M.C. Dussi, G. Gharding, P. Reeb, F. De Bernardin, E. Apendino
A trial was conducted for studying different thinning programs in apple cv. ‘Royal Gala’. The following treatments were applied in a completely randomized design: -1: NAA 10 mgL-1 at 5mm fruit diameter (FD) + 6Benzyladenine (6BA) 50 mgL-1 at 8 mm FD; -2: NAA 10 mgL-1 at 5mm FD + 6BA 150 mgL-1 at 8mm FD; -3: Carbaryl 1020 mgL-1 at 5mm FD; -4: 6BA 100 mgL-1 at 8mm FD; -5: 6BA 50 mgL-1 at 5mm FD + 6BA 50 mgL-1 at 8mm FD; and -6: Untreated control. The variables measured were: fruits/cm2 branch cross sectional area (BCSA), fruits/100 flower clusters, fruit set distribution, hand thinned fruits/cm² BCSA, hand thinned fruits/m, fruit weight, length (L), diameter (D), L/D relationship and firmness; and fruit commercial size classification. Treatments 1, 2, 3 and 4 significantly reduced the number of fruits/cm² BCSA in comparison with the control. The numbers of fruits/100 flower clusters was also significantly different from the control in treatments 1, 2, and 4. Treatment 5 did not differ from the control in both variables. Treatments 1, 2, and 4 had a higher amount of spurs without fruits than treatment 3, 5 and 6. After chemical applications, hand thinned fruits/cm² BCSA and hand thinned fruits/m were fewer in treatments 1, 2, 3 and 4. Fruits treated with BA had higher weights and diameters compared with the control. Fruit L/D relationship and firmness did not differ among treatments. BA treatments produced the larger fruit commercial sizes. The different combinations of NAA + 6BA and 6BA at 100 mgL-1 were effective as thinners. Repeated applications of BA at 50 mgL-1 did not have a good thinning effect but they increased fruit weight, diameter and length.
Dussi, M.C., Gharding, G., Reeb, P., De Bernardin, F. and Apendino, E. (2006). FRUIT THINNING EFFECTS IN THE APPLE CV. ´ROYAL GALA´. Acta Hortic. 727, 401-408
DOI: 10.17660/ActaHortic.2006.727.48
benzyladenine (BA), Carbaryl, NAA, firmness, fruit size

Acta Horticulturae