PACLOBUTRAZOL REDUCES SOME NEGATIVE EFFECTS OF SALT STRESS IN PEACH

One-year-old rooted cuttings of 'Nemaguard' peach [Prunus persica (L.) Batsch.] were irrigated with 0, 1000, or 2000 mg . L(-1) salts under greenhouse conditions to study the effect of foliar paclobutrazol (PBZ ) application on salt stress response. Salinity reduced growth of nont reated plants by approximate to 50%, but only by approximate to 30% fo r PBZ-treated plants. PBZ-treated plants also had less defoliation and fewer leaves per plant showing salt stress symptoms, and had higher r ates of leaf gas exchange than nontreated plants. PBZ application gene rally reduced Na+ and Cl- contents in leaves, roots, and stems, regard less of salt treatment. Furthermore, total Na+ per plant in PBZ-treate d plants was about half that found in nontreated plants, although tota l Cl- per plant was reduced by PBZ in only one of two salt treatments, The data suggested that PBZ promoted salt stress avoidance in peach b y reducing the uptake and accumulation of harmful Na+ and Cl- ions in plant tissues.