Paclobutrazol Reduces Vegetative Growth and Enhances Flowering and Fruiting of Mature 'JH Hale' and 'Red Skin' Peach Trees

摘要

Vegetative and reproductive responses of mature peach (Prunus persica) trees cultivars 'J.H. Hale' and 'Red Skin' on 'Montclar' peach seedling rootstock to soil applied paclobutrazol (PBZ) were examined Under Moghan, Iran environmental conditions. PBZ was soil drenched at 0 (control), 0.5 (L-PBZ), and 1.5 g.tree(-1) a.i. (H-PBZ) with six replications. PBZ significantly reduced vegetative growth during the experiment. Total pruning dry weight, shoot growth, and trunk cross sectional area of PBZ-treated trees were reduced compared to those of controls, with H-PBZ being more effective than L-PBZ. PBZ treatments advanced flowering and time of fruit harvest on 'J.H. Hale' and 'Red Skin' by 2-4 and 2-7 days, respectively, ill the following season. PBZ treatments increased flower and fruit densities, fruit set. crop density, yield and yield efficiency in both cultivars in the following season. Similarly, the total number of fruits in the second season was increased in both cultivars by PBZ treatments. However, fruit size was smaller in the PBZ treatments than control. The effects, of PBZ treatments and cultivars oil total Soluble solids, total fruit sugars, and fruit acidity were not significant. Leaf N and P was not influenced by any PBZ treatments, but Ca and K concentrations were increased by H-PBZ. In conclusion, H-PBZ was the most effective in reducing vegetative growth and promoting reproductive growth.