The effect of seed dormancy on percentage and rate of germination in Polygonum persicaria, and its relevance for crop-weed interaction

Changes in germination percentage and germination rate of Polygonum persicaria resulting from loss of primary dormancy during chilling of imbibed seeds were quantified. Both percentage and rate of germination increased with increasing loss of dormancy. It was concluded that retardation of germination caused by dormancy was not due to dormancy release prior to germination, but to retardation of the germination process itself. When evaluated in relation to competition between sugar-beet and P. persicaria, the effect of dormancy on the germination percentage was more important than the effect on germination rate, but for an accurate prediction of yield loss, the latter effect cannot be neglected.