The aim of this research was to evaluate the ethephon effect on chemical thinning of the mandarin fruits 'Ponkan'. The ethephon was applied in the plants of mandarin in two development stages of the fruits: one and two cm of diameter, being tested four concentrations, 0,0; 100; 200 and 400mg L-1. Three experimental units with four repetitions were used, in a total of 96 plants. The quality of the fruits was evaluated with the characteristics of average weight of the fruit, transversal and longitudinal diameter of the fruit, corners and seed numbers, soluble solids (°Brix); pH of the juice, titratable acidity, ratio between °Brix and acidity (ratio) and production. The ethephon application for the chemical thinning of the mandarin 'Ponkan' at 400mg L-1 concentration in the development stage of two cm provide the best result with increase in weight of the fruits when compared to the non-chemical application.
Citrus reticulata; chemical thinning; ethylene; 2-chloroethylphosphonic acid
