PP_（333）在杏、李树上的喷施效应

本试验以曹杏、香蕉李为试材，采用喷施方式，研究了在萌芽期、新梢生长初期喷布不同浓度的ＰＰ_（３３３）。结果表明：ＰＰ_（３３３）显著地抑制了新梢的加长生长，新梢的粗度也有所增加，提高了叶绿素合量和光合强度。不同处理比较试验显示，杏树喷施最佳浓度为２５０μｇ／ｇ，最佳喷布时间为新梢生长初期。李树最佳喷施浓度为４５０μｇ／ｇ。

THE EFFECT OF SPRAYING PACLOBUTRAZOL (PP33) ON APRICOT AND PLUM TREES

Apricot trss is quite sensitive to PP(333). In the case of soil-application, larger dose would cause the lateral branches slender and cause the flowering wood lowering, while smaller dose would not suppress the growth enough1,3], Information about the application of PP(333) on plum trees are quite rare. In this test, Cao-apricot and Xiang jiao-plum trees were chosen as test material, PP(333) of different concentration was sprayed in the early period of growth of young shoots in the pullulation period. The test shows that PP(333) significantly inhibited the growth in length of the young shoots, their thickness increased and PPs(333)also increased the chlorophyllous content and photosynthetic intensity. Comparison test of different treatments reveals that when spraying apricot trees, the optimum concentration is 250ppm, the optimum time of spraying is in the early period of growth of young shoots, while for plum trees the optimum concentration is 450ppm.