EFFECT OF 3,5,6-TRICHLORO-2-PYRIDYL-OXYACETIC ACID ON FRUIT SIZE AND YIELD OF CLAUSELLINA MANDARINE (CITRUS-UNSHIU MARC)

The application of 3,5,6-trichloro-2-pyrydil-oxyacetic acid increased fruit size of 'Clausellina' mandarin. The response was related to the size of fruit at the time of treatment. Two concentrations, 10 and 20 mg l-1, were tested with the same result on fruit size and fruit absci ssion. Because the increment in fruit size was irrespective of the num ber of fruits that remained on the tree, a direct effect of the auxin on fruit growth is suggested. This was confirmed by applying the auxin locally to a small number of fruits per tree. Fruit characteristics, with the exception of those related to fruit maturity, were not altere d by the treatments.