Author
GRUNDY, A - HORTICULTURE RES INT | |
PETERS, N - UNIVERSITY OF BRISTOL | |
RASMUSSEN, I - DANISH INSTITUTE AG SCI | |
HARTMANN, K - UNIVERSITY OF ERLANGEN | |
SATTIN, M - CNR (ITALY) | |
ANDERSSON, L - SVENSK LANDBOUW UNIV | |
MEAD, A - HORTICULTURE RES INTL | |
MURDOCH, A - UNIVERSITY OF READING | |
Forcella, Frank |
Submitted to: European Weed Research Society Symposium Proceedings
Publication Type: Proceedings Publication Acceptance Date: 12/1/2001 Publication Date: 7/21/2002 Citation: Grundy, A.C., Peters, N.C.B., Rasmussen, I.A., Hartmann, K.M., Sattin, M., Andersson, L., Mead, A., Murdock, A.J., Forcella, F. 2002. Emergence of Chenopodium album and Stellaria media under different climatic conditions. Proceedings of European Weed Research Society Symposium. p. 5-6. Interpretive Summary: A joint experiment sponsored by the European Weed Research Society involved eight research sites (seven in Europe and one in the USA). The purpose was to understand how differing climatic conditions affect the ability of lambsquarters (Chenopodium album), a spring-germinating species, and chickweed (Stellaria media), a species that germinates in autumn and spring, to germinate seeds. At all sites the same number of seeds were sown in the same substrate (peat), at the same depth (2 cm), and on approximately the same dates for two years (November 1999 and 2000); seedling emergence was monitored in the same fashion; and the same types of microclimate information were recorded. Seeds from three sources (Sweden, England, and Italy) were sown at each site. The cumulative proportions of lambsquarters seeds that emerged over entire growing seasons were high for locations with low winter temperatures and low for sites with high winter temperatures, perhaps because very low winter temperatures relieved seed dormancy. All seed accessions behaved similarly in general, but some variation did occur, which probably was due to initial differences in seed viability among sources. The timing of emergence was similar at all sites and for all sources, which makes developing predictive tools for crop consultants much easier. Few consistencies were apparent for chickweed, and more research will be necessary on this species before work can begin on developing predictive tools. These preliminary results will be useful for weed scientists to understand and predict the behavior of lambsquarters so that more effective control strategies may be developed in regions where lambsquarters is an important weed, especially the northern USA. Technical Abstract: A joint experiment was conducted at seven sites in Europe and one in the USA (Minnesota). The objective was to understand how differing climatic conditions affect the ability of Chenopodium album, a spring-germinating species, and Stellaria media, a species that germinates in autumn and spring, to germinate seeds. At all sites the same number of seeds were sown at 2 cm depth in peat soil and on approximately the same dates for two years (November 1999 and 2000); seedling emergence was monitored twice weekly; and soil temperature and rainfall data recorded. The three seed accessions sown at each site were from Sweden, England and Italy. The cumulative proportion of C. album seeds that emerged was inversely related to winter temperatures, perhaps because very low winter temperatures relieved seed dormancy. All seed accessions behaved similarly in a qualitative sense, although some quantitative differences appeared, reflecting variability in initial seed viability among accessions. Patterns of emergence timing at all sites and accessions were similar, which greatly facilitates the likelihood of developing predictive emergence models for this species. Fewer consistencies were apparent for S. media, and considerably more research will be necessary on this latter species before modeling activities can begin. These preliminary results will be useful to weed scientists in regions where lambsquarters is an important weed, such as throughout the northern half of Eurasia and North America. |