Efeito do citronelol sobre a germinação e desenvolvimento do amendoim-bravo (Euphorbia heterophylla L.)

Abstract

Citronelol 3,7 dimethyt-6-octen-1-ol, obtained from orange pericarp showed allelophatic action on the germination and growth of Euphorbia heterophylla L. (wild poinsettia). Exposure of seeds to small volumes of citronelol, during 5 hours, ranging 1,0 to 40 1,0 (5,5 to 220 ), in sealed containers followed by inhibition, showed that the dose fo 2,9 caused a 50% reduction of germination (LD50), as indicated of probit analysis. The estimated mitotic index between 2.0 and 5.0 mm of root tips from germinated seeds exposed to the LD50 dose for 5 hours indicated that the inhibition of root growth by citronelol, may be associated with mitosis inhibition (X2 — 88,9 p < 0,001). At the same conditions citronelol also reduced the lenght, diameter of hypocotyl, and the lenght, number of cells representig the diameter and the cortex of hypocotyl. The data presented here indicate the need of further experiments of weed control in the field.