在割胶树和不割胶树枝条上施用乙烯利的试验证明,经刺激的割胶树的茎围增长受到影响,这不仅由于刺激增产消耗了同化物,而且由于乙烯利对形成层活动直接的调节作用。乙烯利刺激割胶树茎围增长虽然受到抑制,但由于形成层的活动,韧皮部径向增长的数量(包括乳管列数)受到的影响很小。原因在于乙烯利对形成层活动作用的特点:抑制木质部的增长,促进韧皮部的径向增长。 Experiments with ethephon on tapping and non-tapering branches proved that the growth of the stems of the excised tapping tree was affected not only by the assimilation of stimuli but also by the regulation of ethephon directly on cambium activity . Although ethephon stimulated the growth of cuttings, the growth of phloem was restrained, but the amount of radial growth of phloem (including the number of ducts) was little affected by the formation layer activity. The reason is that ethephon has the characteristic of action on the cambium: inhibiting the growth of xylem and promoting the radial growth of phloem.