عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In order to determine changes in weed flora in wheat fields of Savojbolagh and Shirvan counties, the results of studies in 2000 and 2010 were compared. Based on the first study (2000) in Savojbolagh County, 57 species belong to 19 families and in Shirvan county 28 species belong to 13 families were detected. In second study (2010) in Savojbolagh County, 53 species belong to 19 families and in Shirvan county 53 species belong to 18 families were detected.Some species of flora were removed and some new species were added to the flora. Abundance index of some species were changed, some species lost their dominance and others became dominant. Any change in the dominance index due to changes in frequency, density, or both, can be related to many factors. In Savojbolagh dominance of many species including knotweed (Polygonum aviculare), bedstraw (Galium aparine), lepyrodiclis (Lepyrodiclis holosteoides). speedwell (Veronica camplypoda) and fumitory(Fumaria vaillantii) were due to increase in density but in Shirvan dominance of many species including common lambsquarters(Chenopodium album), hairy vetch(Vicia villosa), (Goldbachia laevigata) and Canada thistle (Circium arvense) were due to increase in density, except for knotweed (Polygonum aviculare) was due to increase in frequency. Any change in the abundance of grass weed species in wheat fields of Savojbolagh indicate that the management methods applied for these species have failed after a decade and winter wild oat (Avena ludviciana) and feral rye (Secale cereale) remain as the dominant grass weed species. Change in abundance index of broadleaf weed species in Savojbolagh and dominance of some species such as knotweed, lepyrodiclis and speedwell showed that change flora of broadleaf weeds was in response to weed management methods. Introduction of new species to the wheat fields of Shirvan was considerable. The management methods applied were clearly the reasons for the floral changes, we should now adopt new strategies to manage the new species.
Barberi, P. and Cascio, B. L. 2000. Long-term tillage and crop rotation effects on weed seedbank size and composition. Weed Res. 41: 325-340.
Bukun, B. 2005. Weed flora changes in cotton growing areas during the last decade after irrigation of harran plain in sanliurfa, turkey. Pakistani. J. of Bot. 37: 667-672.
Ervio, L-R. and Salonen, J. 1987. Changes in the weed population of spring cereals in Finland. Annal. Agri Fenn. 26: 210-226.
Fogelforse, H. 1979. Changes in the flora of farmland (arable land) with special regard to chemical weed control. A literature survey in rep. 5 Swedish Universal. Agriculture. Science. Departement. Ecology. Environ. Research. Uppsala. 65 pp.
Hasannejad, s. Alizadeh, H. Mozaffarian, V. Chayichi, M. and Minbashi, M. 2010. Survey of density and abundance for barely fields weeds in Azarbayjan-e-sharghi province. Iran. J. Weed Sci. 5: 69-90.
Hilgenfeld, K. L., Martin, A.R., Mortensen, D. A and Mason, S. C. 2004. Weed management in a glyphosate resistant soybean system. Weed species shifts. Weed Technol. 18: 284-291.
Hyvonen, T. Ketoja, E. and Salonen, J. 2003. Changes in the abundance of weeds in spring cereal fields in Finland. Weed Res. 43: 348-356.
Manley, B. S., Wilson, H. P. and Hines, T. E. 2002. Management programs and crop rotations inﬂuence populations of annual grass weeds and yellow nutsedge. Weed Sci. 50: 112-119.
Milanova, S., Baeva, G., Nakova, R., Maneva, S., Chavdarov, L., Stoimenova1, G. and Tatjana, V. 2007. Some changes and trends in the weed communities in last years in Sofia region. Proceeding 9th Symposium on Flora of Southeastern Serbia and Neighbouring Regions. 55-61.
Minbashi Moeini, M., Baghestani, M. A. and Mashhadi H. R. 2008. Introducing an abundance index for assessing weed ﬂora in survey studie. Weed Biol & Manag. 8: 172-180.
Minbashi, M., Baghestani, M. Rahimian, H. and Aleefar, M. 2009. Weed Mapping for Irrigated Wheat Fields of Tehran Province using Geographic Information System (GIS). Iran. J. weed Sci. 4: 97-118.
Norsworthy. J. K. 2008. Effect of tillage intensity and herbicide programs on changes in weed species density and composition in the southeastern coastal plains of the united states. Crop protect. 27: 151-160.
Nowrouz Zadeh, S. 2009. Investigation on using of GIS (Geographic Information System) for weed mapping of dryland and irrigated wheat fields of Khorasan. Final Report. Agriculture and Natural Resources Center of Khorasan Razavi.Mashhad.77 pp.
Storkey, J. R. Stephen, R. M and Cussans, J. W. 2010. Using assembly theory to explain changes in a weed flora in response to agricultural intensification. source: Weed Sci. 58:39-46.
Thomas, A. G. 1985. Weed survey system used in Saskatchewan for cereal and oilseed crops. Weed Sci. 33: 34-43.
Yin, L. Cai, Z. and Zhong, W. 2006. Changes in weed community diversity of maize crops due to long-term fertilization. Crop Protect. 25: 910-914.