In wind-pollinated plants, resource allocation to male function often increases with plant height. This is because taller plants can increase male fitness by increasing pollen dispersal distance (stature effect). To deepen our understanding of this male-biased allocation strategy, we examined how a wind-pollinated plant, Ambrosia artemisiifolia , can respond to damage of a main stem by experimentally cutting a stem tip. We prepared one treated group (A: stem tip cutting) and three controls (B: 2 leaves cutting, C: 4 leaves cutting, D: non-treated). After three months, the height of a main stem was significantly shorter in A than in B-D, but there was little difference among four groups in the height including lateral branches. Also, there was little difference in the number of lateral branches among groups. Consequently, there was no significant difference in the number of male and female flowers among groups. These results showed that the damage of the main stem did not affect sex allocation. The elongation of lateral branches probably compensated for the stature effect.