Influence of annual fruit shake-removal and Ethrel on citrus yield over four years

Trunk-shake harvesting did not reduce subsequent crops of orange cvs Washington and Leng Navel, Marsh grapefruit or Frost Nucellar Lisbon lemon when they were harvested about the middle of their maturity season, but it reduced subsequent yields of Valencia orange. Ethephon (as Ethrel) reduced the average annual yield of harvested fruit over the four years of the trial for all cultivars except Lisbon lemon. Thus, despite the risk of reducing subsequent cropping, trunk-shake harvesting without the use of Ethrel enables up to 80% of the crop to be removed with the remainder to be hand harvested according to market demand and price.