Predicting broadleaf weed populations in maize from the soil seedbank

Abstract

Investigations over three years studied the relationship between weed seeds in the soil seedbank and the resultant populations of broadleaf weeds in maize fields Plots were protected from preemergence herbicide after which soil samples (100 mm) were collected and weed seeds therein enumerated Emerged weed seedlings in field plots were counted over the following 8 weeks Up to 67 broadleaf weed species were identified although not all were found at every site and some were specific to a region or soil type On average 2182 of the seed in the soil seedbank emerged For most weeds strong linear relationships were noted between seedling numbers and the seed numbers in the soil although for some like white clover (Trifolium repens) only a weak relationship was observed In the case of fathen (Chenopodium album) which had the largest seedbank there was evidence of asymptotic behaviour with seedling emergence levelling off at high seed numbers