Harvest Weed Seed Control: Seed Production and Retention of <i>Fallopia convolvulus</i>, <i>Sinapis arvensis</i>, <i>Spergula arvensis</i> and <i>Stellaria media</i> at Spring Oat Maturity

Abstract

If seeds retained on weeds at crop harvest could be collected and removed by the combine harvester, weed infestation could be reduced in the following years. We estimated the proportion of weed seeds that could be removed at oat harvest. The seed production and shedding pattern of Fallopia convolvulus, Sinapis arvensis, Spergula arvensis and Stellaria media, were assessed in two spring oat fields in Denmark during 2018 and 2019. Ten randomly chosen plants of each species were surrounded by a porous net before flowering. The start time of seed shedding was recorded, and the seeds were collected from the nets and counted weekly until oat harvest. Just before harvest, the retained seeds on the weed plants were counted. The ratio between harvestable seeds and shed seeds during the growing season was determined. On average 260, 195, 411 and 316 seeds plant−1 were produced by F. convolvulus, Sinapis arvensis, Spergula arvensis and S. media, respectively, of which in average 44%, 67%, 45% and 56% of the seeds were retained on the plants at harvest. There was a strong, positive correlation between the weed biomass and the total seed production.

Keywords

• hwsc
• seed shedding
• soil seed bank
• spring cereals