PP_(333)对初果期苹果树的影响

THE EFFECT OF PP333(PACLOBUTRAZAL) ON FIRST BEARING APPLE TREES

叶面喷施PP_(333),明显抑制了初果期国光苹果新梢的前期生长,处理后两周作用开始明显,处理后七周作用消失,新梢重新迅速生长。叶面喷施B_9与PP_(333)作用相似,抑制效果比PP_(333)略强,有效期也略长。在相同剂量情况下,土施PP_(333)较叶面喷施开始作用时间晚,对秋梢抑制作用强。土施及叶面喷施PP_(333)对成花的促进作用不如B_9显著。试验结果还表明在叶面喷施情况下,PP_(333)在树体内的移动性极差。

Foliar spray of Paclobutrazol to first bearing 'Ralls' apple trees mar- kedly inhibited the spring shoot growth.The significance appeared 3d week after treatment, and disappeared in 7th week. Then the shoot treated grew more rapidly than ck. Soil application became effective later, but reduced fall shoot growth significantly. The effect of B9 (Daminozide) on shoot growth by foliar spray was similar to PP333. Treatment with B9 increased significantly the amout of return bloom, but both Soil application and foliar spray of PP333 had no effect on it. The study also showed that PP333 by foliar spray is immobile in apple trees.