VEGETATIVE GROWTH, YIELD AND FRUIT QUALITY OF 'GALA' APPLE TREATED WITH REGALIS (PROHEXADIONE-CA)

The trial was conducted in a ‘Gala’/M.9 orchard and the experiment was designed as a randomized block comprising four treatments (application of prohexadione-Ca: 125 mg^-l, 250 mg^-l, 2×125 mg^-l, and control - without growth regulator). Experiments have been carried out for 2 years (2003, 2004). Application of Regalis® reduced trunk cross-sectional area increment, and cumulative extension shoot growth. The effect increased with increasing concentration, and a greater inhibition was obtained when the trees were sprayed two times. Compared to control, return bloom of Regalis®-treated trees was not affected. No negative effects of treatment with Regalis® on yield per tree were observed, but some reduction of average fruit weight was found.