PRODUCTION OF 'PONKAN' MANDARIN UNDER BIANUAL CHEMICAL THINNING

The use of management practices, which provide the development of larger fruits and flowering the following year, is essential to ensure the high productivity of 'Ponkan' mandarin (Citrus reticulata Blanco). For this reason, this study was carried out to evaluate the influence of chemical thinning with Ethephon applied for two years, on the production regularity of 'Ponkan' mandarin. Five concentrations of Ethephon: 0, 200, 400, 600 and 800 mg L-1, were tested, applied after the period of physiological fruit drop, in January 2009 and January 2010, when they were 25 to 30 mm in the transverse diameter. The experimental design was randomized blocks with four replications and four plants per plot. There was influence of Ethephon concentrations in the percentage of thinning, production, alternate bearing, mass and diameter of fruits. The concentration of 600 mg L-1 Ethephon applied two consecutive years was the most suitable to regulate the 'Ponkan' mandarin production.