Post-dispersal seed predation of four weed species in maize fields

To evaluate post-dispersal seed predation of weeds in maize fields، factorial experiments with four replications were conducted in 2007 in Mashhad and Chenaran، NE of Iran using four common weed species in maize field. Treatments were weed species، sampling periods and cages. Removal of Amaranthus retroflexus، Chenopodium album، Sorghum halepense and Datura stramonium were measured during seven sequential weeks in two maize fields from August until October 2007 Wire mesh cages were used to determine the predation by avian predators. Invertebrate seed predator activity-density was monitored using pitfall traps. Seed removal was significantly different between fields and among species. Post-dispersal seed predation was higher in Chenaran maize field (55درصد) than Mashhad field (47درصد) that could be resulted from difference in irrigation method and the number of invertebrate predators. Except some fluctuations during the predation period، seed removal decreased toward the end of experiments in both places. Cage exclusion had no significant effect on predation in both places، showing no significant removal of seeds by birds. Invertebrates were the most important predators in both fields and ants were the main invertebrateseed predators but other seed eater invertebrates like crickets and different seed eater carabid beetles were caught in to pitfalls too