PP333对密植桃树早实丰产作用的研究

在１×１×１．５ｍ的密植桃园（５３４株／亩）定植春蕾和无核早二品种半成苗，于当年生长期和落叶休眠期，用不同剂量ＰＰ３３３（０．１５，０．３０，０．４５，０．６０ｇ／株）进行土壤施入。ＰＰ３３３具有控制树冠、促进成花、降低节间长度和成花始节位、增大根冠比、加大木质部导管密度和粗度、改善地上部营养和水分状况等作用，早实丰产效果明显．

The Study of the Effect of PP333(Paclobutrazol)on the Early Bearing and High Yield of Densely Planted Peach Trees

In a 1×1×1.5m densely planted peach orchard (534trees/mu ),the half-grown seedlings of two breeds, Chunlei and Wuhezao, are field planted , and PP333 with dif-ferent dosage(0.15,0. 30,0. 45,0. 60g/tree) is applied into the soil during the growing periodand deciduous rest period in the same year of field planting.Some obvious effects are ob-tained : the size of the tree crowns is controlled, the flowering is promoted, the lengths be-tween branch knots and the newborn positions of flower buds are reduced, the root-top ratiois increased,the density and the width in diameter of woodv conduits are increased , the nutri-tion and moisture content of the upper soil layer are improved. The average quantity for oneyear old peach seedling reached 36.25 fruits/tree,1.81～2.27kg/tree, and 966.54～1212.18kg/mu.Two year old peach seedlings reached 97.69 fruits/tree,4. 89～6.11kg/tree,and 261. 26～3262.7kg/mu. Three year old peach seedling reached 112. 92 fruits/tree andthe actual output was 3030.78kg/mu. The effect will be best when the applied dosage is be-tween 0.30～0.45g/tree (0.24～0. 36g/m￣2).The applying period depends on the tree crownand distances between plants and rows.