree. Research is continuing with growth regulators to find a successful abscission-producing material that would loosen the mature fruit…with minimum peel damage…as an aid to shake-harvesting. Successful commercial abscission trials using cycloheximide on oranges have recently been reported in Florida.

Richard and Terry Brandt, Orchard Machinery Corp., Yuba City; Elvin Barnhart, Limoneira Co., Santa Paula; Edwin Burger, Camulos Ranch, Piru; Paul Leavens, Ventura; Donald Noel, Barsdale; and Kenneth Glenn, Rancho Sespe, Fillmore.