© 2003 Heron Publishing—Victoria, Canada
Fruit set dependence on carbohydrate availability in citrus trees
Domingo J. Iglesias (1), Francisco R. Tadeo (1), Eduardo Primo-Millo (1) and Manuel Talon (1, 2)
1. Departamento de Citricultura y Otros Frutales, Instituto Valenciano de Investigaciones Agrarias, Apartado Oficial, E-46113
Moncada, Valencia, Spain / 2. Author to whom correspondence should be addressed (mtalon@ivia.es) / Received May 31, 2002; accepted July 30, 2002; published online January 31, 2003
Summary
We generated source–sink imbalances by defoliation and sucrose supplementation by stem injection, to investigate effects of
carbohydrate availability on fruitlet growth and abscission in cv. Okitsu of Satsuma mandarins (Citrus unshiu (Mak.) Marc.). Partial defoliation promoted fruitlet abscission, whereas sucrose supplementation increased citrus fruit set
by more than 10%. Moreover, when applied together, sucrose supplementation counteracted the effect of partial defoliation
on fruit set. When sucrose was supplied continuously from flowering until harvest, it increased the concentrations of soluble
and insoluble sugars in fruits. We conclude that fruit set in citrus is highly dependent on carbohydrate availability.
Keywords:
carbon availability, defoliation, fruit abscission, source–sink imbalances, sucrose supplementation.
