Abstract
Defoliation of the panicle of Rumex crispus L. (curled dock) at anthesis had little effect on the number of seeds (nuts) produced but lead to a very severe reduction in total seed weight per panicle and in the size of individual seeds. In particular the proportion of larger seeds was reduced drastically. The seeds from defoliated plants germinated more rapidly and had less precise requirements for germination than those from untreated plants. They did not suffer any loss of viability. A microscopic examination of cross sections of seeds revealed that seeds from defoliated plants had thinner walls (investing structures). They also exhibited a higher absorptive capacity for water. This information provides an important basis for further studies on the biological control of this weedy species.