Abstract

Variation in seed dormancy and light sensitivity was studied in Alopecurus myosuroides and Apera spica-venti. Seeds were collected from different populations, at different dates and from plants emerging in autumn or spring, and used in four experiments. In the first experiment, initial dormancy was investigated in light and darkness. In Expt 2, buried seeds were exhumed on 16 occasions, from September 1997 to March 2000, and germinated in light, in darkness and after a 5-s light exposure. In Expt 3, emergence was recorded for seeds sown in pots outdoors. In Expt 4, stratified seeds of A. myosuroides only were exposed to photon irradiance ranging from 0.1 to 25 600 mu mol m(-2). Variation was high among seed collections, but both species showed winter annual dormancy patterns. Apera spica-venti germinated to high percentages in autumn but negligibly in spring. Alopecurus myosuroides germinated less in spring when tested in darkness and after a short light exposure and emerged poorly in spring, which reflected photo-desensitisation during cold stratification. We conclude that the peak of emergence in A. myosuroides, and to some extent in A. spica-venti, is largely regulated by exposure to light interacting with low-level dormancy. This offers valuable information regarding optimal timing of weed control measures.

Keywords

blackgrass; emergence; grass weeds; irradiance; loose silkybent

Published in

Weed Research
2009, Volume: 49, number: 3, pages: 261-270

SLU Authors

• Andersson, Lars

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

• Åkerblom Espeby, Liv

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1111/j.1365-3180.2009.00695.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/26408