ANNUAL LOSSES OF WEED SEED DUE TO PREDATION ON CEREAL FIELDS

Annual seed losses due to post-dispersal seed predation have seldom been quantified for arable weed species, but may be of significance for natural weed control, especially if they can be manipulated. We measured rates of predation and seed shed in four cereal fields and integrated these into estimates of annual seed losses, which ranged from 32 to 70% when assuming continuous exposure of seeds to predators from seed shed till crop harvest. The results suggest that seed predation can account for a large proportion of the ‘missing’ seeds observed in seed balance studies and may shape the population dynamics of arable weeds.