Intensities and times of manual thinning of 'montenegrina' tangerine

Abstract

Seven-year-old trees of 'Montenegrina' tangerines (Citrus deliciosa Tenore) budded on Poncirus trifoliata Raf. of a commercial orchard situated in Viamão, RS, Southern Brazil, which presented a high level of biennial bearing, were submitted to three regimes of manual thinning as follows: control (without thinning), manual thinning of 2/3 or 66.6% of the young fruits, and manual thinning of 5/6 or 83.3% of the young fruits. The above treatments were applied in January, February, and March, corresponding to 60, 90 and 120 days after the end of fruit drop. Results of the two first crops after thinning showed that independent by of time, the manual thinning of 66.6% and 83.3% of young fruits increased fruit quality in the year of thinning and break biennial bearing in the year after.