Vol. 116 (2003): Proceedings of the Florida State Horticultural Society
Citrus

Trunk shaker and abscission chemical effects on yields, fruit removal, and growth of orange trees

Jodie D. Whitney
University of Florida

Published 2003-12-01

Keywords

  • 5-chloro-3-methyl-4-nitro-1h-pyrazole,
  • mechanical harvesting,
  • metsulfuron-methyl,
  • prosulfuron,
  • trunk growth

Abstract

In a 5-year study, available abscission chemicals were applied to 'Hamlin', 'Pineapple', and 'Valencia' orange trees, which were harvested with commercially available trunk shakers. In the first 2 years, abscission chemicals prosulfuron and metsulfuron- methyl were applied and loosened mature fruit, but were phytotoxic to the trees and young 'Valencia' fruit. Abscission chemical CMN-P (5-chloro-3-methyl-4-nitro-1H-pyrazole) was applied the last 3 years and it provided better loosening of mature fruit without being phytotoxic to the trees, young 'Valencia' fruit, or reducing yields. Trunk circumference growth was not affected by shaker and/or abscission chemicals. CMNP increased total fruit removal of the trunk shaker an average of 9%. Trunk shakers did not significantly reduce total yields compared to conventional manual harvesting methods.