Seed production and dormancy in Rumex crispus. II. The effects of removal of various proportions of flowers at anthesis

Abstract

Systematic removal of 25, 50, and 75% of the flower whorls from panicles of Rumex crispus L. (curled dock) reduced the total yield per panicle of seeds and fruits in comparison to control plants. However, the mean weight per seed was progressively higher as a greater proportion of the whorls was removed.For untreated plants, seeds borne toward the tips of branches were always lighter than those found near the junctions of branches with the main rachis. Seeds from the lower portion of the panicle were generally larger than those from the upper branches. On treated plants individual seed weight became less variable over the whole panicle.Although seeds from all treatments were equally viable, the larger seeds from treated plants exhibited a greater amount of dormancy under several germination regimes. This increased dormancy might be attributed to the thicker investing structures of larger seeds.